analysis of alternatives for the use of trichloroethylene

ANALYSIS OF ALTERNATIVES

1

Analysis of Alternatives for the use of trichloroethylene as an

extraction solvent for removal of process oil and formation of the

porous structure in polyethylene based separators used in lead-acid

batteries

Legal name of applicant(s): ENTEK International Limited

Mylord Crescent

Camperdown Industrial Estate

Killingworth, Newcastle upon Tyne NE12 5XG, UK

Submitted by: ENTEK International Limited

Substance: Trichloroethylene, CAS 79-01-6; EC 201-167-4

Use title: Use of trichloroethylene as an extraction solvent for removal of process oil and formation

of the porous structure in polyethylene based separators used in lead-acid batteries

Use number: USE 1

2

CONTENTS

SUMMARY ................................................................................................................................................................. 7

ACTIONS AND TIMEFRAME FOR IDENTIFICATION AND DEVELOPMENT OF A SUITABLE AND

AVAILABLE ALTERNATIVE. ......................................................................................................................... 15

2. ANALYSIS OF SUBSTANCE FUNCTION ....................................................................................................... 17

2.1 OVERVIEW AND BACKGROUND .................................................................................................................. 17

2.2 MANUFACTURE OF POLYETHYLENE-BASED SEPARATORS - PROCESS DESCRIPTION ................. 20

2.3 CONSIDERATION OF OBSTACLES OR DIFFICULTIES IDENTIFIED OR EXPECTED IN RELATION TO

FINDING AN ALTERNATIVE FULFILLING OR REPLACING THE EQUIVALENT FUNCTION OF TRI. 24

3 ANNUAL TONNAGE .......................................................................................................................................... 30

4 IDENTIFICATION OF POSSIBLE ALTERNATIVES ................................................................................... 31

4.1 LIST OF POSSIBLE ALTERNATIVES ............................................................................................................. 31

4.2 DESCRIPTION OF EFFORTS MADE TO IDENTIFY POSSIBLE ALTERNATIVES.................................... 41

4.2.1 Research and Development ............................................................................................................................ 42

4.2.1.1 Solvent Alternatives ............................................................................................................................ 42

4.2.2 Manufacturing Alternatives ............................................................................................................................ 55

4.2.3 Consultations .................................................................................................................................................. 65

5. SUITABILITY AND AVAILABILITY OF POSSIBLE ALTERNATIVES ................................................... 67

5.1 INTRODUCTION ................................................................................................................................................ 67

5.2 N- HEXANE ........................................................................................................................................................ 67

5.2.1 Substance ID and properties ........................................................................................................................... 67

5.2.2 Technical feasibility ............................................................................................................................ 69

5.2.3 Reduction of overall risk due to transition to the alternative .......................................................................... 75

5.2.4 Economic feasibility ............................................................................................................................ 78

5.2.5 Availability ..................................................................................................................................................... 83

5.2.6 Conclusion on suitability and availability for n-hexane ................................................................................. 83

5.3 DICHLOROMETHANE ...................................................................................................................................... 85



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5.3.4 Economic feasibility....................................................................................................................................... 92

5.3.5 Availability ..................................................................................................................................................... 93

5.3.6 Conclusion on suitability and availability for dichloromethane ..................................................................... 93

5.4 TETRACHLOROETHYLENE ............................................................................................................................ 95




5.4.4 Economic feasibility ...................................................................................................................................... 102

5.4.5 Availability ..................................................................................................................................................... 103

5.4.6 Conclusion on suitability and availability for tetrachloroethylene ................................................................. 103

5.5 VERTREL® SDG ................................................................................................................................................ 105

5.5.1 Substance ID and properties ................................................................................................................ 105

5.5.2 Technical feasibility ....................................................................................................................................... 108


5.5.4 Economic feasibility ............................................................................................................................ 116

5.5.5 Availability ..................................................................................................................................................... 117

5.5.6 Conclusion on suitability and availability for Vertrel® SDG .......................................................................... 117

5.6 HFE-72DE............................................................................................................................................................ 119





5.6.5 Availability ..................................................................................................................................................... 125

5.6.6 Conclusion on suitability and availability for HFE-72DE .............................................................................. 125

5.7 N-PROPYL BROMIDE ....................................................................................................................................... 126





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5.7.5 Availability ..................................................................................................................................................... 132

5.7.6 Conclusion on suitability and availability for n-propyl bromide .................................................................... 132

5.8 D-LIMONENE ..................................................................................................................................................... 133





5.8.5 Availability ..................................................................................................................................................... 139

5.8.6 Conclusion on suitability and availability for D-limonene ............................................................................. 139

5.9 ACETONE ........................................................................................................................................................... 140





5.9.5 Availability ..................................................................................................................................................... 146

5.9.6 Conclusion on suitability and availability for Acetone ................................................................................... 146

5.10 ASSESSMENT OF TECHNICAL ALTERNATIVES ........................................................................................ 146

5.10.1 Lead Acid Battery Classifications ....................................................................................................... 146

5.10.2 Alternative separator products ............................................................................................................. 147

6 OVERALL CONCLUSIONS ON SUITABILITYAND AVAILABILITY OF POSSIBLE ALTERNATIVES

FOR USE OF TRICHLOROETHYLENE AS AN EXTRACTION SOLVENT FOR REMOVAL OF PROCESS

OIL AND FORMATION OF THE POROUS STRUCTURE IN POLYETHYLENE BASED SEPARATORS

USED IN LEAD-ACID BATTERIES ....................................................................................................................... 150

6.1 OVERALL CONCLUSION................................................................................................................................. 150

6.2 ACTIONS AND TIMEFRAME FOR IDENTIFICATION AND DEVELOPMENT OF A SUITABLE AND

AVAILABLE ALTERNATIVE. ......................................................................................................................... 154

ANNEX I – JUSTIFICATION FOR CONFIDENTIALITY CLAIMS ................................................................. 160

REFERENCES ........................................................................................................................................................... 163

WEB REFERENCES ................................................................................................................................................. 165

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List of Abbreviations

AoA Analysis of Alternatives

C&L Classification & Labelling

CAS Chemical Abstracts Service

CEFIC The European Chemical Industry Council

CLP Classification, Labelling and Packaging

CMR Carcinogen, mutagen or reproductive toxin (as defined in Article 57 of

REACH)

CSR Chemical Safety Report

DCM Dichloromethane (methylene chloride)

ECHA European Chemicals Agency

EEA European Economic Area

eSDS extended Safety Data Sheet

ESR Existing Substances Regulation

EU European Union

GHG Greenhouse gas

LABS Lead acid battery separator

NPV Net present value

PBT Persistent, Bioaccumulative, and Toxic (as defined in Article 57 and

Annex XIII of REACH)

PEC Predicted environmental concentration

PNEC Predicted no effect concentration

RAR Risk Assessment Report

RMM Risk Management Measure

SEA Socio Economic Analysis

SEAC Socio Economic Analysis Committee

SLI Starting, lighting, and ignition

SVHC Substance of Very High Concern

TCE or Tri-CE or

TRI

Trichloroethylene

UHMWPE Ultra high molecular weight polyethylene

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USE OF TRICHLOROETHYLENE AS AN EXTRACTION

SOLVENT FOR REMOVAL OF PROCESS OIL AND

FORMATION OF THE POROUS STRUCTURE IN

POLYETHYLENE BASED SEPARATORS USED IN LEAD-ACID

BATTERIES

SUMMARY

Entek International Ltd. is a producer of lead acid battery separators. The function of a battery separator is to

prevent the positive and negative electrodes of the lead-acid battery from touching and short-circuiting,

whilst allowing the electrodes to communicate via ion transport through the electrolyte (i.e. sulphuric acid).

Battery separators have 50 to 60% porosity with a mean pore diameter of approximately 0.1 micron: these

pores are large enough for ion transport through the separator thickness, but small enough to ensure that

dendrites do not grow through the separator and cause a short circuit. The battery separator is formulated to

retain structural and electrical integrity for multiple years whilst submerged in sulphuric acid solution,

challenged by the vibration and jarring that a battery is subjected to under the bonnet of an automobile and

with exposure to temperature extremes.

Battery separators are a specialty product with very specific technical qualities and there are only a few

manufacturers, especially as compared to the complete battery. The manufacturing process for battery

separators requires a large capital investment and a high degree of technical skill in order to meet quality and

cost targets. Because the product is essential to the modern, sealed flooded lead-acid battery – the most cost-

effective and reliable Starting, Lighting and Ignition (SLI) power source available for automobiles – major

battery makers seek to ensure their uninterrupted supply and consistent performance of the material by

requiring contractual commitments for supply and severe limitations on the separator producer’s ability to

change materials, process or product specifications.

During the manufacture of ENTEK’s polyethylene separators, precipitated silica and UltraHigh Molecular

Weight PolyEthylene (UHMWPE) are combined with a process oil and various minor ingredients to form a

mixture that is extruded at elevated temperature to form an oil-filled sheet. The oil-filled sheet is calendered

(rolled out) to the desired thickness, and the majority of the process oil is extracted with TRI. The sheet is

then passed through a dryer and hot air oven to remove the TRI, leaving behind a microporous structure in

the separator sheet. Finally, the sheet is cut at multiple positions to form rolls of separator sheet that have the

appropriate profile for customers’ battery designs. The term “profile” refers to the width, backweb

thickness, number of ribs, rib height, and shoulder design of the separator as shown in Figure 1.2.

The conclusion of the analysis of alternatives is that there are currently no alternatives that are both suitable

and available to the applicant for the replacement of the Annex XIV substance function. A number of

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possible solvent alternatives have been tested at laboratory scale or otherwise analysed by ENTEK.

Although it was found that for one or two of the substances there is potential for the replacement of TRI, a

considerable amount of further research is required to determine the commercial feasibility of these

substances.

It is very important to note that all of the described alternatives are still at a very early stage of investigation

and none can be considered commercially feasible without extensive further research and development. It is

important to make a distinction between technical feasibility and commercial feasibility. As used herein,

the criteria for technical feasibility in the early stages of the Stage-Gate Research and Development process

(see Figure 4.11) are simply to show that a porous material can be produced which is chemically compatible

with sulphuric acid (i.e., the electrolyte in a lead-acid battery). Even if technical feasibility can be

demonstrated in the laboratory, commercial feasibility can only be confirmed after economic scale-up of the

manufacturing process and customer qualification of lead-acid batteries containing any battery separator

produced with an alternative solvent.

If ENTEK is able through further research to determine that an alternative substance is commercially

feasible, ENTEK would have to demonstrate to its customers that it can produce separators that consistently

meet customer requirements. Battery manufacturers sell products with multi-year warranties, making them

extremely adverse to risks that could result in higher warranty claims. In addition, battery manufacturers that

produce batteries for original equipment manufacturers are held to very strict standards and any major

product change needs to be approved by these end customers. As a result, it is common for battery

manufacturers to contractually bind battery separator suppliers not to change raw materials, process or

product specifications without prior approval and verification of product performance via extensive lab

testing, field testing, process validation and product validation; the battery manufacturers are similarly bound

by their customers. ENTEK is subject to these restrictions.

Given the long-term promise of battery performance reflected in battery warranties, the logic of ENTEK’s

customers in severely curtailing ENTEK’s ability to make changes in material, process and product is

sound. The performance of a battery separator is derived from the raw materials used to make it, the

equipment the separator was made on, and the operating conditions under which the equipment was run.

Given the number of raw materials and the complexity of a battery separator line, the possible combinations

of material, equipment, and process settings is immense. Prototyping a new process in the lab, engineering

and constructing the commercial solution, finding the correct process conditions and validating the finished

separator product is a lengthy and complex undertaking.

ENTEK is fully aligned with the goal of REACH to reduce the use of substances of concern in the European

Union and research into the possible replacement of TRI is already underway. We recognize that finding a

safe and satisfactory substitute for TRI in our battery separator process is a desirable outcome for all

stakeholders. We do not have that substitute in hand today and it will take a highly skilled research,

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engineering and production team to find and implement that substitute. ENTEK believes that it has the right

team and will continue to invest in the reduction and ultimate potential replacement of TRI.

ENTEK requests a 12-year authorization period to allow continuing with the development of the materials,

process, and products required to satisfy customers and safeguard the well-being of associates, local

community, and the EU at large. In the 12 years requested ENTEK will continue to invest in research to find

a suitable alternative to TRI that will both satisfy the customers’ demands and improve on the human and

environmental safety in the production of battery separators.

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Table 1.1 Summary of essential criteria for substance function

Essential criterion for substance

function

Justification/explanation

1. Task performed by Annex XIV

substance

TRI is used to remove (extract) naphthenic process oil from

polyethylene/silica sheet during the manufacture of battery

separators for onward use in lead acid batteries in

automobiles. The use of TRI maintains fire and explosion

safety in ENTEK’s continuous manufacturing process. It

also enables effective recovery and reuse of TRI by distillation or carbon adsorption/desorption.

Lead acid battery separators are primarily composed of

UHMWPE, precipitated silica and oil. UHMWPE is a

unique polymer that requires a large percentage of process

oil to be extruded in sheet form. This polymer imparts the

necessary mechanical properties for handling in the

manufacturing process. It also imparts high puncture

strength demanded by customers.

There is significantly less oil in the finished product than the

amount of oil required for manufacturing separators;

therefore, a solvent is required to remove the majority of the

oil from the extruded sheet. After removal of the required

amount of oil, the solvent must then be evaporated from the

sheet. This step leaves behind the required amount of

porosity to enable ion transport in a battery.

The solvent must be highly miscible with the process oil and

nonflammable in the ENTEK continuous separator

manufacturing process. After removal of the process oil the

oil/solvent mixture must be distilled into its separate

components for reuse in the manufacturing process.

The solvent is also recaptured after evaporation from the

separator sheet in both vapour and liquid form. The vapour

is recovered through adsorption/desorption in a carbon bed

system and the liquid is phase separated from the condensed

steam/solvent mixture formed in the dryer.

2. What critical properties and quality

criteria must the substance fulfill?

Non-flammability

A non-flammable solvent is critical to worker and equipment

safety. Additionally, this characteristic makes it compatible

with the ENTEK continuous manufacturing process.

A high degree of solvency with process

oil

The solvent must have a high degree of solvency for the

process oil so that the oil can be extracted efficiently.

Reasonable vapour pressure for effective

evaporation

The vapour pressure determines the ability of the solvent to

be evaporated and recovered from the continuous process, enabling recycling of the substance.

Condensable in a steam atmosphere

A reversible recovery of solvent using

distillation and high surface area carbon

The recovery processes require a solvent that can be

condensed in a steam atmosphere and that can be captured on

carbon and subsequently released and recovered.

3. Function conditions

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Ambient/room temperature processing

Effective extraction of oil from the sheet in closed solvent

baths allows efficient use of energy and control and capture

of solvent vapour. The recovery of process oil is

accomplished through distillation of the oil TRI mixture removed from the extractors.

Recovery of process solvent and process

oil

TRI is recovered in both vapour and liquid form at different

points in the manufacturing process. Liquid TRI is

recovered via distillation of the oil/TRI mixture and from

phase separation of the water/TRI mixture condensed during

the drying stage. Finally, TRI vapour is recovered through

adsorption/desorption in the carbon beds. The recovered TRI

is then reused in the ENTEK continuous separator manufacturing process.

4. Process and performance constraints

Product

Upon evaporation of the solvent, the finished separator must

have sufficient porosity and wettability to provide low

electrical (ionic) resistance.

Performance of the separator in lead acid

batteries and acceptance of product by customers.

It is essential that the separator provides mechanical integrity

so that the separator can be enveloped at high speeds and to

prevent grid wire puncture during battery assembly or

operation. It is also essential that any trace amount of the

solvent left in the separator will not negatively affect the electrochemical performance of the lead acid batteries.

Compatibility with the process equipment

for making polyethylene separators.

TRI is stable and nonreactive with the grade of Stainless

Steel used throughout the ENTEK plant for equipment that

handles solvent (e.g. piping, valves, fittings, carbon beds,

extractor and dryer).

5. Is the function associated with another

process that could be altered so that the

use of the substance is limited or eliminated?

There are two main processes involving TRI:

1) The extraction of process oil from the separator sheet

to reduce the oil content from about 65% by weight to about 15% by weight in the finished product.

2) The recovery and recycling of the TRI that allows

reuse of the solvent with a high degree of efficiency.

Both processes allow battery separators to be manufactured

efficiently in a continuous process with good control of releases.

Both processes are interdependent and specifically designed

for the use of TRI. The possibilities for using an alternative

substance are analysed and the associated process changes

considered in this document. It is found that it is not

currently possible for the applicant to use an alternative.

Research concludes that it will be at least 12 years before an alternative could be commercially acceptable.

6. What customer requirements affect the

use of the substance in this use?

Key separator characteristics

The lead-acid storage battery includes positive and negative

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electrodes that are separated from each other by a porous

battery separator. There are five major requirements for the

battery separator, it must:

1) be an electrical insulator to prevent shorting between the

electrodes;

2) be composed of materials that can provide chemical and oxidation resistance;

3) be porous to allow for ionic conduction through the

separator as the battery is discharged;

4) provide the correct mechanical spacing and electrolyte

volume between the electrodes; and

5) run effectively through the separator enveloping line

during battery manufacture.

TRI enables the above key separator characteristics by:

controlled quantitative removal of process oil from

the extruded separator sheet;

evaporation of solvent from the separator sheet to

leave behind the required pore size distribution and percent porosity;

not negatively impacting battery performance even if

trace amounts of residual solvent remain in the finished product; and

closed loop recycling allows for safe reuse of the

solvent in the manufacturing process and delivery of the separator to the customer at a competitive price.

Security of supply

Separators are a critical component in lead acid batteries

used throughout Europe. Security of supply is of critical

importance for battery manufacturers. Each supply location

plays a critical role in the security of supply for the battery

manufacturers. Each supplier is expected to have robust

processes to ensure timely delivery of this critical

component. For example, annual analysis and reporting on

risks to continuous operation and mitigation efforts for these risks, for example, fire safety, may be contractually required.

7. Are there particular industry sector

requirements or legal requirements for

technical acceptability that must be met

and that the function must deliver?

Battery Council International (BCI), Society of Automotive

Engineers (SAE), and European Norm (EN) specifications must be met for both separators and lead-acid batteries.

Table 1.2 (Table 5.1 in the main report) presents a summary of the solvents that were researched for their

potential to replace TRI in the ENTEK process. Each substance is evaluated against the criteria of technical

feasibility, economic feasibility, risk and availability.

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Table 1.2 Summary of findings of the analysis of potential alternatives for substance

Substance Technical feasibility Economic feasibility Similar or additional risk? Availability

n-Hexane (CAS 110-54-3)

Possible on basis of lab trials.

Presents difficulties due to high

volatility.

No – complete change of processing plant

required. Need for compliance with major

accident hazard regulations and need to

relocate plant.

Highly flammable. Neurotoxin and reproductive toxin.

Likely to come under further regulatory pressure in

future.

Presents control difficulties due to high volatility.

Yes

Dichloromethane

(methylene chloride)

(CAS 75-09-2)


Possible.

Considerable time and investment needed to

convert, high business risk on basis of

hazard/risk profile.

Suspect Carcinogen.


future.

Yes

Tetrachloroethylene

(perchloroetheylene)

(CAS 127-18-4)

Possible on basis of lab trials Possible.




Suspect Carcinogen.


future.

Yes

Vertrel® SDG Possible on basis of lab trials. Likely

to be problems with solvent recovery

and recycling.


convert.

Product is 30x more expensive than TRI.

No - (Poor availability of data on the whole substance,

which has not been fully assessed. A constituent is

classified as flammable, harmful by inhalation and for

the environment.)

Yes

HFE 72DE 1,2- trans-1,2-

dichloroethylene


Recovery could be problematic.


convert.

Product is 30x more expensive than TRI

No - (Poor availability of data on the whole substance,

which has not been fully assessed. A constituent is

classified as flammable, harmful by inhalation and for

the environment.)

Yes

n-Propyl bromide (1-

bromopropane)

(CAS 106-94-5)

Possible on basis of lab trials Considerable time and investment needed to



SVHC1 (repro. toxin). Flammable Yes

D-Limonene (CAS 5989-27-5)


Likely to be problems with solvent

recovery and recycling.

Large costs of energy associated with

potential use

Flammable.

Dangerous to the environment.

Yes

Acetone (67-64-1) No – does not perform function to

remove process oil effectively.

Not assessed. Flammable Yes

1 Substance of very high concern (SVHC)

14

Solvent substances that showed some promise in ‘bench-scale’ trials are also under some regulatory scrutiny

in the EU and elsewhere. In recent years, TRI has changed classification as a Cat. 2 carcinogen to a Cat 1B

carcinogen and only very recently has it been decided by ECHA that TRI should be considered to be a non-

threshold carcinogen (for the purposes of authorisation application as least). n-Hexane is a neurotoxin and a

reproductive toxin and tetrachloroethylene and methylene chloride are both currently classified as

carcinogens (Category 2, H351), and are subject to evaluation under CoRAP (now concluded) and

restrictions, respectively. It is therefore unlikely to be sustainable in terms of business planning to invest in

substances with these risk profiles that (based on their properties) would present similar challenges for

emission/release control as TRI. The implementation of a solvent alternative must therefore take account of

possible regulatory changes that would have a severe impact on the use of the substance in the future. It is

clear that for substances that show the possibility for being an alternative to TRI in the ENTEK process,

tetrachloroethylene and methylene chloride, that the regulatory and risk profile of these substances now and

in the future rule them out as likely options. n-Hexane, while used by an ENTEK competitor in France, is

ruled out as it is not compatible with the ENTEK continuous separator manufacturing process due to its

flammability and volatility in addition to its properties as a neurotoxin and a reproductive toxin.

Confidential

15

ACTIONS AND TIMEFRAME FOR IDENTIFICATION AND DEVELOPMENT OF A

SUITABLE AND AVAILABLE ALTERNATIVE.

There are a number of technical barriers to the use of an alternative solvent in the ENTEK continuous

separator manufacturing process. Even with no alternative currently technically feasible, however, we

consider how an industrial-scale trial of a solvent could be implemented and describe that in terms of actions

and associated timescales. First ENTEK must analyse interaction between the alternative solvent and its

equipment and likely retrofit its equipment to adapt the metallurgy to the specific solvent and develop any

appropriate solvent recovery systems. ENTEK must then gain customer approval of its process and resulting

separator products made with the alternative solvent. To gain such approval, ENTEK must make a

significant quantity of samples for its various customers to test in the production of batteries. For the

customer qualification of the process, the samples must be made on the production equipment that will be

used to manufacture separators on an ongoing commercial basis. To avoid cross-contamination with TRI,

these samples can only be run during a temporary plant shutdown period using the existing plant

infrastructure. Concurrently, ENTEK would undertake the engineering study to design the converted plant

and the trial results would feed into that engineering work. A 78 week programme is estimated for the time

needed to get feedback on each trial from customers. ENTEK would be required to conduct at least three

separate trials to gain broad customer approval. In order to continue to meet current customer demand, plant

shutdowns of a sufficient duration are only scheduled in the month of December. The total elapsed time in

this plan is estimated to be a minimum of nine years. This time frame would not be adequate if ENTEK

received any negative feedback from customers or if customers delay in their willingness to participate in the

trials. It is noted that no replacement solvent is currently commercially feasible and possible candidate

replacement solvents each pose similar or greater risks than TRI.

If ENTEK is unable to identify an alternative solvent for use in the ENTEK continuous separator

manufacturing process, ENTEK would then analyse whether a change to its process would make an

alternative solvent technically feasible. Such a change would be more significant than the process outlined

above and take significantly more engineering, procurement and construction. A temporary plant shutdown

alone as outlined above may not accommodate a commercial scale trial as required by the customers.

Depending on the process change, a longer shut down or complete plant reconstruction would be required

16

resulting in the longer term shutdown of the plant. If an alternative solvent requiring something less than

complete reconstruction of the plant could be identified, ENTEK would need at minimum of twelve years to

implement such process changes in addition to the trials required for customer approvals set forth above.

Any difficulties in implementation or negative customer reactions would result in a longer implementation

timeline.

Confidential

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2. ANALYSIS OF SUBSTANCE FUNCTION

2.1 OVERVIEW AND BACKGROUND

Entek International Ltd. is a producer of lead acid battery separators that are made of polyethylene,

precipitated silica and a process oil. Most flooded lead acid batteries use these separators. This type of

battery is used in motor vehicles to provide power for starting, lighting and ignition (SLI). Polyethylene

separators are microporous and require large amounts of precipitated silica to be sufficiently acid-wettable

(i.e., to fill the pore space in the separator and present a continuous volume of acid through the separator to

the lead plates in the battery). The volume fraction of precipitated silica and its distribution in the separator

control electrical properties, while the volume fraction and orientation of polyethylene in the separator

control mechanical properties. The porosity range for commercial polyethylene separators is 50-60%.

During the manufacture of ENTEK’s polyethylene separators, precipitated silica and ultrahigh molecular

weight polyethylene (UHMWPE) are combined with a process oil and various minor ingredients to form a

mixture that is extruded at elevated temperature to form an oil-filled sheet. The oil-filled sheet is calendered

(rolled out) to the desired thickness, and the majority of the process oil is extracted with TRI. The sheet is

then passed through a dryer and hot air oven to remove the TRI, leaving behind a microporous structure in

the separator sheet. Finally, the sheet is cut at multiple positions to form rolls of separator sheet that have the

appropriate profile for customers’ battery designs. The term “profile” refers to the width, backweb

thickness, number of ribs, rib height, and shoulder design of the separator as shown in Figure 2.1.

18

Figure 2.1. Schematic drawing of a lead-acid battery separator.

The polyethylene separator sheet is typically delivered to lead acid battery manufacturers in roll form.

The separator provides mechanical integrity for high speed enveloping and prevents sharp grid wires or

plates from shorting the battery during assembly. The separator is fed to a machine that forms ‘envelopes’

by cutting the separator material, inserting an electrode, and sealing its edges (see Figure 2.2). The electrode

is either a positive or negative grid that is pasted with electrochemically active material. Together with the

separator envelope, it forms an electrode package. The electrode package is then alternated with the other

electrode (positive or negative) type to form a stack in which the separator acts as a physical spacer and an

electronic insulator between the grids (i.e., electrodes). After making series and parallel connections

between the grids, an electrolyte (i.e., sulphuric acid) is then introduced into the assembled battery to

facilitate ionic conduction within the battery. The battery then goes through an electrochemical formation

step prior to final inspection and shipment.

Figure 2.2. Schematic drawing of a lead-acid battery and the depiction of a separator

envelope surrounding an electrode.

Shoulder Region Ribs

Shoulder Region

Backweb Backweb

19

Battery manufactures require a microporous polyethylene separators with a material composition that

provides good puncture resistance, high oxidation resistance and low electrical resistance. These

characteristics are critical for the separator to function properly both during and after formation of the

battery. UHMWPE is the material widely chosen for lead-acid battery separators because it can impart

excellent mechanical properties while serving as a “binder” for the large quantities of precipitated silica

necessary to provide wettability.

The repeat unit of polyethylene is shown below:

(-CH2CH2-)x

where x represents the average number of repeat units in an individual polymer chain. In the case of

polyethylene used in many film and molded part applications, x equals about 103-10

4 whereas for UHMWPE

x equals about 105. This difference in the number of repeat units is responsible for the higher degree of chain

entanglement and the unique properties of UHMWPE.

A specific desired property is the ability of UHMWPE to resist material flow even when heated above its

crystalline melting point (135°C). This phenomenon is a result of the long relaxation times required for

individual chains to slip past one another, and therefore, UHMWPE is not a true thermoplastic. It requires a

plasticizer such as a naphthenic process oil (as explained below) to assist in solubilizing and disentangling

the polymer chains under the high temperature and shear conditions inside a twin screw extruder. After the

extrudate passes through the die and between the calender rolls that emboss a rib pattern, the sheet is cooled

so that the oil phase separates from the polymer to form regions that will eventually become pores after

removal of the oil. There is always a controlled amount of oil left in the finished separator because it has a

positive impact upon the oxidation resistance of the separator. The residual oil is believed to reside within

the UHMWPE fibrils that are dispersed throughout the separator. In this case, the oil serves as a reactive

species for scavenging oxygen and other oxidizing agents that can attack the long polymer chains and cause

embrittlement of the separator.

The primary purpose of the hydrophilic silica is to increase the acid wettability of the separator, thereby

lowering its electrical (ionic) resistivity. In the absence of silica, the sulphuric acid would not wet the

hydrophobic polyethylene fibrils and ion transport would not occur, resulting in an inoperable battery.

Consequently, the silica component of the separator typically accounts for between 55% and 70% by weight

of the separator. Figure 2.3 shows the typical structure of a microporous separator.

20

Figure 2.3. Scanning electron micrograph showing the morphology of an ENTEK Pb-acid

battery separator.

2.2 MANUFACTURE OF POLYETHYLENE-BASED SEPARATORS - PROCESS

DESCRIPTION

An overview of the ENTEK separator manufacturing process to make polyethylene separators is illustrated

in Figure 2.4. This represents a very simple schematic of a single production line. For a more

comprehensive description of ENTEK’s separator manufacturing process, including the solvent extraction

and recovery process, refer to Figure 2.5.

21

Mix preparationFiller - silciapolyethyleneProcess oil

Extrusion(formation of sheet)

Drying (steam)(removal of TRI)

Extraction(of oil with TRI)

Hot air oven(removal of TRI)

Winding and slitting(finished separator rolls)

Calendering(formation of sheet)

Figure 2.4. Simple schematic of the ENTEK separator manufacturing process, showing a single processing line.

22

Figure 2.5. Comprehensive schematic of the ENTEK separator manufacturing process, showing solvent extraction and recovery loops.

23

A critical step in the manufacturing process is the extraction of a controlled amount of process oil from the

sheet and subsequent removal of the extraction solvent to form a microporous separator. ENTEK uses the

Annex XIV substance TRI as its extraction solvent. The purpose and function of the TRI in this use is to

perform the extraction of process oil by displacing the majority of the oil in the sheet. This is followed by

evaporation of the TRI to leave behind interconnected pores in the finished separator.

There are seven critical requirements for an extraction solvent (as fulfilled by TRI) in the ENTEK

manufacturing process:

1. Non-flammability.

2. Miscibility with a process oil that is a plasticizer for UHMWPE.

3. Recoverable in high purity via distillation of oil/solvent mixtures.

4. High affinity for activated carbon to promote vapour recovery.

5. Minimal solubility in water.

6. A low health and safety risk when exposure is managed within accepted limits.

7. Chemical stability under the conditions used for extraction, drying and recovery.

In the ENTEK process, TRI is recovered by distillation of the oil-TRI mixture that results from extraction of

the sheet. Trichloroethylene is also recovered during the drying step, as both a liquid that has been

condensed from the steam-TRI mixture in the dryer and as a vapour that is adsorbed in a carbon bed recovery

system (see Figure 2.5). Based on the critical requirements for an extraction solvent as set forth above, the

following selection criteria were developed to analyze potential alternatives.

Following are the primary selection criteria for an extraction solvent in the ENTEK process:

1. Hazard rating: non-flammable.

2. High degree of solvency for the process oil.

3. Reasonable vapour pressure for effective evaporation.

4. Low surface tension to prevent pore collapse due to capillary forces exerted during evaporation of

the solvent from the sheet.

5. Condensable in a steam atmosphere.

6. Minimal solubility in water.

7. Reversible recovery of high purity solvent using distillation and vapour adsorption/desorption onto

activated carbon in a continuous process.

8. Low environmental, health, and safety risk when exposure is managed within acceptable limits.

9. Chemical stability under the conditions used for extraction, drying, and recovery.

10. Available in required quantity at reasonable cost.

11. A finished separator that meets customer requirements for battery production and performance.

24

These selection criteria have guided ENTEK’s choice of TRI as its extraction solvent. First and foremost,

ENTEK believes that it is prudent to use a non-flammable solvent to ensure the safety of its workforce and

capital investment. The use of any flammable solvent is not compatible with ENTEK’s continuous separator

manufacturing process (raw materials to finished separator rolls). The requirement for a non-flammable

solvent quickly consolidates the potential solvent options.

A high degree of solvency for the ENTEK process oil is important because it ultimately determines the

residence time that is required in the extractor. The solvent also needs to have a vapour pressure that is

compatible with recovery in distillation and drying steps.

In the ENTEK process, the TRI is evaporated from the sheet with steam in the dryer. The ability to utilize

steam is beneficial because a condensable atmosphere can be created such that cooling coils at the bottom of

the dryer can be utilized to condense a large portion of the TRI as a liquid mixed with water. The phase

separation of the TRI/water mixture is readily accomplished, and a reduced amount of TRI vapour is sent to

carbon beds for recovery. This is a much less energy intensive option as compared to using hot air to

evaporate the TRI from the separator sheet and then sending 100% of it to the carbon beds in vapour form.

Finally, solvent cost and availability are important to ensure that the ENTEK separator manufacturing

process remains profitable.

2.3 CONSIDERATION OF OBSTACLES OR DIFFICULTIES IDENTIFIED OR

EXPECTED IN RELATION TO FINDING AN ALTERNATIVE FULFILLING OR

REPLACING THE EQUIVALENT FUNCTION OF TRI.

The guidance in the analysis of alternative template document from ECHA requests the applicant to “Present

the list of essential criteria for fulfilling the substance function that served as the basis for the assessment of

the alternatives. Justify why these criteria are the most relevant for the selection of the possible alternatives

by linking the criteria to the function, tasks and conditions under which the substance is used in the specific

use applied for”. The functions of TRI as a process solvent for the extraction of process oil from

polyethylene sheet are set out above. Table 2.1 below is a summary of the essential criteria with a short

explanation/comment to justify why that is the case; however, the detailed arguments are set out in the

subsequent sections. The table also takes account of the checklist for Annex XIV Substance Function

suggested in the ECHA Guidance on Authorisation Applications.

25

Table 2.1 Summary of essential criteria for substance function

Essential criterion for

substance function

Justification/explanation

1. Task performed by Annex

XIV substance

TRI is used to remove (extract) naphthenic process oil from polyethylene/silica sheet during the manufacture of battery

separators for onward use in lead acid batteries in automobiles. The use of TRI maintains fire and explosion safety in

ENTEK’s continuous manufacturing process. It also enables effective recovery and reuse of TRI by distillation or

carbon adsorption/desorption.

Lead acid battery separators are primarily composed of UHMWPE, precipitated silica and oil. UHMWPE is a unique

polymer that requires a large percentage of process oil to be extruded in sheet form. This polymer imparts the necessary

mechanical properties for handling in the manufacturing process. It also imparts high puncture strength demanded by customers.

There is significantly less oil in the finished product than the amount of oil required for manufacturing separators;

therefore, a solvent is required to remove the majority of the oil from the extruded sheet. After removal of the required

amount of oil, the solvent must then be evaporated from the sheet. This step leaves behind the required amount of porosity to enable ion transport in a battery.

The solvent must be highly miscible with the process oil and nonflammable in the ENTEK continuous separator

manufacturing process. After removal of the process oil the oil/solvent mixture must be distilled into its separate components for reuse in the manufacturing process.

The solvent is also recaptured after evaporation from the separator sheet in both vapour and liquid form. The vapour is

recovered through adsorption/desorption in a carbon bed system and the liquid is phase separated from the condensed steam/solvent mixture formed in the dryer.

2. What critical properties

and quality criteria must the

substance fulfill?

Non-flammability

A non-flammable solvent is critical to worker and equipment safety. Additionally, this characteristic makes it

compatible with the ENTEK continuous manufacturing process.

A high degree of solvency with process oil

The solvent must have a high degree of solvency for the process oil so that the oil can be extracted efficiently.

Reasonable vapour pressure

for effective evaporation

The vapour pressure determines the ability of the solvent to be evaporated and recovered from the continuous process,

enabling recycling of the substance.

26

Condensable in a steam

atmosphere

A reversible recovery of

solvent using distillation and

high surface area carbon

The recovery processes require a solvent that can be condensed in a steam atmosphere and that can be captured on

carbon and subsequently released and recovered.

3. Function conditions

Ambient/room temperature

processing

Effective extraction of oil from the sheet in closed solvent baths allows efficient use of energy and control and capture of

solvent vapour. The recovery of process oil is accomplished through distillation of the oil TRI mixture removed from the extractors.

Recovery of process solvent

and process oil

TRI is recovered in both vapour and liquid form at different points in the manufacturing process. Liquid TRI is

recovered via distillation of the oil/TRI mixture and from phase separation of the water/TRI mixture condensed during

the drying stage. Finally, TRI vapour is recovered through adsorption/desorption in the carbon beds. The recovered TRI is then reused in the ENTEK continuous separator manufacturing process.

4. Process and performance constraints

Product

Upon evaporation of the solvent, the finished separator must have sufficient porosity and wettability to provide low

electrical (ionic) resistance.

Performance of the separator

in lead acid batteries and

acceptance of product by

customers.

It is essential that the separator provides mechanical integrity so that the separator can be enveloped at high speeds and to

prevent grid wire puncture during battery assembly or operation. It is also essential that any trace amount of the solvent left in the separator will not negatively affect the electrochemical performance of the lead acid batteries.

Compatibility with the

process equipment for

making polyethylene separators.

TRI is stable and nonreactive with the grade of Stainless Steel used throughout the ENTEK plant for equipment that

handles solvent (e.g. piping, valves, fittings, carbon beds, extractor and dryer).

27

5. Is the function associated

with another process that

could be altered so that the

use of the substance is

limited or eliminated?

There are two main processes involving TRI:

3) The extraction of process oil from the separator sheet to reduce the oil content from about 65% by weight to

about 15% by weight in the finished product.

4) The recovery and recycling of the TRI that allows reuse of the solvent with a high degree of efficiency.

Both processes allow battery separators to be manufactured efficiently in a continuous process with good control of

releases.

Both processes are interdependent and specifically designed for the use of TRI. The possibilities for using an alternative

substance are analysed and the associated process changes considered in this document. It is found that it is not currently

possible for the applicant to use an alternative. Research concludes that it will be at least 12 years before an alternative

could be commercially acceptable.

6. What customer

requirements affect the use of the substance in this use?

Key separator characteristics

The lead-acid storage battery includes positive and negative electrodes that are separated from each other by a porous

battery separator. There are five major requirements for the battery separator, it must:

1) be an electrical insulator to prevent shorting between the electrodes;

2) be composed of materials that can provide chemical and oxidation resistance;

3) be porous to allow for ionic conduction through the separator as the battery is discharged;

4) provide the correct mechanical spacing and electrolyte volume between the electrodes; and

5) run effectively through the separator enveloping line during battery manufacture.

TRI enables the above key separator characteristics by:

controlled quantitative removal of process oil from the extruded separator sheet;

evaporation of solvent from the separator sheet to leave behind the required pore size distribution and percent porosity;

not negatively impacting battery performance even if trace amounts of residual solvent remain in the finished

product; and

closed loop recycling allows for safe reuse of the solvent in the manufacturing process and delivery of the separator to the customer at a competitive price.

28

Security of supply

Separators are a critical component in lead acid batteries used throughout Europe. Security of supply is of critical

importance for battery manufacturers. Each supply location plays a critical role in the security of supply for the battery

manufacturers. Each supplier is expected to have robust processes to ensure timely delivery of this critical component.

For example, annual analysis and reporting on risks to continuous operation and mitigation efforts for these risks, for

example, fire safety, may be contractually required.

7. Are there particular

industry sector requirements

or legal requirements for

technical acceptability that

must be met and that the function must deliver?

Battery Council International (BCI), Society of Automotive Engineers (SAE), and European Norm (EN) specifications

must be met for both separators and lead-acid batteries.

29

Section 4 below sets out the research, development, and engineering undertaken by ENTEK to identify and

investigate potential alternatives. Section 6 considers the steps needed to phase in potential alternatives

including the technical and commercial barriers that must be overcome.

30

3 ANNUAL TONNAGE

The applied for tonnage is within the tonnage band 10-100 tonnes per year.

31

4 IDENTIFICATION OF POSSIBLE ALTERNATIVES

4.1 LIST OF POSSIBLE ALTERNATIVES

As described in Section 2, the function of the Annex XIV substance (TRI or TCE) in the manufacture of

polyethylene separators for lead-acid batteries is as a solvent to extract process oil from the sheet in required

to impart specific qualities to the sheet. In addition, the choice of solvent allows effective extraction

recovery and recycling of solvent. This identification of possible alternatives therefore focuses on possible

solvents that could be suitable for replacement of TRI and their compatibility with the ENTEK continuous

separator manufacturing process and end-product. There are other separator technologies available that are

currently available (i.e., it is possible to use separators in lead acid batteries that are not polyethylene based,

see section 4.2.2). While the substance function does not direct the investigation of these technical

alternatives, the need for consideration of them is acknowledged, as this analysis should be in line with the

non-use scenario set out in the Socio Economic Analysis (SEA), which considers what the response would

be should polyethylene separators made using TRI not be available.

ENTEK scientists and engineers with detailed knowledge of the ENTEK continuous separator manufacturing

process have investigated possible alternatives to TRI. The list of possible substance alternatives was

identified as follows:

1. n-Hexane

2. Dichloromethane (methylene chloride)

3. Tetrachloroethylene (perchloroethylene)

4. Vertrel® SDG - an engineered mixture of non-flammable hydrofluorocarbons (HFCs) and trans-1,2-

dichloroethylene (t-DCE).

5. HFE 72DE trans-1,2-dichloroethylene CAS 156-60-5 (68 – 72%); ethyl nonafluoroisobutyl ether

CAS 163702-06-5 (4 – 16%); ethyl nonafluorobutyl ether CAS 163702-05-4 (4 – 16%); methyl

nonafluoroisobutyl ether CAS 163702-08-7 (2 – 8%); methyl nonafluorobutyl ether CAS 163702-

07-6 (2 – 8%)

6. n-Propyl bromide (1-bromopropane)

7. D-Limonene

8. Acetone

Other solvents (such as 1,2–dichloroethylene, alcohols (e.g. propan-2-ol and n-butanol) and siloxanes (such

as octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5)) and approaches to extraction

were considered, but eliminated because of chemical or equipment incompatibilities. For example, water

32

cannot be used as the extraction solvent since it is not miscible with the process oil. Additionally, while

supercritical carbon dioxide can be used as an extraction solvent for certain applications (e.g., decaffeination

of coffee beans), it requires a closed pressure vessel and is not a viable option in the ENTEK separator

manufacturing process because it is not possible to use this in a continuous process.

Table 4.1 below sets out a list of possible substance alternatives, which was a starting point for research on

possible replacement substances in the ENTEK continuous separator manufacturing process. Key

physicochemical properties as well as classification and labelling requirements in the EU are key

considerations for technical feasibility and hazards profile. In addition, consideration is given to the status of

substances under the REACH Regulation to give an initial indication of availability and regulatory status.

33

Table 4.1 Possible TRI alternatives in the ENTEK continuous separator manufacturing process (based on information from ENTEK

and other sources), TRI data is presented for reference.

Substance name CAS Boiling

Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)

Comments and risk phrases/hazard

statements

Trichloroethylene 79-01-6 87 263 N/A/

420

8 / 12.5 Carc. Cat. 2; R45

- Muta. Cat. 3;

R68 - R67 -

Xi; R36/38 -

R52-53

GHS

Skin Irrit. 2 H315

Eye Irrit. 2 H319

STOT SE 3 H336

Muta. 2 H341

Carc. 1B H350

Aquatic Chronic

3 H412

Registered

under

REACH

phase 1

Current solvent. Subject to EU risk assessment

under ESR, Reach Registration done by Dow

LR. Possible placing on Carcinogens and

Mutagens Directive (with bOEL), current iOEL

10ppm (8hr TWA)

H315 Causes skin irritation

H319 Causes serious eye irritation

H336 May cause drowsiness or dizziness

H341 Suspected of causing genetic defects

H350 May cause cancer

H412 Harmful to aquatic life with long lasting

effects

n-Hexane 110-54-3 68 335 -23/224 1.2 / 7.7 F; R11 -

Repr. Cat. 3; R62

- Xn; R65-48/20

- Xi; R38 -

R67 - N; R51-

53

GHS

Flam. Liq. 2

H225

Asp. Tox. 1 H304

Registered

under

REACH

phase 1

Being

considered

under the

CoRAP

(2012 – on

going)

grounds for

+ R11 : Highly flammable.

+ R48/20 : Harmful: danger of serious damage

to health by prolonged exposure through

inhalation.

+ R62 : Possible risk of impaired fertility.

+ R51/53 : Toxic to aquatic organisms, may

cause long-term adverse effects in the aquatic

environment.

H225 – Highly flammable liquid and vapour

34


Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)


statements

Skin Irrit. 2 H315

STOT SE 3 H336

Repr. 2 H361f

STOT RE 2 H373

Aquatic Chronic

2 H411

concern:

Human

health/CMR

and

neurotoxicity

;

Exposure/Wi

de dispersive

use, high

aggregated

tonnage

H304 May be fatal if swallowed and enters

airways.



H361f Suspected of damaging fertility

H373 May cause damage to organs

Affected organs: nervous system

Route of exposure: Inhalation

H411 Toxic to aquatic life with long lasting

effects

Methylene

chloride

(dichloromethane

)

75-09-2 40 329 N/A

/556

12 / 23 Carc. Cat. 3; R40

GHS

Carc. 2 H351

Self-

classification:

Skin Irrit. 2

H315.

Eye Irrit. 2 H319:

STOT Single

Exp. 3 H336:

Registered

under

REACH

phase 1.

+ R40 : Limited evidence of a carcinogenic

effect.

H351: Suspected of causing cancer.

Self-classification:

H315: Causes skin irritation. H319: Causes

serious eye irritation.

H336: May cause drowsiness or dizziness.

Affected organs: central nervous system


Tetrachloroethyle

ne

(perchloroethylen

e)

127-18-4 121 209 N/A/N/

A

N/A/N/A Carc. Cat. 3; R40

- N; R51-53

GHS:

Registered

under

REACH

phase 1.

+ R40 : Limited evidence of a carcinogenic

effect.

+ R51/53 : Toxic to aquatic organisms, may

35


Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)


statements

Carc. 2 H351

Aquatic Chronic

2 H411

Self-

classification:

Skin Irrit. 2 H315

Eye Irrit. 2 H319:

Skin Sens. 1B

H317.

STOT Single

Exp. 3 H336:

Considered

under the

CoRAP

(2013 – on

going)

grounds for

concern:

Human

health/CMR;

Environment

/Suspected

PBT;

Exposure/Wi

de dispersive

use;

Aggregated

tonnage:


environment.

H351: Suspected of causing cancer.

H411: Toxic to aquatic life with long lasting

effects.

CoRAP completed with final decision provided

in July 2014: no further data needs identified.

‘Concern clarified; No need of further risk

management measures’

Self-classification:

H315: Causes skin irritation.

H319: Causes serious eye irritation.

H317: May cause an allergic skin reaction.

H336: May cause drowsiness or dizziness.



Vertrel® SDG N/A 43 N/A no

flashpo

int /

N/A

7 / 14 No harmonised

classification is

available for the

mixture. The

constituent trans-

dichloroethylene

CAS 156-60-5

(65-90%) has the

following

harmonised

classification:

Constituent

CAS

138495-42-8

(5-25%) has

been

registered

under

REACH

phase not

determined.

Constituent

For trans-dichloroethylene CAS 156-60-5:

+ R11 : Highly flammable

+ R20: Harmful by inhalation

+ R52/53 : Harmful to aquatic organisms, may


environment.

H225: Highly flammable liquid and vapour

H332: Harmful if inhaled

H411: Harmful to aquatic life with long lasting

36


Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)


statements

F; R11 - Xn;

R20 - R52/53

GHS

Flam. Liq. 2 -

H225

Acute Tox 4 -

H332, Aquatic

Chronic 3 – H412

CAS 15290-

77-4 (5-

15%) has a

NONS

registration

as a polymer

effects.

HFE 72DE trans-

1,2-

dichloroethylene

N/A 45 N/A N/A /

396

6.7 / 13.7 No harmonised

classification is

available for the

mixture. The

constituent trans-

dichloroethylene

CAS 156-60-5

(65-90%) has the

following

harmonised

classification:

F; R11 - Xn;

R20 - R52/53

GHS

Flam. Liq. 2 -

H225

Acute Tox 4 -

H332

Aquatic Chronic

3 – H412

Constituent

CAS

138495-42-8

(5-25%) has

been

registered

under

REACH

phase not

determined.

For trans-dichloroethylene, CAS 156-60-5:

+ R11 : Highly flammable

+ R20: Harmful by inhalation



environment.

H225: Highly flammable liquid and vapour

H332: Harmful if inhaled

H411: Harmful to aquatic life with long lasting

effects.

n-Propyl Bromide 106-94-5 71 243 22/490 4.6 / - F; R11 - Repr. Registered New data indicating have been published

37


Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)


statements

(1-

bromopropane)

Cat. 2; R60 -

Repr. Cat. 3; R63

- Xn; R48/20 -

Xi; R36/37/38 -

R67

GHS

Flam. Liq. 2

H225

Skin Irrit. 2 H315

Eye Irrit. 2 H319

STOT SE 3 H335

STOT SE 3 H336

Repr. 1B H360FD

STOT RE 2 H373

under

REACH

phase 1.

Substance of

very high

concern

(SVHC) on

the basis of

toxicity to

reproduction

and listed on

the REACH

Candidate

list for

Authorisatio

n

indicating neurotoxic effects in workers exposed

to low levels on nPB—ACGIH decreased the

TLV to 0.1 ppm in response; OSHA issued an

alert.

+ R60 : May impair fertility.


+ R36/37/38 : Irritating to eyes, respiratory

system and skin.

+ R48/20 : Harmful: danger of serious damage

to health by prolonged exposure through

inhalation.

+ R63 : Possible risk of harm to the unborn

child.




H335 May cause respiratory irritation


H360FD. May damage fertility. May damage

the unborn child.

H373 May cause damage to organs

(R)-p-mentha-

1,8-diene

D-Limonene

5989-27-

5 R10

Xi; R38

R43

N; R50-53

GHS

Registered

under

REACH

phase 1.

R10 – Flammable

R38 – Irritating to skin

R43 – May cause sensitization by skin contact

R50-53 – Very toxic to aquatic organism, may

cause long term adverse effects in the aquatic

38


Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)


statements

Flam. Liq. 3

H226

Skin Irrit. 2 H315

Skin Sens. 1

H317

Aquatic Acute 1

H400

Aquatic Chronic

1 H410

environment.

H226 – Flammable liquid and vapour


H317 May cause and allergic skin reaction

H400 – Very toxic to aquatic life

H410 – Very toxic to aquatic life with long

lasting effects.

Acetone

(representative of

various ketones)

67-64-1 57 525 -20/465 2.5 / 12.8 F; R11 - Xi;

R36 - R66 -

R67

GHS

Flam. Liq. 2

H225

Eye Irrit. 2 H319

STOT SE 3 H336

Registered

under

REACH

phase 1.


+ R36 : Irritating to eyes.

+ R66: Repeated exposure may cause skin

dryness or cracking

+ R67: Vapours may cause drowsiness and

diziness




1,2-

Dichloroethylene

540-59-0 60.1 305.4 2/ 460 5.6/12/8 F; R11 - Xn;

R20 - R52-53

Flam. Liq. 2

H225

Acute Tox. 4*

H332

Aquatic Chronic

Not yet

registered

under

REACH


+ R20 : Harmful by inhalation.



environment.


H332 – Harmful if inhaled

39


Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)


statements

3 H412 H412 Harmful to aquatic life with long lasting

effects

Examples of alcohols

Propan-2-ol 67-63-0 82 45.39 12/399 2.0/12.7 F; R11 - Xi;

R36 - R67

GHS

Flam. Liq. 2 H225

Eye Irrit. 2 H319

STOT SE 3 H336

Registered

under

REACH

phase 1.


+ R36 : Irritating to eyes.


diziness


H319 – Causes serious eye irritation

H336 – May cause drowsiness or dizziness

n-Butanol 71-36-3 117.7 52.35 37/343 1.4 / 11.2 R10 – Xn; R22 –

Xi; R37/38-41 –

R67

GHS

Flam. Liq. 3

Acute Tox – 4

Skin irrit. 2

Eye Dam. 1

STOT SE 3 H335

STOT SE 3 H336

Registered

under

REACH

phase 1.

+ R10 : Flammable.

+ R22: Harmful if swallowed

+ R37/38 : Irritating to respiratory system and

skin.

+ R41: Risk of serious damage to eyes


diziness

H226 – Flammable liquid and vapour

H302 – Harmful if swallowed

H315 – Causes skin irritation

H318 – Causes serious eye damage

H335 – May cause respiratory irritation

H336 – May cause serious drowsiness or

dizziness

40


Point

(oC)

Heat of

Vaporisation

(kJ/kg)

Flash

Point

/auto

ignitio

n temp

(oC)

Flamma

bility

limits

(%)

Classification

(EU dangerous

substances

directive and

CLP/GHS)1

Regulatory

Status (EU)


statements

Octamethylcyclot

etrasiloxane (D4)

556-67-2 175 N/A 51-55 /

N/A

0.75 / 7.4 Repr. Cat. 3; R62

- R53

GHS

Repr. 2 H361f

Aquatic Chronic 4

H413

Registered

under

REACH

phase 1

R53 : May cause long-term adverse effects in

the aquatic environment.

+ R62 : Possible risk of impaired fertility.

H361f Suspected of damaging fertility

H413 May cause long lasting harmful effects to

aquatic life.

Decamethylcyclo

pentasiloxane

(D5)

541-02-6 210 N/A 51-55/

N/A

0.45 /

13.21

GHS (not

harmonised,

summary of all

proposals)

Aquatic Chronic 4

H413

Eye Irrit. 2 H319

Acute Tox. 3

H331

Skin Irrit. 2 H315

STOT SE 3 H335

Registered

under

REACH

phase 1

H413 May cause long lasting harmful effects to

aquatic life.

H319 – Causes serious eye irritation

H341 – Toxic if inhaled

H315 – Causes skin irritation

H335 – May cause respiratory irritation

Notes: 1 Classifications are harmonized unless indicated otherwise.

41

4.2 DESCRIPTION OF EFFORTS MADE TO IDENTIFY POSSIBLE

ALTERNATIVES

The alternative solvents listed above (see Table 3.1 below) were evaluated in the ENTEK R&D laboratory as

noted. Initial experiments involved collecting an oil-filled precursor polyethylene sheet from an ENTEK

production line. The oil-filled sheet was then cut into ~ 160 mm x ~160 mm pieces that were individually

placed in the alternative solvents for various time periods to evaluate extraction rates and efficiency. The

solvent-laden sheets were then dried in air and the resultant separator properties were evaluated. The major

characterization data that were collected from these laboratory experiments included:

Solubility of ENTEK process oil in each alternative solvent

Rate of process oil extraction for each alternative solvent

Shrinkage of solvent-laden separator upon drying

Impact of trace solvent in the separator on lead acid electrochemistry

Separator porosity

Separator electrical (ionic) resistance

Separator mechanical properties

In the case of dichloromethane (DCM), additional work was done on rolls of oil-filled precursor sheet that

were passed through a portable extractor-dryer unit to more closely mimic the ENTEK separator

manufacturing process. The DCM-dried separator was then compared to separator dried from TRI using the

same portable extractor-dryer unit.

It should be noted that in all cases, the laboratory and portable extractor-dryer experiments only give a partial

answer in regard to the feasibility of an alternative solvent. Full scale production trials are required before

any definitive decision can be made regarding the commercial feasibility of an alternative solvent. This is

necessary to ensure that expected throughputs can be met on existing equipment and that the final separator

properties and roll characteristics meet specification. Furthermore, closed loop recovery of any alternative

solvent must be demonstrated via distillation and vapour adsorption/desorption in carbon beds. Such large

scale trials would also be required by battery manufacturers attempting to qualify any new separator or

change to the separator manufacturing process with their OEM (original equipment manufacturer) customers

(see Section 5).

It is difficult to perform such trials at the ENTEK plant because the carbon bed, oil recirculation, and water

recovery systems for the four production lines are coupled together forming a highly integrated continuous

42

process system. Isolating a single production line to carry out a scaled production trial with an alternative

solvent would reduce the capacity of the plant serving current customers and require the duplication of

solvent and oil recovery systems in addition to specifying, ordering and installing specialty equipment. As

such, due to existing separator demand from the ENTEK plant, the only opportunity for such experiments to

be performed is during the annual shutdown period that takes place two weeks in December (see Section 5

for the REACH Solvent Conversion Plan).

4.2.1 Research and Development

Confidential

4.2.1.1 Solvent Alternatives

Table 4.2 lists the physico-chemical properties of TRI and other alternative solvents that have been

investigated by ENTEK. The human health and environmental classifications for each solvent are addressed

individually in a later portion of this analysis report.

43

Table 4.2 Key physicochemical properties of possible alternatives in comparison to TRI

Solvent CAS Boiling

point

(oC)

Density

(g/ml)

Vapour

Pressure

at 25oC

(mm Hg)

Viscosity at

25oC (cps)

Surface

Tension, 25oC

(dynes/cm)

Heat of

vaporisatio

n (cal/g)

Flash

Point

closed cup

(oC)

Solubility

in water

(25oC)

(g/100cc)

Initially

tested by

ENTEK

Trichloroethylene 79-01-6 87 1.44 74 0.54 32.3 56.4 None 0.11 Yes

n-Hexane 110-54-3 69 0.65 150 0.32 17.9 79.9 -22 0.00095 Yes

Dichloromethane

(DCM)

75-09-2 40 1.33 350 0.44 28.1 75.3 None 1.3 Yes

Tetrachloroethyle

ne

127-18-4 121 1.62 18 0.75 29.5 50.1 None 0.015 Yes

Vertrel SDG 43 1.29 388 0.59 21.2 67.1 None 0.95 Yes

HFE 72DE 43 1.28 350 0.45 19 52 None 0.001 Yes

n-Propyl bromide 106-94-5 71 1.35 150 0.49 25.9 58.8 21 0.23 Yes

D-Limonene 5989-27-

5

176 0.84 1.4 1.28 25 84.3 48 0.00138 Yes

Acetone 67-64-1 56 0.78 230 0.4 23.7 120 -20 infinite Yes

1,2

Dichloroethylene

156-59-2 60.2 1.28 200 0.48 0.0028 305.4 2.2-3.9 3.5-

6.4E+03

No

Propan-2-ol 67-63-0 82 0.76 45.4 2.04 20.9 45.39 12 soluble No

n-Butanol 71-36-3 117 0.81 7.0 2.5 24.9 52.35 37 soluble No

D4 (siloxane) 556-67-2 175 0.95 1.18 2.4-2.7 N/A N/A 51-55 300000 No

D5 (siloxane) 541-02-6 210 0.96 0.174 3.5 N/A N/A 82.7 0.017 No

44

Solvency and Extraction Rate

The solubility of the alternative solvents with process oil (as used in the ENTEK separator manufacturing

process) was first estimated using Hansen solubility parameters from the literature. It should be noted that

no values were available for Vertrel® SDG.

‘Hansen Solubility Parameters’ (HSPs) are a set of parameters devised by Charles M. Hansen that determine

if any two compounds will dissolve into each other. The first parameter is δD which is a measure of

dispersion or Van Der Waals forces. The second parameter is δP which measures the energy related to polar

interactions and finally δH is a measure of energy resulting from hydrogen bonds. This allows a calculation

of whether two solvents will dissolve. These three parameters combined with the interaction radius of the

species being dissolved can determine whether a solvent will dissolve the compound in question.

The Hansen solubility parameters for the solvents were calculated based upon their thermodynamic

properties as defined below:

Ra2 = 4(δD1 – δD2)² + (δP1 – δP2)² + (δH1 – δH2)²

δ: partial/Hansen solubility parameter

D, P, H: dispersion, polar, and hydrogen bonding components of the solubility parameter

1 denotes solvent, 2 denotes oil

Ra: solubility parameter distance in the Hansen solubility space

Minimization of Ra is desired

RED = Ra/R0

R0: Solubility sphere of the oil, centred at (δD2, δP2, δH2)

R0 is determined experimentally

Solubility occurs when the distance Ra lies within the sphere: RED number <1

Solvency of oil in a solvent is higher as R0 approaches zero.

45

The Hansen solubility parameters for the naphthenic process oil used in the ENTEK continuous separator

manufacturing process were estimated from the work of Levin and Redelius (Energy & Fuels 2008; vol. 22,

issue 5, pp. 3395-3401).

Table 4.2 lists the relevant Hansen solubility parameters and the RED value that was calculated for each

alternative solvent and its interaction with a naphthenic process oil. In the case of acetone, the RED value is

greater than 1, indicating that it is a relatively poor solvent for the oil. All other solvents show strong

interaction with oil.

Table 4.2 Comparative Hansen solubility parameters

Solvent δ D(MPa)0.5 δ p(MPa)

0.5 δ H(MPa)0.5 Ra

2 Ra RED

n- Hexane 14.9 0 0 18.8 4.3 0.4

HFE 72 de 16.3 6.9 2.5 52.3 7.2 0.7

Dichloromethane 18.2 6.3 6.1 70.7 8.4 0.8

Trichloroethylene 18 3.1 5.3 34.1 5.8 0.6

n-Propylbromide 16.4 7.9 4.8 65.5 8.1 0.8

Tetrachloroethylene 18.3 5.7 0 78.5 8.9 0.9

D-Limonene 16.6 0.6 0 21.2 4.9 0.5

Acetone 15.5 10.4 7 116.6 10.8 1.1

In addition to the above calculations, ENTEK also performed laboratory experiments to evaluate the

extraction rate using the alternative solvents. These experiments were performed on oil-filled precursor

sheets obtained from a separator production line. The extraction was performed at room temperature with an

excess amount of solvent under agitation in a large beaker. Samples were removed after certain time

periods, dried, and then weighed to determine the amount of oil that had been extracted. The experiment was

repeated three different times for each solvent.

Figure 4.1 shows the results of the extraction experiment. The dashed line represents a residual oil value of

15 wt. % which is the target value for ENTEK separator production. It is clear from the data that acetone

cannot be used as the extraction solvent as was predicted from the Hansen solubility calculations. Compared

to TRI, samples extracted with tetrachloroethylene or D-limonene have higher residual oil contents for a

given extraction time. These data indicate that both solvents are less efficient at oil extraction than TRI.

While they still might be viable in a production process, ENTEK would be forced to slow down its

production lines, increase the length of its extractors, or heat the alternative solvent to an elevated

temperature in its extractors.

Although Hansen solubility parameters were not available for Vertrel® SDG, the extraction data show that

both it and hexane actually exhibit faster extraction rates than TRI. Based upon the extraction rate data,

46

diffusion coefficients were calculated from the slope of the lines shown in Figure 3.2 for each alternative

solvent. A relative diffusion coefficient ratio was then calculated from the slope for each solvent divided by

the TRI slope. Table 3.3 shows that n-hexane, Vertrel® SDG, HFE 72 DE, and dichloromethane would all

provide faster oil extraction compared to TRI. Significantly longer extraction times were exhibited by n-

propyl bromide, tetrachloroethylene and D-limonene. Finally, acetone can be eliminated as a potential

alternative solvent based upon its slow extraction rate for naphthenic process oil.

Oil Filled Flatsheet Extraction: Room Temperature

0%

10%

20%

30%

40%

50%

60%

70%

0 10 20 30 40 50 60 70 80 90 100

Time (sec.)

Resid

ual O

il C

on

ten

t

DCM Acetone n-Hexane Tetra-CE nPB HFE 72DE D-Limonene Vertrel SDG Tri-CE

Figure 4.1. Residual oil content vs. time for various extraction solvents.

Oil Filled Flatsheet Extraction: Room Temperature

0.001

0.010

0.100

1.000

0 10 20 30 40 50 60 70 80 90 100

Time (sec.)

Dim

en

sio

nle

ss C

on

ce

ntr

ati

on

, C

/C0

DCM Acetone n-Hexane Tetra-CE nPB HFE 72DE D-Limonene Vertrel SDG Tri-CE

Figure 4.2. Dimensionless concentration vs time for various extraction solvents.

47

Table 4.3 Rates of oil extraction compared to TRI

Solvent

Slope of ln(C/C0)

vs. Time

Relative Diffusion

Coefficient Ratio vs. TCE

Viscosity, 25°C

(cps) RED

n-Hexane 0.1170 0.67 0.32 0.4

Vertrel SDG 0.0962 0.82 0.59 NA

HFE 72DE 0.0877 0.90 0.45 0.7

Dichloromethane (DCM) 0.0866 0.91 0.44 0.8

Trichloroethylene (Tri-CE) 0.0789 1.00 0.54 0.6

n-propylbromide (nPB) 0.0748 1.05 0.49 0.8

Tetrachloroethylene (Tetra-CE) 0.0525 1.50 0.75 0.9

R-(+)-Limonene (D-Limonene) 0.0452 1.75 1.28 0.5

Acetone 0.0105 7.51 0.40 1.1

Drying

Once the oil has been extracted to its target level, the solvent-laden sheet then passes into the dryer. In the

ENTEK drying process, steam is used to evaporate the solvent from the sheet. In the laboratory experiments,

the solvent-laden sheets were simply dried in an oven to determine the amount of shrinkage in all three

dimensions. As the solvent is evaporated from the sheet, capillary forces are exerted on the pore walls.

The capillary force depends upon surface tension of the solvent, the contact angle, and the pore radius as

shown in the following equation:

Pc = (- 2 LV cos ) / r

where Pc equals capillary pressure, LV is surface tension at the liquid-vapour interface, is the

contact angle, and r equals pore radius.

Such capillary forces can lead to the collapse or compaction of the pores, resulting in dimensional shrinkage

and smaller pore size distribution in the finished separator. The capillary force is governed by the surface

tension of the extraction solvent – the higher the surface tension, the higher the capillary force, and thus the

higher the separator shrinkage.

Table 4.4 shows the surface tension of the alternative solvents along with the measured separator shrinkage.

48

Table 4.4 Shrinkage of polyethylene sheet on drying compared to TRI

Solvent

Surface Tension,

25°C (dynes/cm)

MD Shrinkage

(%)

CMD Shrinkage

(%)

Thickness

Shrinkage (%)

Relative Volume

after Shrinkage

n-Hexane 17.9 6.9 2.7 1.0 0.90

Vertrel SDG 21.2 6.8 2.5 1.5 0.89

HFE 72DE 19 6.8 2.2 0.5 0.91

Dichloromethane (DCM) 28.1 7.7 3.8 1.7 0.87

Trichloroethylene (Tri-CE) 32.3 11.0 5.7 5.0 0.80

n-propylbromide (nPB) 25.9 9.8 4.5 2.2 0.84

Tetrachloroethylene (Tetra-CE) 29.5 14.4 8.1 3.9 0.76

R-(+)-Limonene (D-Limonene) 25 16.8 8.2 6.3 0.72

Acetone 23.7 12.5 6.3 5.0 0.78

Separator shrinkage is important because it affects the final separator properties such as porosity, pore size

distribution, and also enables ENTEK to determine if the same calender rolls (that impart the rib pattern to

the oil-filled sheet) can be utilized to achieve the same final separator profile. From the data, it is clear that

solvents such as n-hexane, Vertrel® SDG, HFE 72DE, and dichloromethane result in less separator shrinkage

than when the drying is done from TRI. While this would result in higher porosity that may be beneficial to

separator electrical resistance, it means that the final separator profile (rib spacing, shoulder width, thickness)

would be out of specification using the existing calender rolls. The costs and timelines associated with a

change in calendar rolls are assessed in the following section. ENTEK has over 40 different calender/profile

rolls at its UK plant that would need to be re-machined or replaced if any of the alternative solvents are used.

While acetone gives nearly the same shrinkage as TRI, it is not a viable choice because of its slow extraction

rate.

49

Electrochemical Compatibility

Residual solvent in the final separator can have a potential impact on the performance and life of a Pb-acid

battery. As such, we evaluated the electrochemical compatibility (ECC) of leachates from separator samples

that were extracted and dried from the alternative solvents to a residual oil content of 14%. In this test, a 7

gram sample from each separator type was leached in sulphuric acid (sp. gr. = 1.21) for 7 days at 60 °C. A

cyclic voltammogram was performed on pure sulphuric acid (sp. gr. = 1.21) and then on the same acid with

10 ml of leachate. The 3-electrode apparatus for performing the cyclic voltammograms is shown in Figure

4.3. The cathodic and anodic scans for a TRI-extracted separator are shown in Figures 4.4 and 4.5,

respectively.

Figure 4.3.Schematic diagram of the electrochemical cell used for ECC testing.

stopcock

Hg/HgSO4

Referenceelectrode (RE)

Lead (Pb) counter

Electrode (CE)

Lead (Pb) rotating disk working electrode (WE)

50

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

-1.8 -1.6 -1.4 -1.2 -1.0 -0.8

Cu

rre

nt (m

A)

Voltage vs. Ref.

120601 TCE-extracted - Cathodic Scan

blank leachate

Figure 4.4. Cathodic scan for TRI-extracted separator shows only a small increase in

hydrogen overpotential with little change in the charge or discharge peaks.

-7.0

-6.0

-5.0

-4.0

-3.0

-2.0

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0.8 1.0 1.2 1.4 1.6 1.8

Cu

rre

nt (m

a)

Voltage vs. Reference

120606 TCE-extracted - Anodic Scan

blank

leachate

Figure 4.5. Anodic scan for TRI-extracted separator shows no change in oxygen evolution, or

in the charge and discharge peaks.

Hydrogen evolution current

Discharge peak

Charge peak

Oxygen evolution currennt

Charge peak

Discharge peak

Oxygen evolution currennt

51

ENTEK performed ECC tests on separators extracted from each of the alternative solvents. Leachates from

all of the separators had a minimal impact upon the behavior of either the negative (cathodic scan) or

positive (anodic scan) lead electrode. Leachates from separators extracted with the alternative solvents had a

larger increase in the hydrogen over-potential (> 50 mV at 1 mA) as compared to the TRI-extracted

separator. The increase in hydrogen overpotential could actually lead to some beneficial results in a lead-

acid battery (e.g., reduced water loss). As such, all of the alternative solvents appear viable based upon ECC

testing.

Separator Properties

The two most important battery separator properties are electrical (ionic) resistance and mechanical strength,

in particular puncture strength. Battery separators, extracted to 14% residual oil with the alternative

solvents, were tested in accordance with Battery Council International (BCI) test procedure #03B3 to

measure electrical resistance. In this test, the separators were first boiled in water for 10 minutes and then

soaked in sulphuric acid (sp.gr = 1.28) for 20 minutes prior to measuring their electrical (ionic) resistance in

a Palico Low Resistance Measuring System unit. The Palico measures the resistance drop between carbon

electrodes while the separator covers an open orifice that allows current to travel through it. The resistance

drop is then multiplied by the open orifice area to give units of mohm-cm2. Electrical resistivity (mohm-cm)

was obtained for each separator type by dividing the electrical resistance (mohm-cm2) by the backweb

thickness (cm).

As shown in Figures 4.6 and 4.7, the electrical resistance and electrical resistivity of the separators is

independent of the extraction solvent, even though differences in shrinkage were observed during drying

from the alternative solvents. This result would indicate that some of the porosity in separators that shrank

the least is not being filled with acid and thus not contributing to ionic conduction. As used in these figures

TCE means TRI.

52

Alternative TCE Solvents: Boiled ER

14% Residual Oil, 2.3:1

0

20

40

60

80

100

120

Tri-CE DCM Vertrel SDG n-Hexane Tetra-CE n-PB HFE 72DE D-Limonene

Ele

ctr

ical R

esis

tan

ce (

mΩ

-cm

²)

Figure 4.6. Electrical resistance (mohm-cm

2) of battery separators extracted with various

solvents to a 14% residual oil content.

Alternative TCE Solvents Study: Boiled ER


0

500

1000

1500

2000

2500

3000

3500

Tri-CE DCM Vertrel SDG n-Hexane Tetra-CE n-PB HFE 72DE D-

Limonene

Ele

ctr

ica

l R

es

isti

vit

y (

mΩ

-cm

)

Figure 4.7. Electrical resistivity (mohm-cm) of battery separators extracted with various

solvents to a 14% residual oil content.

53

The tensile strength of the separators was measured in an Instron machine in both the machine direction

(MD) and cross-machine direction (CMD) at a cross-head speed of 500 mm/min. The puncture strength of

the separators was measured in accordance with BCI test procedure # 03B11 using a 1.9 mm diameter

flathead pin. The absolute puncture strength was then divided by the backweb thickness to provide a

comparison of the separators produced from different extraction solvents.

As shown in Figures 4.7 and 4.8, there is no statistical difference in the MD and CMD tensile strength for

any of the separators. Figure 4.9 shows that puncture strength, normalized for backweb thickness, is also

nearly the same for all separator types. The slight increase in puncture strength (~ 5%) for the separator

extracted with D-limonene is considered insignificant.

Alternative TCE Solvents Study: MD Tensile


0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0


Peak

Str

ess

- M

D (

MP

a)

Figure 4.8. Machine-direction (MD) tensile strength for separators extracted and dried from

alternative solvents.

54

Alternative TCE Solvents Study: XMD Tensile


0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0


Peak

Str

ess

- X

MD

(M

Pa)

Figure 4.9. Cross machine direction (CMD) tensile strength for separators extracted and

dried from alternative solvents.

Alternative TCE Solvents Study: BW Puncture


0

5

10

15

20

25

30

35

40

45


Backw

eb

Pu

nctu

re (

N/m

m)

Figure 4.10. Normalized puncture strength (N/mm) for separators extracted and dried from

alternative solvents.

In conclusion, the electrical and mechanical properties of the separators extracted and dried from the alternative solvents are similar to the control separator produced from TRI.

Conclusions on the trials of possible solvent alternatives

The ‘bench scale’ trail on the substances that may be possible alternatives is summarised in Table 4.5.

55

Table 4.5 Summary of solvent trials on polyethylene sheet compared to TRI

Solvent Hansen

(predicted

solvation

with oil -

lower is

better)

Residual oil

extraction

time

(compare

with TRI

extracted)

Sheet properties – (compare with TRI

extracted)

Shrinkage Electrochemical

properties

Stength and

puncture

n-Hexane 0.4 faster lower similar similar

Dichloromethane

(DCM)

0.8 faster lower similar similar

Tetrachloroethylene 0.9 slower higher similar similar

Vertrel SDG N/A faster lower similar similar

HFE 72DE 0.7 faster lower similar similar

n-Propyl bromide 0.8 slower similar similar similar

D-Limonene 0.5 slower higher similar similar

Acetone 1.1 fail similar similar similar

It is stressed that the above trial will only give an indication of the potential for other solvents to perform the

oil extraction function of TRI. As indicated in Table 2.1 there are a number of other critical functions of TRI

that would also need to be fulfilled in order for TRI to be replaced. A key property is the compatibility with

the solvent capture and recycling system that allows recovery and reuse of the solvent in the ENTEK

process. It is not a surprise that n-hexane is an effective solvent for extraction of oil from PE separator sheet,

since it is known that n-hexane is used for this purpose in the production of PE separators. However, a

critical consideration for the selection of possible alternatives is the hazard/risk profile of the substance and

this is considered in depth in Section 5.

4.2.2 Manufacturing Alternatives

Confidential

65

4.2.2 Data searches

ENTEK is aware of the solvent substitution work that has been done in the pharmaceutical industry

(www.acs.org/gcipharmaroundtable) and at the Toxics Use Reduction Institute (TURI) of the University of

Massachusetts-Lowell (www.turi.org). A review of the work done at these organizations reveals that there

are no clear alternatives to TRI for battery separator applications.

4.2.3 Consultations

ENTEK is working directly with Dow Chemical and Safechem regarding the continued use of TRI in battery

separator production. In addition, ENTEK has hired Peter Fisk Associates to serve as Project Manager to

coordinate the multiple aspects of our authorization application. ENTEK has also consulted with Professor

James Hutchinson, who heads up the Green Chemistry program at the University of Oregon, which is located

near the ENTEK-US manufacturing plant.

http://www.acs.org/gcipharmaroundtable

http://www.turi.org/

66

ENTEK is also working with several battery separator customers to better understand the costs and timeline

for original equipment manufacture’s (OEM) approval of batteries that would be built with separators from a

new or modified separator manufacturing process. Details of these consultations are in the SEA report.

67

5. SUITABILITY AND AVAILABILITY OF POSSIBLE ALTERNATIVES

5.1 INTRODUCTION

As detailed in Section 3.2 a research programme was initiated to identify possible viable substance

alternatives.

Confidential

In all cases however, none of these possible alternatives is either suitable or presently available to ENTEK

and thus the application for authorisation is made on the basis that no alternative can be used to replace TRI

in the ENTEK process for some years.

5.2 N- HEXANE

5.2.1 Substance ID and properties

Chemical Name(s): hexane

Other names: Methyl pentane, n-Hexane, Hexyl hydride

Trade Name(s): Skellysolve B; n-C6H14; Esani; Heksan; Hexanen; Hexyl hydride; Gettysolve-B; NCI-

C60571; NSC 68472

CAS Number: 110-54-3

EC Number: 203-777-6

Molecular Formula: C6H14

Molecular weight: 86.18

Classification and Labelling

The harmonised classifications according to the CLP regulation no. 1272/2008 and according to the

Dangerous Substances Directive 67/548/EEC are presented in the tables below.

68

Classification

area

CLP - according to Regulation No

1272/2008 Annex VI

Dangerous Substance Directive –

according to Directive 67/548/EEC

Physicochemical Flam. Liq. 2 F; R11

Health Asp. Tox. 1 Repr. Cat. 3; R62

Skin Irrit. 2 Xn; R65-48/20

STOT SE 3 Xi; R38

Repr. 2 R67

STOT RE 2

Environmental Aquatic Chronic 2 N; R51-53

Hazard

Statements

H225: Highly flammable liquid and vapour 11: Highly flammable

H304: May be fatal if swallowed and enters

airways

65-48/20: Harmful: danger of serious

damage to health, may cause lung damage

if swallowed

H315: Causes skin irritation 38: Irritating to skin

H336: May cause drowsiness or dizziness 67: Vapours may cause drowsiness and

dizziness

H361f: Suspected of damaging fertility 62: Possible risk of impaired fertility

H373: May cause damage to organs

through prolonged or repeated exposure

H411: Toxic to aquatic life with long

lasting effects

51-53: Toxic to aquatic organisms, may

cause long-term adverse effects in the

aquatic environment

Hexane is a highly volatile hydrocarbon that is a major component of gasoline. A summary of the physico-

chemical properties are presented in Table 5.1. The human health and environmental classifications for

hexane are listed above.

Table 5.1 Physico-Chemical Properties of hexane

Properties Characteristics of Chemical

Source(s) of Information

Flammability Highly flammable HSDB, 2013

Vapour pressure 20 kPa at 25°C HSDB, 2013

Boiling point 68.73°C HSDB, 2013

69

Properties Characteristics of Chemical


Melting point -95.35°C HSDB, 2013

Water solubility 9.5 mg/L at 25 °C HSDB, 2013

Log Kow 3.90 HSDB, 2013

5.2.2 Technical feasibility

As discussed in Section 4.2.1, n-hexane is an effective solvent for naphthenic process oils and the laboratory

scale experiments showed that separators treated with hexane have properties that are similar to the TRI-

extracted separators. ENTEK knows that one of its separator competitors uses hexane as an extraction

solvent at its plant in France (and also at their US plant in Owensboro, Kentucky), but it must be recognized

that this competitor does not use a continuous process for the manufacture of battery separators. In the n-

hexane process, oil-filled sheet is manufactured in very large rolls that are subsequently unwound and passed

through a shallow pan extractor filled with hexane. The extraction equipment is located outside the main

building, and the operators monitor the operation behind an explosion-proof wall.

It is believed that this multistep, staged process (in contrast to the ENTEK continuous separator

manufacturing process) is used by a competitor to partially isolate the explosion and fire risk associated with

the extraction and drying of the oil filled sheet. In their case, the extrusion and calendering part of the

process and the final slitting process for converting jumbo rolls into finished slit rolls with the appropriate

width for enveloping are isolated from the highest risk step of extraction and drying with n-hexane. In a

continuous separator manufacturing process, the risk cannot be decoupled from the extrusion, calendering

and slitting operations in order to result in a product that is usable by the battery manufacturer in its

enveloping process.

Further consideration of the feasibility of replacement of TRI with n-hexane is considered in detail below.

Substituting n-hexane for TRI at ENTEK International LTD

The three major concerns for substituting hexane for TRI in the ENTEK battery separator plant in Newcastle,

UK are:

1. Flammability of n-hexane and lack of possibilities in the current ENTEK plant design for handling

an R11 substance in the process.

2. Capital equipment and operational modifications unrelated to flammability – for example in the

processes for oil extraction and solvent recovery - required to allow substitution.

3. Customer acceptance of the substitution.

70

The high flammability of n-hexane is the foremost concern. Comparing n-hexane to TRI:

Hexane Trichloroethylene

Flash Point -22°C -

Auto-Ignition Temperature 225°C 414°C

Lower Flammability Limit 1.1 vol. % 12.0 vol. %

Upper Flammability Limit 7.5 vol. % 40.0 vol. %

Boiling Point 68.5°C 87.6°C

Vapour Pressure in mm Hg @ 20°C 121 60

R Phrases for Flammability R11 -

Trichloroethylene’s auto-ignition temperature is quite high and its flammability limits are above the range

that would be measured around process equipment under any foreseeable process scenario.

Trichloroethylene is classed by most sources as non-flammable, for example by the European Chlorinated

Solvent Association. These factors make the use of TRI a negligible risk for fire or explosion in the battery

separator process.

In contrast to TRI, hexane has the R11 risk phrase ‘highly flammable’, a significantly lower auto-ignition

temperature and flammability limits that could be reached during normal process operations. Hexane is

approximately twice as volatile as TRI at room temperature: the combination of high volatility and low

flammability limits makes the possibility of fire quite high in a process not specifically designed for the use

of hexane.

Mitigating the risk of fire and explosion in the use of hexane for making battery separators will require

extensive engineering design, equipment and facilities modifications, and changes to operational practices.

71

Engineering Design Changes for Hexane Use

Processing highly flammable liquids in an industrial process requires careful attention to sources of ignition.

Electric motors, electrically powered instruments, lighting, electrical panels, junction boxes, rotating

equipment and any item capable of carrying a static charge are all areas of concern. Battery separator sheet

in both the oil-filled (~65% oil by weight) and finished state (~15% oil by weight) can carry a high static

charge. In a battery separator process using hexane all of these ignition sources pose a serious hazard to

human health and capital investment. Mitigating the risks posed by these ignition sources would be both

prudent and legally mandated.

The analysis of risk begins by defining the areas within the production process that are at risk of fire and

explosion due to the presence of the flammable compound. There are three zones to be considered:

1. Zone 0: Explosive gas-air mixture is continuously present or present for long periods

2. Zone 1: Area in which an explosive gas-air mixture is likely to occur for short periods in normal

operation

3. Zone 2: Area in which an explosive gas-air mixture is not likely to occur and, if it does occur,

will only exist for a short time due to abnormal process conditions.

An ATEX2 notified body must certify equipment rated for and used within zones 0 and 1. Manufacturers

can self-certify equipment for use in zone 2.

Broadly speaking, the following engineering analysis and changes in ENTEK capital equipment would be

required:

2 Directive 94/9/EC of the European Parliament and the Council of 23 March 1994 on the approximation of the laws of

the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres.

If a conformity assessment procedure under the Directive calls for third-party intervention, this is then undertaken by

so-called "Notified Bodies", who are appointed by the Member States because they have the relevant expertise and

facilities to undertake the required procedures.

This might include a "Type Examination", which involves an assessment made of the product against the EHSRs of the

Directive, or even (amongst others) a report of the manufacturer's quality assurance procedures to ensure that the "type"

will continue to comply with the requirements.

Whilst these Bodies are given a number and are listed in the NANDO Information System prior to their operation, the

activities of Notified Bodies are a matter for Member States, as they are appointed under their authority.

In addition, whilst the Notified Body has various responsibilities under the Directive, the manufacturer (or authorised

representative) always remains responsible for the compliance of the equipment.

72

1. Analyse for and define the zone classification for hexane-air mixtures in the battery separator

process.

2. In any locations defined as zone 0 or 1, replace all equipment not specifically certified for use in

zones 0 or 1 with properly rated equipment.

a. At minimum, the following items would need to be replaced: electric motors, electrically

powered instruments, electrical devices, electrical enclosures and most/all electrical wiring.

b. ENTEK’s affiliate ENTEK Manufacturing LLC, designs and builds capital equipment for

making battery separator. Some or all of this equipment would be within zone 0 or zone 1

classified locations. Whether this equipment could be certified ex post is unknown at this

time; it is possible that some or all of the existing process equipment would have to be re-

engineered, built, certified and installed according to ATEX requirements to satisfy the

regulator’s requirements.

3. In locations defined as zone 2, equipment can be self-certified by the manufacturer. This fact would

not relieve ENTEK of the legal and moral obligation to provide a safe workplace.

Hexane Process Areas Likely To Be Classified Zone 0, 1 or 2

A provisional analysis of ATEX classifications for the processes where hexane would be present in making

battery separators was undertaken to judge the scope and cost of the conversion from TRI to hexane. The

results of that analysis are shown in the table on the next page.

Flammable mixtures of hexane and air would or could be present within and/or around all battery separator

processes starting with the oil extraction step through the sheet finishing operation at the winder.

Further, the distillation equipment that would be used to separate hexane from oil could be expected to have

flammable hexane and air mixtures around the equipment under upset conditions.

The carbon beds used to recover the oil-extracting solvent could have explosive mixtures within the carbon

beds under normal operating conditions; explosive mixtures could be present outside the carbon beds and

their associated condensers, decanters, and storage tanks under upset conditions.

All hexane storage tanks could contain explosive mixtures of hexane and air; under upset conditions there

could be explosive mixtures outside the tanks.

ENTEK’s provisional analysis of likely ATEX zone classifications for a battery separator process using

hexane indicates extensive areas of zone 0, 1 and 2 classification. All equipment in zones 0 and 1 would

need to be ATEX certified. This zone would likely include the extractors, dryers, ovens, sheet finishing,

carbon beds and hexane storage tanks. Most of this equipment is currently built internally by ENTEK

utilizing our proprietary knowledge of battery separator manufacturing to afford the company a competitive

73

advantage in the battery separator market. The equipment in these areas currently installed in ENTEK’s

Newcastle facility was not designed for use with a flammable solvent like hexane. It is likely that this

equipment would need to be re-designed, built, and installed to obtain the legally mandated ATEX

certification for using hexane.

75

Physical Isolation of Processes Using Hexane

One of the most effective safety measures for processes classified as zone 0 or zone 1 is physical isolation.

Isolation entails housing the process in an unmanned room separated from the zone 3 and unclassified

process areas by walls. High ventilation rates within the enclosed space insure that flammable gases do not

build up to dangerous levels. The isolated room is equipped with fire suppression equipment and explosion-

relief venting. Isolating the zone 0 or zone 1 processes serves as a reminder to personnel who occasionally

work in these areas that special precautions are required to work in the classified area.

Unfortunately, the ENTEK process was designed in 1988 to be a continuous process using a non-flammable

liquid solvent for oil extraction. There was no provision in the design for isolating any part of the process

and no extra room was planned into the production facility to house such a process. These facts mean that

physical isolation would be very difficult to implement at ENTEK’s facility.

5.2.3 Reduction of overall risk due to transition to the alternative

Hexane is subject to a SCOEL recommendation for an occupational exposure limit for the protection of

workers at EU level8. The iOEL is summarised as follows:

8 hour TWA: 20 ppm [72 mg/m3]

STEL (15 min): No STEL or "skin" notation was considered to be necessary-

Table 5.2 below summarises further information on the hazard profile of the substance.

8 Recommendation from the Scientific Committee on Occupational Exposure Limits on Tetrachloroethylene

(perchloroethylene) SCOEL/SUM/133, June 2009

76

Table 5.2 hazard profile of n-hexane

Human Health Hazards

Acute Toxicity

Acute toxicity Hexane has low acute toxicity with inhalation LC50 value of >5000 ppm. SUM 1995

Acute inhalation exposure of humans to high levels of hexane causes mild CNS depression.

CNS effects include dizziness, giddiness, slight nausea, and headache in humans.

Acute exposure to hexane vapours may cause dermatitis and irritation of the eyes and throat in

humans.

US EPA 2000

Skin or eye

corrosion/irritation

Hexane is classified as a skin irritant, however it is not classified as an eye irritant.

Inhalation can cause respiratory irritation.

ECHA 2013

Respiratory or skin

sensitisation

n-hexane is not considered to be a sensitizing agent. ECHA 2013

Chronic toxicity

Carcinogenicity EPA has classified hexane as a Group D, not classifiable as to human carcinogenicity, based on

a lack of data concerning carcinogenicity in humans and animals.

It is not classified by IARC.

US EPA 2000

Long term toxicity The main effect of repeated exposure to hexane in laboratory animals and in humans is

characterized by neurotoxicity. The clinical signs of neurotoxicity from hexane include limb

weakness progressing to paralysis.

SCOEL 1995

In humans repeated exposure to inhaled hexane resulted in sensorimotor polyneuropathy, with

numbness in the extremities, muscular weakness, blurred vision, headache, and fatigue

observed.

US EPA 2000

Reproductive and

developmental

toxicity

Testicular damage has been observed in male rats exposed to hexane via inhalation.

Rats exposed chronically exposed to hexane via inhalation showed CNS effects and decreased

body weight at concentrations at which maternal toxicity was also observed (1500 ppm or 5370

mg/m3).

SCOEL 1995

77

Mutagenicity Hexane is considered a weak mutagen in the absence of metabolic activation. ECHA 2013

Endocrine disruption No information

Neurotoxicity Neurotoxic effects to both the peripheral and the central nervous systems of humans may occur

after exposure to n-hexane.

HSDB, 2013

Immune system

toxicity

No information

Systemic toxicity yes, effects to the peripheral and central nervous system.

Cardiotoxicity Sub-cutaneous exposure of rats to 0.1 ml n-hexane for 30 days resulted in cardiotoxicity.

90 days subcutaneous exposure to 0.1 ml of hexane resulted in lowered ventricular fibrillation

threshold and lowered levels of magnesium, potassium, and zinc in rats.

ECHA 2013

Toxic metabolites The main metabolite of hexane is 2-5,hexanedione, a neurotoxic agent. SCOEL 1995

Environmental effects/toxicity

Degradation 100% degradation has been achieved after 4 weeks in a Japanese MITI test.

HSDB, 2013

Bioaccumulation The calculated BCF is 501.87. It does not meet the criteria for B in PBT.

However the log Kow is greater than 3, therefore the substance has potential for

bioaccumulation.

ECHA 2013

Acute/chronic

aquatic toxicity

There are no aquatic toxicity data with n-hexane in the disseminated dossier, however the

substance is classified as Aquatic Chronic 2 under CLP.

ECHA 2013

Fish toxicity LC50 values have been reported as low as 2.5 mg/l with Pimephales promelas. An

invertebrate EC50 value of 45 mmol/m3 has been reported with Daphnia magna and an algal

EC50 value of 94 mmol/m3has been derived with Chlamydomonas angulosa (green algae).

HSDB 2013

Greenhouse gas

formation potential

Hexane is not identified as a greenhouse gas.

Ozone-depletion

potential

Hexane is not classed as an ozone depleting substance.

Regulation (EC) No 2037/2000

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n-Hexane is metabolised to 2-5,hexanedione, a neurotoxic agent. Acute exposure to hexane can cause

respiratory and skin irritation, and effects to the central and peripheral nervous systems (such as dizziness),

which may result in damage to peripheral nerves. The substance is in fact classified for acute effects under

CLP as an Aspiration Toxicant 1, Skin Irritant 2 and STOT SE 3, with the associated hazard statements,

amongst others, H335 and H336 (may cause respiratory irritation and may cause drowsiness or dizziness).

The main effect of repeated exposure to hexane is neurotoxicity, which may progress to paralysis. It may

also cause testicular damage and maternal toxicity. It is classified under CLP as a Reproductive toxicant 2

and STOT RE 3. It is therefore not considered to be a safe substance from a human health point of view.

In addition, hexane has the potential to bioaccumulate in the environment (log Kow >3), even though it does

not meet the criteria for B in PBT due to its bioaccumulation factor being below the threshold value for B

(501.9 against the cut-off value of 2000 L/kg) and it is toxic to fish in short-term toxicity studies with the

lowest LC50 value of 2.4 mg/L (no long-term aquatic toxicity data are available). Hexane is classified under

CLP as Aquatic Chronic 2.

PBT and CMR

As a reproductive toxicant category 2, hexane would be considered to meet the toxicity (T) criterion for PBT,

but not the reproductive toxicity (R) criterion for CMR, thus it is not has been proposed as a substance of

very high concern (SVHC).

Hexane is being assessed in the REACH CoRAP program due to concerns for human health/CMR and

neurotoxicity; exposure/wide dispersive use and high aggregated tonnage.

5.2.4 Economic feasibility

Cost Estimate to Change ENTEK’s UK Facility to n-hexane

n-Hexane is not a “drop-in” solvent replacement for TRI as noted above. It would mean the replacing large

parts (if not completely) the existing production process and equipment. As per the ECHA SEA guidance,

the lost (book) value of existing equipment is considered a ‘sunk cost’ and therefore not considered in the

analysis. The additional capital and operating costs of making PE SLI battery separators is however relevant

to the assessment of economic feasibility.

Changing the ENTEK facility over to use hexane as an oil-extracting fluid in place of TRI would require a

long-term engineering effort, engagement of ATEX authorities, permitting, and capital equipment design,

build, install and start-up efforts. At this time, it is not known whether the existing facility could be re-

engineered and re-built to safely use hexane. These facts make any cost estimate for the change from TRI to

n- hexane subject to large uncertainty. In order to model this uncertainty:

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Scenario 1 considers the economic feasibility of retrofitting the existing equipment to be able to use

hexane; and

Scenario 2 considers the economic feasibility of new equipment to use hexane.

Scenario 1

Scenario 1 is the least expensive conversion scenario in terms of time and capital investment as it assumes it

is possible to convert the existing equipment and certify it per ATEX requirements to use hexane. An

extensive engineering study and consultation with an ATEX notified body would be needed to determine if

this option is feasible. Assuming this approach is found to be feasible, a first-pass estimate of the timeline

and cost is estimated below at €9.98 million over 45 months (3.75 years). This time excludes qualification

time required by battery manufacturers (minimum 2 years of 24 months – See SEA section 3.2).

Hexane Conversion Time and Cost: Modify Equipment

Preliminary Engineering Analysis Months Cost (ϵ)

Engage ATEX consulting resource 1 € 37,619

Classify Existing Processes into ATEX Zones 4 € 149,048

Identify Opportunities to Re-Classify 3 € 106,429

Determine Feasibility of Conversion 3 € 106,429

Draft Conversion Plan 1 € 35,476

Total for ATEX-Related Activities 12 € 435,000

Prototyping and Design Data Acquisition

Extraction, Drying, Oven, Distillation, Carbon Recovery 12 € 869,643

Design/Build

Design Equipment 9 € 790,089

Build Equipment 9 € 2,928,214

Install Equipment 3 € 4,925,536

Total For Design/Build Activities 21 € 8,643,839

Grand Total 45 € 9,948,482

80

Table 5.3 shows that the minimum cost to ENTEK is ~ €55million net present value (NPV). It is considered

a minimum costs as it excludes some additional costs like redundancy (over the period 2016-2019) and

assumes post 2019, ENTEK can make equivalent profits. This assumption is however highly unlikely since

the new battery separator would (i) still need to be qualified by customers (up to 2 years) given the

significant changes in the production process, (ii) assumes ENTEK would not have lost any market share due

to no sales after the sunset date (April 2016) to 2019, and (iii) assumes profit margins would be similar

compared to using TRI (which is highly unlikely given no new plants across the world has chosen hexane

over TRI).

Table 5.3 Minimum economic costs to ENTEK of switching to hexane (scenario 1)

COSTS TO ENTEK (€ million) 2016 2017 2018 2019 Total NPV

Capex costs € 0.44 € 0.87 € 1.77 € 6.88 € 9.95 € 7.85

Best estimates of lost profit (until new

production using n-Hexane is online) € 10.14 € 15.21 € 15.21 € 15.21 € 55.78 € 46.79

Total cost € 10.58 € 16.08 € 16.98 € 22.09 € 65.73 € 54.64 Notes:

1. Based on a discount rate of 7% and a base period of 2016

2. Lost profit figures have been taken from the SEA (See SEA Section 4.2.1) – lost profit is lower in 2016 as it

assumes continued production (and therefore profits from sales) with TCE up until the sunset date.

When comparing the minimum cost of switching to hexane is at least €54.6m with the cost of building

additional production lines at the existing US site (in Oregon) which is €48m (see Section 4.2.2 of the SEA);

which enables ENTEK to avoid any production/sales disruption (i.e. can provide battery separators to the

existing markets after the sunset date), it is clear that switching to hexane is not economically feasible.

Factoring in the additional time (2 years) for product qualification, this increases lost profit beyond 2019 (i.e.

up to 2021), resulting in a total cost to ENTEK of €76 million (NPV). If it is also assumed that it takes a

further 5 years for ENTEK to recover their market share (i.e. 80% of lost profit in 2022, declining linearly to

0% in 2026) then the net cost to ENTEK is €93 milion (NPV). This further reinforce the conclusion that

hexane is not economically feasible.

Scenario 2

The Scenario 1 estimate (€93 million) assumes that the existing equipment can be modified to use hexane in

place of TRI despite the substantial differences in physical properties and processing characteristics of the

two substances. This assumption is unlikely to be satisfied for at least some of the existing equipment and

quite possibly all of it, which is modelled below as Scenario 2. It will only be clear at the end of the

“Prototyping and Design Data Acquisition” phase of the project if all new equipment is required.

81

The most time-consuming and costly option for conversion to hexane is the need to replace all existing

equipment in ATEX zones 0 and 1. A first-pass estimate of the time and cost to accomplish the conversion

is estimated below at €43.86million over 84 months (7 years). This time excludes qualification time required

by battery manufacturers (minimum 2 years of 24 months – See SEA section 3.2).:

Hexane Conversion Time and Cost: New Equipment

Preliminary Engineering Analysis Months Cost (ϵ)

Engage ATEX consulting resource 1 € 37,619

Classify Existing Processes into ATEX Zones 4 € 149,048

Identify Opportunities to Re-Classify 3 € 106,429

Determine Feasibility of Conversion 3 € 106,429

Draft Conversion Plan 1 € 35,476

Total for ATEX-Related Activities 12 € 435,000

Prototyping and Design Data Acquisition

Extraction, Drying, Oven, Distillation, Carbon Recovery 12 € 869,643

Design/Build

Design Equipment 24 € 3,054,286

Build Equipment 24 € 29,945,714

Install Equipment 12 € 9,552,143

Total For Design/Build Activities 60 € 42,552,143

Grand Total 84 € 43,856,786

Table 5.4 shows that the minimum cost to ENTEK under scenario 2 is ~ €107 million (NPV). Similarly to

scenario 1, it is considered a minimum costs as it excludes some additional costs like redundancy (over the

period 2016-2022) and assumes post 2022, ENTEK can make equivalent profits. This assumption is

however highly unlikely since the new battery separator would (i) still need to be qualified by customers (up

to 2 years) given the significant changes in the production process, (ii) assumes ENTEK would not have lost

any market share due to no sales after the sunset date (April 2016) to 2022, and (iii) assumes profit margins

would be similar compared to using TRI (which is highly unlikely given no new plants across the world has

chosen hexane over TRI).

Table 5.4 Minimum economic costs to ENTEK of switching to hexane (scenario 2)

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COSTS TO ENTEK (€ million) Total costs 2016-2022 NPV

Capex costs € 44 € 30

Best estimates of lost profit (until new production using n-

Hexane is online) € 101 € 77

Total cost € 145 € 107 Notes:

1. Based on a discount rate of 7% and a base period of 2016

2. Lost profit figures have been taken from the SEA (See SEA Section 4.2.1) – lost profit is lower in 2016 as it

assumes continued production (and therefore profits from sales) with TCE up until the sunset date.

When comparing the minimum cost of switching to hexane is at least €107m with the cost of

building additional production lines at the existing US site (in Oregon) which is €48m (see Section

4.2.2 of the SEA); which enables ENTEK to avoid any production/sales disruption (i.e. can provide battery

separators to the existing markets after the sunset date), it is clear that switching to hexane is not

economically feasible under scenario 1 or 2.

Factoring in the additional time (2 years) for product qualification, this increases lost profit beyond

2022 (i.e. up to 2024), resulting in a total cost to ENTEK of €114 million (NPV). If it is also

assumed that it takes a further 5 years for ENTEK to recover their market share (i.e. 80% of lost

profit in 2024, declining linearly to 0% in 2028) then the net cost to ENTEK is €139 million (NPV).

This further reinforces the conclusion that hexane is not economically feasible under scenario 1 or 2.

Practicality of Hexane Conversion at the Newcastle Facility

Given that more than half of the major equipment in the Newcastle facility would at minimum need to be re-

designed - and more likely be replaced - to convert the facility to hexane and comply with ATEX

requirements, the feasibility of conversion is called into question. The existing plant does not have the

required space to duplicate all of the equipment installations to allow uninterrupted operation of the facility

during the conversion process.

For example, the plant must have a carbon bed system in-place and operational on an uninterrupted 24/7

basis to comply with legally mandated air discharge requirements imposed by the UK Environmental

Authority. The existing carbon beds were not designed for use with a flammable solvent and this equipment

will likely have an ATEX zone 0 classification inside and around the carbon beds if the Newcastle facility

converts to hexane. Assuming it is possible to modify the existing beds to meet ATEX zone 0 requirements,

all required modifications would need to be accomplished in 2 weeks or less to avoid interrupting battery

separator supply to ENTEK’s customers.

83

If a re-build and re-installation of new beds is required, the old carbon beds would need to be removed and

the new carbon beds installed to effect the conversion to hexane. This too would need to be accomplished in

2 weeks or less to avoid interrupting battery separator supply.

Now, consider the entire conversion process from TRI to hexane. The ENTEK Newcastle facility does not

have the infrastructure to run TRI and hexane processes in parallel, nor does it have enough space to install a

second process using hexane in parallel with the existing TRI process. Extensive removal of the equipment

designed for TRI, installation of the new hexane-using equipment, and re-wiring to ATEX zone 0 through 2

standards would have to be performed to bring the facility into compliance for hexane use. The plant outage

to accomplish this much work would take up to 12 months, an undertaking that would remove a substantial

amount of battery separator supply from the EU market. ENTEK would break contractual supply

commitments to customers and likely deal its business a commercial blow from which it would never

recover.

5.2.5 Availability

The substance has been registered under REACH at a 10,000 to 100,000 tonnes per annum band, therefore it

can be considered to be readily available.

5.2.6 Conclusion on suitability and availability for n-hexane

n-Hexane is not a technically feasible alternative because the extraction and drying steps are an integral part

of the continuous process that ENTEK uses to manufacture battery separators. The potential consequence of

a fire or explosion with over ~34,000 litres of hexane being circulated in a closed loop process at the UK

plant would be catastrophic. The extraction and drying steps could not be isolated without a complete

retrofit of the ENTEK manufacturing process and the plant infrastructure. The large cost to switch to hexane

compared to the costs of building additional production lines in the US, means this alternative is also not

economically feasible. Even if such a project were completed at great capital expense, the human health

risks associated with hexane are substantial and would not justify a change from the current extraction

solvent.

As mentioned in Section 4, n-hexane is known to be used for the production of PE separators, but there are

key technological reasons why ENTEK (and others) has opted for a continuous closed loop process using

TRI. Interestingly, the competitor that uses n-hexane in France and one of its US operations, has elected to

use TRI at its other three manufacturing locations (Thailand, China, USA) which have been more recently

acquired or built. This fact indicates that this competitor views TRI as a better choice for the production of

separators as compared to n-hexane.

84

As well as the technological disadvantages of the use of n-hexane there are clear risk indicators for not

switching to n-hexane, due to its flammability and its toxicity. As indicated in this section below, n-hexane

is currently classified as a reproductive toxin (albeit as a suspected reproductive toxin - Cat 3.) and it is also

indicated to have specific target organ toxicity affecting the nervous system (STOT RE 2, H373). Although

the substance is not currently an SVHC it is on the CoRAP list.

Given the volatility of n-hexane and its low DNEL (long term DNEL for neurotoxicity for workers is 75

mg/m3 (~21 ppm)) (the SCOEL iOEL (1995) is 72 mg/m

3 (20 ppm)) 8 hour TWA), the problems associated

with control of this substance are similar to TRI and the impacts to health, whilst not cancer, can cause long-

term illness. The conclusion from a hazard and risk management point of view is that there is no advantage

in use of n-hexane over TRI, the only advantage is that n-hexane is not designated as a SVHC today,

although the indications are that it could well be subject to further restrictions on use in the future.

The toxicological profile and the continued regulatory pressure on dangerous substances like n-hexane, mean

that the considerable investment to switch from TRI to n-hexane cannot be easily justified.

85

5.3 DICHLOROMETHANE


Chemical Name(s): dichloromethane

Other names: Methylene chloride, methylene dichloride

Trade Name(s): Solmethine, Narkotil, Solaesthin, Di-clo, Freon 30, R-30, DCM, UN 1593, MDC

CAS Number: 75-09-2


Molecular Formula: CH2Cl2

Molecular Weight: 84.93


The classifications according to the CLP regulation no. 1272/2008 and according to the Dangerous

Substances Directive 67/548/EEC are presented in the tables below. Both the harmonised classification and

the self-classification provided by the REACH disseminated dossier registrants are presented.CLP -

according to Regulation No 1272/2008 Annex VI

Classification

area

Harmonised Self-classification

Phsyicochemical Not classified Not classified

Health Carc. 2 Carc. 2

Skin Irrit. 2

Eye Irrit. 2

STOT SE 3.


Route of exposure: inhalation

Environmental Not classified Not classified

Hazard H351: Suspected of causing cancer H351: Suspected of causing cancer

86

Classification

area


Statements

H315: Causes skin irritation

H319: Causes serious eye irritation

H336: May cause drowsiness or dizziness

Dangerous Substance Directive – according to Directive 67/548/EEC

Classification

area


Health hazards Carc. Cat. 3; R40 Carc. Cat. 3; R40

Xi; R36/38

Risk Phrases R40: Limited evidence of a

carcinogenic effect

R40: Limited evidence of a carcinogenic effect

R36/38: Irritating to eyes and skin

R67: vapours may cause drowsiness and

dizziness

Dichloromethane is a clear, colourless, highly volatile, non-flammable liquid with penetrating ether like

odour. The odour threshold is ≥540 mg/m3. It has a boiling point of 40°C and a melting point of -95.1°C. It

has a solubility in water of 13 g/L at 20°C and a vapour pressure of 47.4 kPa at 20°C. Pure methylene

chloride vapour is denser than air.

Pure, dry dichloromethane is relatively stable but in the presence of water and light it slowly decomposes to

produce small quantities of hydrogen chloride.

Commercial grades of dichloromethane normally contain between 0.005 and 0.02% of a stabiliser (such as

methanol, ethanol, amylene, cyclohexane, phenolic compounds or tertiary butyl amine) to prevent

acidification and corrosion1.

1 Recommendation from the Scientific Committee on Occupational Exposure Limits for methylene chloride

(dichloromethane) SCOEL/SUM/130 June 2009

87

Table 5.5 Physico-Chemical Properties of dichloromethane

Properties

Characteristics of Chemical


Flammability non-flammable SCOEL, 2009

Vapour pressure 47.4 kPa at 20°C SCOEL, 2009

Boiling point 40°C SCOEL, 2009

Melting point -95.1°C SCOEL, 2009

Water solubility 13 g/L at 20°C SCOEL, 2009

Log Kow 1.25 HSDB, 2010


From the research as described in Section 3.2 of this document it appears that dichloromethane may have the

potential to be a technically feasible alternative to TRI as a process solvent for the manufacture of

polyethylene battery separators. However, as indicated in that examination there is a considerable amount of

further research that is required in order to understand if dichloromethane could be used at a commercial

scale and would be compatible with full scale processing plant as well as meeting customer product quality

criteria. The possible steps that may be needed to determine if an alternative solvent is technically feasible

are described in Section 6.2


Whilst dichloromethane does not meet the criteria for a substance of very high concern (SVHC), it is subject

to a restriction under REACH and listed on Annex XVII of the regulation accordingly2. The restriction

limits the use of the substance in products used as paint strippers in order to control the risk to workers health

from the substance. The substance is classified as a category 3 carcinogen (under the Dangerous Substance

Directive) and subject to a SCOEL recommendation for an indicative occupational exposure limit (iOEL) for

the protection of workers at EU level3. The iOEL is summarised as follows:

8 hour TWA (time weighted average): 100 ppm [353 mg/m3]

2 COMMISSION REGULATION (EU) No 276/2010 of 31 March 2010 amending Regulation (EC) No 1907/2006 of

the European Parliament and of the Council on the Registration, Evaluation, Authorisation and Restriction of Chemicals

(REACH) as regards Annex XVII (dichloromethane, lamp oils and grill lighter fluids and organostannic compounds)


(dichloromethane) SCOEL/SUM/130, June 2009

88

STEL 15 min (short term exposure limit): 200 ppm [706 mg/m3]

BLVs (biological limit value): 4 % COHb4

0.3 mg dichloromethane / l urine

1 mg dichloromethane / l blood

Notation: ‘Skin’

SCOEL carcinogen group: C (genotoxic carcinogen for which a practical threshold is supported and a health

–based OEL is proposed).

The UK Work Exposure Limit (WEL) has set the same TWA, but a higher STEL 300 ppm (1060 mg/m3).

Based on the production of carbon monoxide as a metabolite in the blood, the IPCS (1996) has set an

exposure limit of 177 mg/m3.


4 A relevant toxic metabolite of methylene chloride is carbon monoxide. For carbon monoxide SCOEL has

recommended an OEL of 20 ppm, compatible with a biological limit (BLV) of 4% COHb (SCOEL/SUM/57D). [COHb

= Carboxyhaemoglobin]

89

Table 5.6 hazard profile of dichloromethane

Chemical Properties




Acute toxicity Low oral and dermal toxicity (>2000 mg/kg) and low inhalation toxicity (calculated 4

h LC50 86 mg/L).

ECHA, 2013

The acute toxicity of methylene chloride is low. The predominant effects in humans

are Central Nervous System (CNS) depression and elevated blood

carboxyhaemoglobin (CO-Hb) levels. These acute effects are reversible. Other target

organs include the liver and, occasionally, the kidney.

IPCS, 1996

Skin or eye corrosion/irritation Dermal contact causes a burning sensation, numbness, coldness and pain.

Eye contact with vapour can cause irritation. Contact with liquid methylene chloride

may cause corneal burns.

Heath Protection Agency IM sheet,

2011

Methylene chloride has been self-classified as a skin and eye irritant. ECHA, 2013

Respiratory or skin

sensitization

Not sensitizing

SIAP, 2011 and ECHA, 2013

Chronic toxicity

Carcinogenicity Carcinogenicity studies in rodents have shown an increase in liver and lung cancer

(when exposed to7100 and 14 100 mg/m3) and benign mammary gland tumors

following inhalation exposure to methylene chloride.

The relevance of the animal findings in humans is uncertain. From epidemiological

studies methylene chloride is not expected to be a human carcinogen.

ATSDR, 1998 IPCS, 1996 and HSDB,

2010

ECHA, 2013

Long term toxicity The predominant effects following repeated or long-term exposure to methylene

chloride are the same as for acute exposure. Mostly reversible symptoms of CNS

depression are seen in several species, including humans. Liver effects have also been

reported in animals following exposures as low as 25 ppm [88 mgm-3

] (continuous

exposure). The chronic NOAEL from an inhalation rat bioassay was 200 ppm (695

IPCS, 1996

ECHA, 2013

90

Chemical Properties



mg/m3) based on histopathological lesions in the liver and mammary tissue.

Mutagenicity Overall, the substance is not considered to be mutagenic in vivo. SIAP 2011

Methylene chloride was positive in two strains of bacteria with and without metabolic

activation, and was found to cause chromosomal aberrations in mammalian cells in

vitro at concentrations causing cytotoxicity. The substance has not been classified as a

mutagen.

ECHA, 2013

Neurotoxicity Effects on the CNS have been observed in both animals and humans. IPCS, 1996

Immune system toxicity Guideline inhalation study on rats indicated NOAEL >5187 ppm for immunotoxicity

parameters.

ECHA, 2013

Systemic toxicity The lowest NOAEL for neurotoxic effects in rats from chronic inhalation is 200 ppm. ACGIH, 2001

Toxic metabolites Biological activation of methylene chloride to toxic metabolites. The major oxidative

(saturable) pathway leads to carbon monoxide. A minor reductive (glutathione-

dependent) pathway leads to potentially reactive metabolites, such as formaldehyde.

SCOEL, 2009

Reproductive/developmental No studies were located regarding developmental or reproductive effects in humans

from inhalation or oral exposure.

Animal studies have demonstrated that methylene chloride does not affect

reproduction (fertility) parameters; it crosses the placental barrier, and minor skeletal

variations and lowered fetal body weights have been noted in the presence of

maternal toxicity.

ATSDR, 1998

ECHA, 2013

HSDB, 1993

Environmental Hazards

General Dichloromethane is naturally formed at levels exceeding industrial production Baker, et al., 2001.

Acute/chronic aquatic toxicity Dichloromethane is acutely toxic to aquatic invertebrates in the range 10 and 100

mg/L.

SIAP 2011

Bioaccumulation Methylene chloride is not expected to bioaccumulate SIAP 2011

Persistence Dichloromethane is not readily biodegradable. However, biological degradation

processes have been identified capable of mineralizing methylene chloride in a few

days. Main route of elimination is hydrolysis in the atmosphere.

IPCS, 1996

Greenhouse gas formation

potential

Methylene chloride is degraded to carbon dioxide and hydrogen chloride as major

breakdown products. Therefore some contribution to greenhouse gas is expected.

IPCS, 1996

91

Chemical Properties



Ozone-depletion potential Methylene chloride is not classified as an ozone depleting substance.


Monitoring - has the substance

been found in human or

environmental samples?

In ambient air in rural and remote areas, background levels of 0.07-0.29 µg/m3 have

been measured. In suburban and urban areas levels up to 2 and 15 µg/m3 have been

found.

Concentrations have been reported in the range below 10 µg/L in the surface water of

rivers in industrialized areas and up to 200 mg/L in industrial effluents, outfalls of

municipal water treatment plants and leachates of landfills.

Monitoring data typically fails to discriminate natural Dichloromethane from

industrial.

IPCS, 1996

92

Dichloromethane is of low short term toxicity to humans, however short-term effects as a result of inhalatory

exposure to dichloromethane vapours may cause CNS depression manifested through dizziness and

drowsiness. The substance has been self-classified as STOT SE 3 under CLP with the associated hazard

statement H316: may cause drowsiness or dizziness. Its vapours may cause eye irritation and skin contact

may also cause irritation and has been classified under CLP.

When heated to decomposition dichloromethane will produce phosgene, hydrogen chloride gas, and chlorine

gas which are toxic. In addition, it is metabolised to carbon monoxide, carbon dioxide and inorganic chloride

(HSDB 2010) in the body, which can result in secondary poisoning. Animal data suggests that the substance

may cause liver and lung cancer, while epidemiological data do not support a link of these effects in humans.

However the substance has been classified as Carcinogenic Category 3 under CLP. The SCOEL concluded

that taking together the current knowledge on the potential of human metabolic activation of

dichloromethane, it appears unlikely that this compound poses a practical carcinogenic risk to humans, under

conditions of current occupational exposures. In consequence, SCOEL has decided to assign

dichloromethane to the SCOEL carcinogen group C with a “practical” threshold (Bolt and Huici-Montagud

2008) and to derive an OEL based on non-cancer endpoints5.


Dichloromethane is not a “drop-in” solvent replacement for TRI as noted above. It would mean the

replacing large parts (if not completely) the existing production process and equipment. As per the ECHA

SEA guidance, the lost (book) value of existing equipment is considered a ‘sunk cost’ and therefore not

considered in the analysis. The additional capital and operating costs of making PE SLI battery separators is

however relevant to the assessment of economic feasibility.

A major consideration is the reengineering of processes in order to accommodate the alternative even if it

were technically feasible. This would need to include consideration of solvent recycling and emission

capture. This has not been estimated given the significant technical (feasibility) difficulties. As set out in

Section 6.2, it would take a minimum of 12 years to make a possible alternative solvent suitable. When

comparing the minimum cost of lost profit for 12 years of €116 million NPV (see SEA section

4.2.1 for details on lost profits, but using a discount rate of 7% rather than 4% in the SEA) with the

cost of building additional production lines at the existing US site (in Oregon) which is €48 million

(see Section 4.2.2 of the SEA); which enables ENTEK to avoid any production/sales disruption (i.e. can

provide battery separators to the existing markets after the sunset date), it is clear that switching to

dichloromethane is not economically feasible.

93

The €116 million is considered a minimum costs as it excludes any capital costs as well as some additional

costs like redundancy (over the period 2016-2027) and assumes post 2027, ENTEK can make equivalent

profits. This assumption is however highly unlikely since (i) it assumes ENTEK would not have lost any

market share due to no sales after the sunset date (April 2016) to 2027, and (ii) assumes profit margins would

be similar compared to using TRI. Optimistically factoring in that it would only takes a further 5 years

for ENTEK to recover their market share (i.e. 80% of lost profit in 2024, declining linearly to 0% in

2031) then the net cost to ENTEK is €125 million (NPV). This further reinforces the conclusion

that dichloromethane is not economically feasible.

5.3.5 Availability

Dichloromethane is registered under REACH at the 1,000 tonnes per annum level (Phase 1) and thus can be

assumed to be available to be supplied in the volumes required.

5.3.6 Conclusion on suitability and availability for dichloromethane

As described in Section 3 the R&D process identified that dichloromethane as a potential alternative for TRI.

While initial laboratory and pilot scale trials have been promising, however, there are numerous technical

and economic challenges that need to be evaluated before a final decision can be made on the suitability of

dichloromethane in the ENTEK separator manufacturing process. The large expected capital cost to switch

and loss in profits compared to the costs of building additional production lines in the US, means this

alternative is also not economically feasible.

From an engineering and operations standpoint, the high solubility of dichloromethane in water, its lower

adsorption affinity for activated carbon, and its potential degradation to hydrogen chloride in the presence of

steam are problematic. For example, manufacturers of carbon beds for TRI recovery – a system in which the

solvent routinely contacts steam and water at high temperatures – often recommend stainless steel grade

316L as a material of construction. Carbon bed manufacturers for dichloromethane recovery do not

recommend using 316L Stainless Steel, specifying a more expensive material such as Hastelloy for this

application. The ENTEK-UK plant utilizes 316L Stainless Steel for most of its piping and vessels in which

the extraction solvent becomes in contact with water and steam. Currently, the infrastructure would be at risk

of highly accelerated corrosion and subsequent failure with the use of dichloromethane. Failure of the

structure would pose a significant hazard to human health and the environment in the event of a major

release of dichloromethane.


(dichloromethane) SCOEL/SUM/130, June 2009

94

In addition to the technical challenges it can be seen from Section 4.3.3, that dichloromethane is a hazardous

substance and is classified as such. Although dichloromethane is not a substance of very high concern

(SVHC) it is a suspected carcinogen and subject to an indicative OEL (iOEL) at EU level as well as a

restriction under REACH. The substance would probably represent a reduction in risk, but since there are

concerns for the substance in terms of long term health risks this would have to be taken into consideration in

the further research being done to identify this substance as an alternative along with other substances that

may have a more favourable hazard and risk profile.

95

5.4 TETRACHLOROETHYLENE


Chemical Name(s): tetrachloroethylene

Other names: tetrachloroethene, perchloroethylene, commonly abbreviated to PCE or Perc, 1,1,2,2-

tetrachloroethylene, ethylene tetrachloride, tetrachloro-, Perchloroethene, Per

Trade Name(s): Perstabil®, Ankilostin®, Didakene®,Perclene®, Dowper®,Perklone®



Molecular Formula: C2Cl4

Molecular weight: 165.85


The classifications according to the CLP regulation no. 1272/2008 and according to the Dangerous

Substances Directive 67/548/EEC are presented in the tables below. Both the harmonised classification and

the self-classification as presented in the REACH disseminated dossier registrants are provided.

CLP - according to Regulation No 1272/2008 Annex VI

Classification

area


Physicochemical Not classified Not classified

Health Carc. 2 Carc. 2

Skin Irrit. 2

Skin Sens. 1B

STOT Single Exp. 3.



Environmental Aquatic Chronic 2 Aquatic Chronic 2

Hazard

Statements

H351: Suspected of causing cancer H351: Suspected of causing cancer

96

Classification

area


H315: Causes skin irritation

H317: May cause an allergic skin reaction

H336: May cause drowsiness or dizziness

H411: Toxic to aquatic life with long

lasting effects

H411: Toxic to aquatic life with long lasting

effects

Dangerous Substance Directive – according to Directive 67/548/EEC

Classification

area


Health hazards Carc. Cat. 3; R40 Carc. Cat. 3; R40

R38

Environmental

hazards

R51-53 R51/53

Risk Phrases R40: limited evidence of a

carcinogenic effect

R40: Limited evidence of a carcinogenic effect

R38: Irritating to skin

R51/53: Toxic to aquatic organisms,

may cause long-term adverse effects

in the aquatic environment.

R51/53: Toxic to aquatic organisms, may cause

long-term adverse effects in the aquatic

environment.

Tetrachloroethylene is a colourless, relatively volatile, non-flammable liquid, it is not considered to have

explosive properties and is not subject to auto-ignition. The physicochemical properties of

tertrachloroethylene are summarised in Table 5.7.

Table 5.7 Physico-Chemical Properties of tetrachloroethylene

Properties



Flammability non-flammable EU RAR 2005

Vapour pressure 1.9 kPa at 20°C EU RAR 2005

Boiling point 121.2°C EU RAR 2005

Melting point -22°C EU RAR 2005

Water solubility 149 mg/L EU RAR 2005

javascript:Open_Popup('/clp/ghs/popup_risk.php?no=51/53','pr')






97

Properties



Log Kow 2.53 EU RAR 2005 6


From the research described in Section 3.2 of this document, it appears that tetrachloroethylene may be a

technically feasible alternative to TRI as a process solvent for the manufacture of polyethylene battery

separators. Although it exhibits a slower extraction rate compared to TRI, this property could potentially be

adjusted with temperature of the extraction bath. Further research is required to understand if

tetrachloroethylene could be used at a commercial scale, and to understand whether it would be compatible

with all manufacturing and recovery processes such that the resultant separator meets all customer

requirements. The possible steps to qualify an alternative solvent are described in Section 6.2.


Tetracholoroethylene is classified as a category 2 carcinogen and subject to a SCOEL recommendation for

and occupational exposure limit for the protection of workers at EU level7. The iOEL is summarised as

follows:


STEL (15 min): 40 ppm [275 mg/m3]

BLVs (biological limit value): 0.4 mg tetrachloroethylene/l blood

3 ppm [0.435 mg/m3] tetrachloroethylene in end-exhaled air

SCOEL carcinogen group: D (non-genotoxic carcinogen with threshold)

Notation: ‘skin’


6 European Union Risk Assessment Report. Tetrachloroethylene, Part I – Environment, CAS No: 127-18-4, EINECS

No: 204-825-9 European Chemicals Bureau, 1st Priority List, volume 57. EUR 21680 EN. Final Report 2005, United

Kingdom

7 Recommendation from the Scientific Committee on Occupational Exposure Limits on Tetrachloroethylene

(perchloroethylene) SCOEL/SUM/133, June 2009

98

Table 5.8 hazard profile of tetrachloroethylene

Chemical Properties Characteristics of Chemical



Acute toxicity Acute toxicity in humans resulting from ingestion or inhalation resulted in

neurological effects such as dizziness, fatigue, coma, some deaths

(concentration unknown), kidney dysfunction, reversible liver damage.

Irritation of the respiratory tract following inhalation has also been observed.

ATSDR (1997)

IRIS (2012)

WHO (2006)

Acute toxicity in animals is low, effects are only reported at high concentrations

of oral or inhalation exposure to tetrachloroethylene. Effects include depression

of Central Nervous System (CNS), effects on liver, kidneys, and spleen; lung

hemorrhages were also observed in deceased rats.

ATSDR (1997)

IRIS (2012)

ECHA (2013)

Skin or eye

corrosion/irritation

Tetrachloroethylene was highly irritating to the eyes of humans following acute

exposure to a high dose of the vapours (930 ppm). While burning or stinging of

the eyes occurred at doses of 600 or 280 ppm, at 216 or 106 ppm the substance

was only very mildly irritating to a few volunteers.

Dry cleaning workers exposed to 20 ppm on average for 8 hours complained of

irritation.

SCOEL (2009)

Tetrachloroethylene is a skin irritant in humans, causing reddening and

blistering. Effects may persist for months after severe exposure has occurred.

SCOEL (2009)

Respiratory or skin

sensitization

Tetrachloroethylene has been demonstrated to be a weak dermal sensitizer in

animals, and is self-classified as a skin sensitiser. NEG-DECOS (2003) describe

two case reports of tetrachloroethylene skin sensitisation in humans.

ECHA, 2013

SCOEL (2009)

Chronic toxicity

Carcinogenicity Occupational exposure studies with dry cleaning workers show associations

between exposure to dry cleaning solvents and certain types of cancer, in

particular: bladder, multiple myeloma, kidney, oesophagus, cervix, breast, and

IRIS, 2012

WHO (2006)

99



non-Hodgkin’s lymphoma. However some of the cancer associations with

tetrachloroethylene are weak and the studies are confounded as the workers

were exposed to multiple solvents. In addition, the exposure concentrations and

initial health status were not clear.

In animals there is clear evidence that tetrachloroethylene is carcinogenic.

Inhalation exposure to rats caused leukaemia and kidney tumours, while

inhalation exposure to mice caused liver tumours. Oral exposure to mice caused

liver tumours.

IRIS (2012)

WHO (2006)

Long term toxicity The main effects on humans and animals from long-term exposure to

tetrachloroethylene are neurotoxicological effects.

Occupational exposure levels for tetrachloroethylene have been typically around

100 ppm, although currently lower. The target organs are the CNS, liver, and

kidneys.

Generally, no clear effects on the kidney or the liver of humans were seen at

concentrations below 50 ppm.

WHO (2006)

IRIS (2012)

SCOEL (2009)

Mutagenicity Overall, tetrachloroethylene is not considered to be mutagenic.

The majority of the in vitro studies conducted with liquid and vapour phase

tetrachloroethylene conclude that tetrachloroethylene is not genotoxic.

EU RAR (2005)

WHO (2006)

SCOEL (2009)

Neurotoxicity A large number of studies and epidemiological data are available assessing the

neurotoxicological and behavioural effects of tetrachloroethylene on humans

and rats.

In humans, long-term inhalation of tetrachloroethylene caused neurological

effects such as sensory symptoms (headaches, dizziness) and impairment of

cognitive and neurobehavioural functioning and colour visions decreases.

IRIS, 2012

Immune system toxicity Mild microcytic anemia and bone marrow and immune function changes

occurred in mice exposed via drinking water to tetrachloroethylene

plus 24 other groundwater contaminants

Germolec et al., 1989

Systemic toxicity Chronic inhalation exposure to 100 ppm resulted in kidney and lung effects in

mice.

NTP, 1986

ATSDR, 1997

100



Toxic metabolites In humans, the substance is mainly exhaled as tetrachloroethylene (95%), and

the remainder excreted in the urine as trichloroacetic acid. Certain toxic

metabolites were not detectible during metabolism of tetrachloroethylene in

humans. In animals, excess tetrachloroethylene can lead to the formation of

cytotoxic and genotoxic metabolites.

WHO (2006) and SCOEL (2009)

Reproductive/developmental There are limited data from studies with significant confounders (e.g, no/limited

exposure information; lack of consideration of recognized risk factors)

describing relatively weak associations between occupational exposure to

tetrachloroethylene and spontaneous abortions and disruption of menstrual

cycle.

Based on a guideline 2-generation inhalation rat study, tetrachloroethylene is not

considered a fertility or reproductive toxicant, as maternal toxicity likely

affected the fertility parameters (reductions in litter size and pup survival at

1000 ppm, and pup body weight at 1000 and 300 ppm). The maternal NOAEL

of 250 ppm from a guideline inhalation developmental toxicity study in rats

corresponded with the developmental NOAEL; slight reductions in fetal weight

and some fetal variations were within historical control values.

SCOEL (2009)

ECHA, 2013

IRIS (2012)

Drinking water contaminated with tetrachloroethylene and other chlorinated

hydrocarbons has been associated with birth defects, however the exposure was

to a mixture of chemicals, therefore a direct link to tetrachloroethylene cannot

be drawn.

IRIS (2012)

SCOEL (2009)


Acute aquatic toxicity In short-term toxicity studies on three trophic levels with tetrachloroethylene

effects have been found in the range 1-10 mg/L, with algae being the most

sensitive.

ECHA 2013

Chronic aquatic toxicity In long-term toxicity studies on three trophic levels with tetrachloroethylene the

most sensitive species was Daphnia magna with a 28 day NOEC 0.51 mg/L

based on reproduction.

ECHA 2013

Terrestrial toxicity Tetrachloroethylene has been tested with various terrestrial organisms, however

due to volatilisation of the substance maintaining exposure concentrations was

considered to be difficult. Studies where a lack of effect took place may be due

to the substance evaporating from test medium.

ECHA 2013

101



Effects have been reported in the range of a NOEC <0.1 mg/kg based on

nitrification with loam to 14 day LC50 945 mg/kg with earthworms.

Bioaccumulation Tetrachloroethylene has a low potential for bioaccumulation based on a

measured BCF in fish of 40-50 l/kg w. wt. and low log Kow.

ECHA 2013

Persistence Tetrachloroethylene is not readily biodegradable (0% degradation in 21 days).

However the substance is subject to anaerobic degradation, through reductive

dechlorination. Its degradation products are TRI, dichloroethylene, vinyl

chloride, ethene and ethane.

Tetrachloroethylene will evaporate from moist mediums. In soil and sediment,

the substance’s adsorption potential (high Koc 665) indicates that some

persistence is possible.

ECHA (2013), EU RAR (2005)

EU RAR (2005)


potential

Tetrachloroethylene is not expected to significantly contribute to global

warming.

EU RAR (2005)

Ozone-depletion potential Tetrachloroethylene will degrade to substance which may enter the stratosphere,

carbon tetrachloride is the only known ozone depleting degradation product,

however the contribution of carbon tetrachloride from degradation of

tetrachloroethylene is considered negligible.

Overall the substance is not considered to have ozone depleting potential.

EU RAR (2005)

Tetrachloroethylene is not classed as an ozone depleting substance.


102

The main form of toxicity of the tetrachloroethylee is expressed through inhalation of its vapours, where the

substance can produce irritating effects to the eyes, lungs and at high enough concentrations dysfunction of

the Central Nervous System (CNS) in humans. It has been self-classified under CLP as Skin Irritant 2, as a

Skin Sensitiser 1B and as STOT SE 3, affecting the CNS through inhalation.

Overall, the SCOEL states that there are no clear repeated dose toxicity effects in humans exposed up to 25

ppm (173 mg/m3) tetrachloroethylene.

Tetrachloroethylene is classified as a possible carcinogen. The human evidence of its carcinogencity is

limited due to the presence of other solvents in exposure to humans data. However the substance is positively

carcinogenic in animal studies. It is classified as Carcinogenic 2 in the CLP. The NTP classified the

substance as “reasonably anticipated to be a human carcinogen”, while the SCOEL carcinogen group is D

(non-genotoxic carcinogen with threshold).

Tetrachloroethylene is toxic to aquatic and terrestrial organisms, with long-term effects reported with

Daphnia magna, 21-d NOEC 0.51 µg/L, and nitrification effects observed with Loam, a NOEC of ≤1 mg/kg

wwt has been derived. Tetrachloroethylene is classified under CLP as Aquatic Chronic 2.

PBT and CMR

Tetrachloroethylene does not fulfil the PBT criteria, because it does not fulfil the B and T criteria. It does

however fulfill the T criterion based on its classification as Carcinogenic 2 under CLP.

The substance is considered a CMR because it is classified as Carcinogenic 2.

Tetrachloroethylene is being assessed in the CoRAP program because it is a CMR agent, a suspected PBT, it

has wide and dispersive use with a high risk of exposure in the workplace, and a high aggregated tonnage in

the EU.


Tetrachloroethylene is not a “drop-in” solvent replacement for TRI as noted above. It would mean the









103

comparing the minimum cost of lost profit for 12 years of €116 million NPV (see SEA section 4.2.1

for details on lost profits, but using a discount rate of 7% rather than 4% in the SEA) with the cost

of building additional production lines at the existing US site (in Oregon) which is €48 million (see

Section 4.2.2 of the SEA); which enables ENTEK to avoid any production/sales disruption (i.e. can provide

battery separators to the existing markets after the sunset date), it is clear that switching to

tetrachloroethylene is not economically feasible.








that tetrachloroethylene is not economically feasible.

5.4.5 Availability

Tetrachloroethylene is registered under REACH at a tonnage band of 100,000 to 1,000,000 tonnes per

annum level and thus can be assumed to be available to be supplied in the volumes required.

5.4.6 Conclusion on suitability and availability for tetrachloroethylene

As described in Section 3 the R&D process identified that tetracholoroethylene could be a potential

alternative for TRI. While initial laboratory trials show promise, there are numerous technical and economic

challenges that need to be evaluated before a final decision can be made; on the suitability of

tetrachloroethylene in the ENTEK separator manufacturing process. Further detail of the possible steps that

would need to be taken and the timing associated with those steps is described in section 5.

The large expected capital cost to switch and loss in profits compared to the costs of building additional

production lines in the US, means this alternative is also not economically feasible.

From an engineering and operations standpoint, the exceedingly low solubility of tetrachloroethylene in

water and its low vapour pressure could be advantageous in the areas of solvent containment and worker

exposure. The lower oil extraction rate of tetrachloroethylene can potentially be addressed by heating the

solvent. Nevertheless, further work is required to determine the impact of the higher extraction temperature

and boiling point on energy costs for separator manufacturing and solvent recovery.

104

In addition to the technical challenges it can be seen from Section 4.4.3 above that tetrachloroethylene is a

hazardous substance and is classified as such. Although tetrachloroethylene is not a substance of very high

concern it is a suspected carcinogen and subject to an indicative OEL (iOEL) at EU level. The substance

was evaluated under REACH in the Community Rolling Action Plan (CoRAP) due to concerns for human

health/CMR; environment/suspected PBT; exposure/wide dispersive use and aggregated tonnage (although

no further action to control risks was indicated). The substance would probably represent a reduction in risk

in respect of emissions control, but since there are concerns for the substance in terms of long term health

hazards this would have to be taken into consideration in the further research being done to identify this

substance as an alternative, along with other substances that may have a more favourable hazard and risk

profile.

105

5.5 VERTREL® SDG

Vertrel® SDG is the trade name of a chemical produced by DuPont. It has not been registered in the EU and

there is generally little information available on the substance outside of the information given in the two

Material Safety Data Sheets available online. Vertrel® SDG is a mixture and additional information is

available on its constituents (see Table 4.13).


Vertrel® SDG is a mixture of non-flammable hydrofluorocarbons (HFCs) and trans-1,2-dichloroethylene (t-

DCE). Summary data for Vertrel® SDG is set out in Table 5.9 below.

Table 5.9 Composition of Vertrel® SDG.

Substance name CAS # Concentration

trans-dichloroethylene 156-60-5 65 - 90 %

1,1,1,2,2,3,4,5,5,5-decafluoropentane 138495-42-8 5 - 25 %

1,1,2,2,3,3,4-heptafluorocyclopentane 15290-77-4 5 - 15 %

The compositional information has been taken from the most recent available MSDS sheet, dated 2012.


A classification and labelling for the substance mixture is not available.

The human health and environmental harmonised classifications for the constituents in Vertrel® SDG

according to the CLP regulation no. 1272/2008 and to the Dangerous Substances Directive 67/548/EEC are

presented in the tables below, where available.

Trans-dichloroethylene, CAS 156-60-5

Classification area CLP - according to Regulation No

1272/2008 Annex VI




Health Acute Tox 4 Xn; 20

Environmental Aquatic Chronic 3 R52/53

Hazard Statements H225: Highly flammable liquid and

vapour

11: Highly flammable

H332: harmful if inhaled 20: Harmful by inhalation

106


1272/2008 Annex VI



H412: harmful to aquatic life with long

lasting effects

52/53: Harmful to aquatic organisms, may


aquatic environment.

1,1,1,2,2,3,4,5,5,5-Decafluoropentane, CAS 138495-42-8

No harmonized classification and labelling exists for decafluoropentane. The classification and labelling

reported in the ECHA disseminated dossier have been presented instead.

Classification area CLP - according to 1272/2008 Annex

VI – disseminated dossier


according to Directive 67/548/EEC –

disseminated dossier


Health Aquatic Chronic 3 R52/53


Hazard Statements H412: harmful to aquatic life with long

lasting effect

R52/53: Harmful to aquatic organisms,

may cause long-term adverse effects in the


1,1,2,2,3,3,4-Heptafluorocyclopentane, CAS 15290-77-4


1272/2008 Annex VI




Health Not classified Not classified

Environmental Aquatic Chronic 3 R52/53

Hazard Statements H412: harmful to aquatic life with long

lasting effects

52/53: Harmful to aquatic organisms, may



The physico-chemical properties of Vertrel® SDG were previously listed in Table 4.3 and compared to TRI

and other alternatives that have been investigated by ENTEK.

107

Table 5.10 Physico-Chemical Properties of Vertrel® SDG

Properties



Flammability Does not flash. No flash point was obtained, but

the product may release flammable vapour.

DuPont, MSDS 2012

Vapour pressure 51.7 kPa at 25˚C DuPont, MSDS 2012

Boiling point 43°C DuPont, MSDS 2012

Melting point N/A

Water solubility Slightly soluble DuPont, MSDS 2007

Log Kow N/A

Vertrel® SDG is a clear liquid with a slightly ether-like odour. It is slightly soluble in water (not quantified)

and is very volatile. The vapours are said to be heavier than air. [DuPont, MSDS 2012]

Table 5.11 Physico-Chemical Properties of the constituents of Vertrel® SDG

Properties

trans-Dichloroethylene (CAS

156-60-5)

1,1,1,2,2,3,4,5,5,5-

Decafluoropentane

(CAS 138495-42-8)

1,1,2,2,3,3,4-

Heptafluorocyclopentane

(CAS 15290-77-4)

EC Number 205-860-2 420-640-8 430-710-1

Molecular

Formula

C2H2Cl2 C5H2F10 N/A

Molecular Weight 96.94 g/ml

[MSDS 2013, Sigma-Aldrich]

252.05 N/A

Flammability Highly flammable

[NTP 2002]

Not flammable, based on

Flash point >70˚C

[ECHA 2013]

Not flammable, based on Flash

point ≥82.5˚C

[ECHA 2013]

Vapour pressure 44 kPa at 25˚C

[HSDB 2012]

31.3 kPa at 25˚C

[ECHA 2013*]

1.6 kPa at 20˚C

[ECHA 2013]

Boiling point 48.4˚C

[NTP 2002]

53.2-54.2°C

[ECHA 2013*]

82.5°C

[ECHA 2013]

Melting point -50˚C

[NTP 2002]

-84°C

[ECHA 2013*]

20.5°C

[ECHA 2013]

Water solubility 630 mg/L

[NTP 2002]

126 ± 33 mg/L

[ECHA 2013*]

717 mg/L

[ECHA 2013]

Log Kow 2.06

[NTP 2002]

2.7

[ECHA 2013*]

2.4

[ECHA 2013]

* The data are for the substance: Reaction mass of (3R,4R)-1,1,1,2,2,3,4,5,5,5-decafluoropentane and (3S,4S)- 1,1,1,2,2,3,4,5,5,5-

decafluoropentane, CAS 138495-42-8, EC 420-640-8

http://apps.echa.europa.eu/registered/data/dossiers/DISS-a211562f-c38b-0b1d-e044-00144f67d031/AGGR-c602834c-9bb2-449e-b817-6f09640753b0_DISS-a211562f-c38b-0b1d-e044-00144f67d031.html#GEN_RESULTS_HD

http://apps.echa.europa.eu/registered/data/dossiers/DISS-a211562f-c38b-0b1d-e044-00144f67d031/AGGR-c602834c-9bb2-449e-b817-6f09640753b0_DISS-a211562f-c38b-0b1d-e044-00144f67d031.html#GEN_RESULTS_HD

108


As discussed in Section 3.2.1, Vertrel® SDG appears to be an effective solvent for naphthenic process oils

and the resultant separators have properties that are similar to the TRI-extracted separators. There are

however major obstacles to the use of Vertrel® SDG as an alternative solvent in the ENTEK continuous

separator manufacturing process. Vertrel® SDG is highly volatile with a boiling point of only 43°C. As such,

ENTEK would need to efficiently contain and recover this solvent in its separator manufacturing operation.

The ability to adsorb and desorb the Vertrel° SDG chemical components from a carbon bed is unknown.

This solvent is often used in degreasing applications with the vapours released to the atmosphere. As such,

there has been little work on the efficient recovery of this solvent. In addition, due to the volatility and

vapour pressure of this substance there are likely to be much more evaporative losses (compared to TRI).

This would mean re-assessment and reengineering of emission capture and recycling in order to recycle the

substance and to control releases.

While initial laboratory trials showed promise, there are numerous technical challenges that need to be

evaluated before a decision could be made on the suitability of Vertrel® SDG in the ENTEK continuous

separator manufacturing process. From engineering and operations standpoints, the significantly higher

vapour pressure, the high solubility of Vertrel® SDG in water, its unknown adsorption affinity for activated

carbon, and potential degradation of its chemical components in the presence of steam are problematic.


Table 5.12 below summarises further information on the hazard profile of the substance. Tables 5.13 to 5.15

summarise the available data on the hazard properties of Vertrel® SDG constituents. These have been

presented because the data for the mixture is poor and because from a risk point of view, once the substance

is released into the environment the properties of its individual constituents will determine the fate.

109

Table 5.12 Hazard profile of Vertrel® SDG

Chemical Properties Characteristics of Chemical Source(s) of Information


Acute toxicity Inhalation of high doses may cause cardiac arrhythmia, Central Nervous System

(CNS) effects and convulsions. Effects may include tiredness or drowsiness.

DuPont, MSDS 2012

Ingestion may cause pulmonary edema (body fluid in the lungs) and respiratory

distress.

Ingestion may also cause pathological changes in the liver and CNS depression.

[Information taken from the DuPont, MSDS sheet dated 2007; which is not presented

in the 2012 MSDS sheet.]

DuPont, MSDS 2007

Skin or eye corrosion/irritation Skin contact may cause severe irritation with burning, redness, swelling, pain or rash.

Eye contact may cause severe eye irritation with tearing, pain or blurred vision.

DuPont, MSDS 2007

Carcinogenicity No data available, however none of the constituents are classified as carcinogens. DuPont, MSDS 2007



potential

Low global warming potential.

No further information on its degradation products is available.

DuPont, Technical sheet 2008

Ozone-depletion potential Zero ozone depletion potential.

The substance has not been classified as an ozone depleting substance.

DuPont, Technical sheet 2008


110

Table 5.13 Hazard profile of trans-dichloroethylene – constituent (65-90% of total)



Acute Toxicity

Acute toxicity Inhalation 4 h LC50: 96.4 mg/l in rat, CNS effects observed. DuPont, MSDS 2012

Inhalation (duration unspecified) LC50: 2.2*105 mg/m3. NTP 2002

Not acutely toxic via oral or dermal administration DuPont, MSDS 2012

Skin or eye corrosion/irritation Skin irritant and mild eye irritant in rabbits.

1,2-Dichloroethylene can cause eye and skin irritation.

However it is not classified as a skin or eye irritant under CLP.

DuPont, MSDS 2012

HSDB, 2012

Respiratory or skin

sensitization

Cardiac sensitisation threshold limit: 7.9*105 mg/m3

However it is not classified as a sensitising agent under CLP.

DuPont, MSDS 2012

Chronic Toxicity

111


Long term toxicity Oral – rat 90 d study: No toxicologically significant effects were found.

Inhalation – rat. 90 d study: No toxicologically significant effects were found.

No further details are available.

DuPont, MSDS 2012

Generally, little toxicity is observed with ingestion of microencapsulated trans-1,2-

dichloroethylene.

NTP, 2002

Reproductive/developmental Animal testing showed no reproductive or developmental toxicity. No further details

are available.

Toxicity to the dams was not observed at concentrations below maternal toxicity

(6000 ppm).

DuPont, MSDS 2012

NTP, 2002

Mutagenicity Not genotoxic in vitro and in vivo DuPont, MSDS 2012 and NTP, 2002

Neurotoxicity trans-1,2-Dichloroethylene has been shown to cause central nervous system effects in

humans, characterized by dizziness, drowsiness, vertigo, and increased intracranial

pressure (ATSDR, 1990). CND depression has not been observed in chronic toxicity

studies with rats and mice.

NTP, 2002

Immune system toxicity Suppression in humoral immune status and decreased macrophage induction NTP, 2002


112


Acute/chronic aquatic toxicity Acute fish and Daphnia toxicity: 10-100 mg/l, algae >100 mg/l

DuPont, MSDS 2012

Bioaccumulation Bioaccumulation potential is low

DuPont, MSDS 2012 and HSBD, 2012

Persistence Readily biodegradable

Not readily biodegradable. However 73% of the substance was lost in 6 months under

anaerobic conditions, forming vinyl dichloride.

DuPont, MSDS 2012

HSDB, 2012

Vapour-phase trans-1,2-dichloroethylene will degrade in the atmosphere by reaction

with photochemically-produced hydroxyl radicals; the half-life in air is estimated to be 6.9 days.

HSDB, 2012

Ozone depleting potential The vapour-phase trans-dichloroethylene has an atmospheric half-life of about 320

days at an atmospheric concentration of 7*1011

ozone molecules per cu cm.

HSDB, 2012

Monitoring - has the substance

been found in human or

environmental samples?

1,2-Dichloroethylene has been detected in groundwater at concentrations up to 3

900 μg/L and in drinking water at concentrations from none to 2 277 μg/L.

NTP, 2002 and HSBD, 2012

113

Table 5.14 Hazard profile of 1,1,1,2,2,3,4,5,5,5-decafluoropentane – constituent (5-25% of total)



Acute toxicity Oral LD50 >5000 mg/kg bw

Inhalation 4 h LC50 114 428 mg/m3 (11 100 ppm)

Dermal LD50 >5000 mg/kg bw

ECHA, 2013

Inhalation 4 h LC50 114 mg/l , rat. Central nervous system effects. Convulsions

Not acutely toxic via oral or dermal administration

DuPont, MSDS 2012

Skin or eye corrosion/irritation Not a skin or eye irritant. DuPont, MSDS 2012 and ECHA, 2013

Long term toxicity In an inhalation toxicity study with rats (duration unknown), no toxicologically

significant effects were found.

14 week NOAEL with rats: 500 ppm based on clinical signs of central nervous

system toxicity.

DuPont, MSDS 2012

ECHA, 2013

Mutagenicity No genotoxicity found in vitro and in vivo DuPont, MSDS 2012

Respiratory or skin

sensitization

Did not cause sensitisation in guinea pig.

The substance has not been classified as a sensitising agent.

DuPont, MSDS 2012

ECHA, 2013

Neurotoxicity The NOAEL for CNS effects in rats has been determined at 15 463 mg/m3. ECHA, 2013

Reproductive/developmental Animal testing showed no reproductive or developmental toxicity.

No further information provided.

DuPont, MSDS 2012

The NOAEL for reproduction was ≥3500 ppm (36081 mg/m3) in rats exposed for 90

days.

ECHA, 2013

114


The NOAEL for developmental toxicity was determined at 2000 ppm (20 618

mg/m3), based on litter weight effects.


Acute/chronic aquatic toxicity Fish and Daphnia acute: 10-100 mg/l, algae >100 mg/l

Chronic daphnia: 1.72 mg/l

DuPont, MSDS 2012 and ECHA, 2013

Bioaccumulation Bioaccumulation is unlikely for decafluoropentane. DuPont, MSDS 2012

Persistence Not biodegradable.


The atmospheric half-life has been determined at 23 years, through reaction with OH. ECHA, 2013


potential

The 100 year Global Warming Potential is 1640 (compared to a GWP of 34 for

methane).

ECHA, 2013

Ozone-depletion potential The substance has not been classified as an ozone depleting substance.


115

Table 5.15 Hazard profile of 1,1,2,2,3,3,4-heptafluorocyclopentane – constituent (5-15% of total)



Acute toxicity Inhalation 4 h LC50 ca. 115 mg/l, rat

Oral and dermal: non toxic


Skin or eye corrosion/irritation Skin irritation: non-irritant, Eye irritation: non-irritant DuPont, MSDS 2012 and ECHA, 2013

Long term toxicity Oral, rat: No toxicologically significant effects were found.

Inhalation, rat: No toxicologically significant effects were found.

DuPont, MSDS 2012

Oral NOAEL 1000 mg/kg bw/day, NOEL <15 mg/kg bw/day

Inhalation NOAEL 2.85 mg/L air, NOEC <2.85 mg/L air

ECHA, 2013

Mutagenicity Not genotoxic in vitro DuPont, MSDS 2012

Respiratory or skin

sensitization

Not sensitising DuPont, MSDS 2012 and ECHA, 2013

Cardiac sensitization was investigated in dogs, however results are not available. ECHA 2013


Acute/chronic aquatic toxicity Fish, daphnia and algae acute: 10-100 mg/l

Algal 72 h NOEC: 25 mg/L

DuPont, MSDS 2012

and ECHA, 2013

Bioaccumulation No data DuPont, MSDS 2012

Persistence 0% degradation in 28 d

ECHA, 2013

116

Limited information is available on the hazard profile of Vertrel® SDG. Upon combustion the substance can

degrade to toxic substance such as hydrogen fluoride, fluorinated hydrocarbons, carbonyl fluoride, carbon

oxides and hydrogen chloride. The DuPont, MSDS (2012) sheet indicates that vapours are heavier than air

and can cause suffocation by reducing oxygen available for breathing.

The short-term exposure to high levels of Vertrel® SDG may cause effects to the central nervous system

(CNS) with symptoms including tiredness and drowsiness, changes to the heartbeat frequency and regularity

and convulsions. The substance itself does not have a harmonised classification and labelling nor is it

classified in its MSDS, however one of its constituents, trans-dichloroethyle (CAS 156-60-5, 65-90% of total

substance) is classified as Acute Toxicity 4. For this constituent effects to the CNS have been been observed

in rats. Effects to the CNS have also been observed in acute inhalation studies with the 1,1,1,2,2,3,4,5,5,5-

decafluoropentane (5-25% of total substance).

The substance is said to cause severe eye and skin irritation upon contact, and its constituents are described

as mild irritants.

The substance and some of its constituents cause cardiac sensitisation however neither are classified as such.

Data available on the constituents of Vertrel® SDG, indicate that they are not considered as readily

biodegradable substances and in short-term ecotox studies effects are reported in the range 10-100 mg/l. In

fact, where classification is reported, they are classified as Aquatic Chronic 3 under CLP.


It is understood that this material is currently some 40-50 times the cost of TRI. This is prohibitively

expensive. In addition, based upon laboratory testing results, Vertrel° SDG would result in less separator

shrinkage than occurs with TRI. This difference would result in all calender tools needing to be re-cut with a

new groove pattern to end up with a final separator having the desired profile. ENTEK has 43

calender/profile rolls (also known as tools) at its UK plant that would need to be re-machined. The time

period to convert all of these tools would be at least two years at an estimated cost of € 1.2 million.

Furthermore, a major consideration is the reengineering of processes in order to accommodate the alternative

even if it were technically feasible. This would need to include consideration of solvent recycling and

emission capture since the volatility of the substance is quite different from TRI.

Vertrel® SDG is not a “drop-in” solvent replacement for TRI, as noted above. It would mean the replacing

large parts (if not completely) the existing production process and equipment. As per the ECHA SEA

guidance, the lost (book) value of existing equipment is considered a ‘sunk cost’ and therefore not



117









battery separators to the existing markets after the sunset date), it is clear that switching to Vertrel® SDG is

not economically feasible.








that Vertrel® SDG is not economically feasible.

5.5.5 Availability

The product that is a substance mixture is commercially available.

5.5.6 Conclusion on suitability and availability for Vertrel® SDG

As described in Section 4.2 the R&D process identified that Vertrel® SDG is a potential alternative for TRI.

While initial laboratory trials show promise, there are numerous technical and economic challenges that need

to be evaluated before a decision can be made on the suitability of Vertrel® SDG in the ENTEK separator

manufacturing process.



From an engineering and operations standpoint, a significantly higher vapour pressure, the high solubility of

Vertrel® SDG in water, its unknown adsorption affinity for activated carbon, and potential degradation of its

chemical components in the presence of steam are problematic. From a hazard point of view, there is very

118

limited information on the substance, however. based on the available information it seems likely that the

substance will possess similar hazard properties to other solvents, since effects to the CNS and some

irritation potential have been observed. Extensive further testing would be required to ensure that the use

Vertrel® SDG would not pose similar hazard and risk levels compared to the continued use of TRI.

119

5.6 HFE-72DE


HFE-72DE is a mixture of 1,2-trans-dichloroethylene, ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl

ether, methyl nonafluoroisobutyl ether and methyl nonafluorobutyl ether, produced by 3M™ Novec™.

Table 5.16 Composition of HFE-72DE.

Substance name CAS # Concentration

trans-dichloroethylene 156-60-5 68-72%

ethyl nonafluoroisobutyl ether 163702-06-5 4-16%

ethyl nonafluorobutyl ether 163702-05-4 4-16%

methyl nonafluoroisobutyl ether 163702-08-7 2-8%

methyl nonafluorobutyl ether 163702-07-6 2-8%

The compositional information has been taken from the most recent available MSDS sheet, dated 2007.


A classification and labelling for the substance mixture is not available, A harmonised classification for

trans-dichloroethylene is available and has been reported in Table 4.1. No other harmonisation

classifications for the other constituents of HFE-72DE are available.

Based on the information reported on the ECHA pages, only notified classifications and labelling (3

aggregated) according to the CLP regulation no. 1272/2008 are available for the ethyl nonafluorobutyl

constituent of HFE-72DE (no notifications are available relating to classification according to the Dangerous

Substances Directive 67/548/EEC):

120

Ethyl nonafluoroisobutyl ether, CAS 163702-06-5

Classification area CLP - according to Regulation No 1272/2008

Annex VI

Phsyicochemica Not classified

Health Eye Irrit. 2

Environmental Aquatic Chronic 4

Hazard Statements H319: causes serious eye irritation

H412: may cause long lasting harmful effects to

aquatic organisms

Table 5.17 Physico-Chemical Properties of HFE-72DE

Properties

Characteristics of Chemical Source(s) of Information

Flammability LEL 6.7%

UEL 13.7%

3M, MSDS 2007

Vapour pressure 44kPa at 25 ºC 3M, MSDS 2007

Volatility Very volatile 3M, MSDS 2007

Boiling point 45˚C 3M, MSDS 2007

Melting point Not applicable 3M, MSDS 2007

Water solubility Negligible 3M, MSDS 2007

HFE-72DE is described as a clear, colourless liquid with a slight odour. Its use is intended as an industrial

only cleaning and coating solvent.


As discussed in Section 3.2.1, HFE-72DE is an effective solvent for naphthenic process oils and the resultant

separators have properties that are similar to the TRI-extracted separators. There are major obstacles to the

use of HFE-72DE as an alternative solvent in the ENTEK separator manufacturing process:

HFE-72DE is expensive and highly volatile with a boiling point of only 43 °C. As such, ENTEK would

want to efficiently contain and recover this solvent in its separator manufacturing operation. The ability to

adsorb and desorb the HFE-72DE chemical components from a large scale carbon bed system has not been

demonstrated. This solvent is often used in degreasing applications with the vapours released to the

atmosphere. As such, there has been little work on the efficient recovery of this solvent.

121

While initial laboratory trials showed promise, there are numerous technical challenges that need to be

evaluated before a decision could be made on the suitability of HFE-72DE in the ENTEK separator

manufacturing process. From engineering and operations standpoints, a significantly higher vapour pressure,

the high solubility of HFE-72DE in water, its unknown adsorption affinity for activated carbon, and potential

degradation of its chemical components in the presence of steam are problematic.


Table 5.18 below summarises further information on the hazard profile of the substance as the whole

substance or of the constituents where available. The hazard profile of trans-dichloroethylene is presented in

Table 5.13.

122

Table 5.18 hazard profile of HFE-72DE


Acute toxicity HFE-72DE is considered non-toxic by inhalation based on a 4-hour inhalation

study in rats (4-hour LC50 greater than 20 mg/L).

If thermal decomposition occurs: May be harmful if inhaled.

May be absorbed following inhalation and cause target organ effects.

MSDS (2007) – all

Skin or eye corrosion/irritation Moderate Eye Irritation

Moderate Skin irritation

Respiratory Tract Irritation: Signs/symptoms may include cough, sneezing, nasal

discharge, headache, hoarseness, and nose and throat pain.

MSDS (2007)

Carcinogenicity No data

Target Organ toxicity May cause target organ toxicity. Central Nervous System (CNS) Depression:

Signs/symptoms may include headache, dizziness, drowsiness, incoordination,

nausea, slowed reaction time, slurred speech, giddiness, and unconsciousness.

MSDS (2007)

Neurotoxicity Yes, see above

Respiratory or skin

sensitization

Cardiac Sensitization: Signs/symptoms may include irregular heartbeat (arrhythmia),

faintness, chest pain, and may be fatal.

MSDS (2007)

Toxic metabolites? N.A. but at elevated temperatures – extreme conditions of heat, the substance may

decompose into the following hazardous by-products:

Hydrogen chloride

Hydrogen fluoride

Perfluoroisobutylene (PFIB)

MSDS (2007)


Acute/chronic aquatic toxicity Testing results indicate that ethyl nonafluoroisobutyl ether, ethyl nonafluorobutyl

ether, methyl nonafluoroisobutyl ether and methyl nonafluorobutyl ether have

insignificant toxicity to aquatic organisms at their saturation point (Lowest LC50,

MSDS (2007)

123

EC50, or IC50 >substance water solubility). MSDS (2007)

Bioaccumulation The majority of the constituents ares said to be unlikely to bioaccumulate based on

their volatilization properties. MSDS (2007)

Persistence No data on biodegradation. However they state: These compounds are highly volatile

and have high Henry's Law constants and are thus expected to move rapidly through

vaporization from solution in an aquatic compartment or from a soil surface in a

terrestrial compartment to the atmosphere.

MSDS (2007)


potential

Global Warming Potential (GWP): 320 (100 year ITH, WMO 1998 method) for

methyl nonafluoroisobutyl ether and methyl nonafluorobutyl ether; 55 (100-yr ITH)

for ethyl nonafluoroisobutyl ether and ethyl nonafluorobutyl ether using the

calculation method outlined in Climate Change 2001; and essentially zero for 1,2-

trans-dichloroethylene.

GWP of product as formulated: approximately 43 (100-yr ITH).

MSDS (2007)

Ozone-depletion potential The substance has not been classified as an ozone depleting substance. The MSDS

sheet indicates that the substance has zero ozone depleting potential. Regulation (EC) No 2037/2000

and MSDS (2007)

124

Limited information is available on the hazard profile of HFE-72DE. Upon combustion the substance can

degrade to toxic substance such as hydrogen fluoride, hydrogen chloride and perfluoroisobutylene.

The short-term exposure to high levels of HFE-72DE may cause effects to the central nervous system (CNS)

with symptoms including dizziness, drowsiness, slowed reaction times and unconsciousness. The substance

itself does not have a harmonised classification and labelling nor is it classified in its MSDS, however one of

its constituents, trans-dichloroethylene (CAS 156-60-5, 68-72% of total substance) is classified as Acute

Toxicity 4. For this constituent effects to the CNS have been also been observed with rats.

HFE-72DE is said to cause mild eye and skin irritation upon contact, and its constituents are described as

mild irritants. The substance is also said to potentially cause irregular heartbeats and chest pain although it is

not classified as a respiratory sensitising agent.

The fluoro based constituents are said to not be toxic in short-term aquatic toxicity tests up to their limit of

solubility.


It is understood that this material is currently some 40-50 times the cost of TRI. In addition, based upon

laboratory testing results, HFE-72DE would result in less separator shrinkage than occurs with TRI. This

difference would result in all calender tools needing to be re-cut with a new groove pattern to end up with a

final separator having the desired profile. ENTEK has 43 calender/profile rolls (also known as tools) at its

UK plant that would need to be re-machined. The time period to convert all of these tools would be ~ 1 year

at an estimated cost of € 1.2 million. Furthermore a major consideration is the reengineering of processes in

order to accommodate the alternative even if it were technically feasible. This would need to include

consideration of solvent recycling and emission capture since the volatility of the substance is quite different

from TRI.

HFE-72DE is not a “drop-in” solvent replacement for TRI as noted above. It would mean the replacing large

parts (if not completely) the existing production process and equipment. As per the ECHA SEA guidance,

the lost (book) value of existing equipment is considered a ‘sunk cost’ and therefore not considered in the

analysis. The additional capital and operating costs of making PE SLI battery separators is however relevant

to the assessment of economic feasibility.






125




battery separators to the existing markets after the sunset date), it is clear that switching to HFE-72DE is not

economically feasible.








that HFE-72DE is not economically feasible.

5.6.5 Availability

The substance mixture is commercially available.

5.6.6 Conclusion on suitability and availability for HFE-72DE

As described in Section 4 the R&D process identified that HFE-72DE is a potential alternative for TRI.

While initial laboratory trials indicate possibilities , there are numerous technical and economic challenges

that need to be evaluated before a final decision can be made on the suitability of HFE-72DE in the ENTEK

separator manufacturing process.



From an engineering and operations standpoint, a significantly higher vapour pressure, limited data for

recovery from activated carbon and potential degradation of its chemical components in the presence of

steam are problematic. The substance had a much higher cost compared to TRI (x 40-50 ). From a hazard

point of view, there is very limited information on the substance, however. based on the available

information it seems likely that the substance will possess similar hazard properties to other solvents, since

effects to the CNS and some irritation potential have been observed. Extensive further testing would be

required to ensure that the use HFE-72DE would not pose a similar level of hazard and risk compared to the

continued use of TRI.

126

5.7 N-PROPYL BROMIDE

The substance n-propyl bromide is a brominated hydrocarbon. Vapours may form explosive mixtures with

air, and the vapours may travel to source of ignition and flash back. Its vapours are heavier than air, so they

will spread along ground and collect in low confined areas.

N-Propyl bromide is a substance of very high concern (SVHC) under REACH on the basis of its

reproductive toxicity and it is therefore listed on the Candidate List for substance that can be recommended

for placing on Annex XIV.


Chemical Name(s): n-propyl bromide

Other names: 1-bromopropane, 1-propyl bromide, n-bromopropane



Molecular Formula: C3H7Br

Molecular Weight: 123


The harmonised classifications according to the CLP regulation no. 1272/2008 and to the Dangerous

Substances Directive 67/548/EEC are presented in the tables below.

Classification

area


1272/2008 Annex VI

Dangerous Substance Directive –according to

Directive 67/548/EEC


Health Skin Irrit. 2 Repr. Cat. 3; R62

Eye Irrit. 2 Repr. Cat. 2; R60

STOT SE 3 (H335) Xn; R48/20

STOT SE 3 (H336) Xi; R36/37/38

Repr. 1B R67

STOT RE 2 (H373)


Hazard H225: Highly flammable liquid and R11: Highly flammable

127

Classification

area


1272/2008 Annex VI



Statements vapour

H315: Causes skin irritation R60: May impair fertility

H319: Causes serious eye irritation R36/37/38: Irritating to eyes, respiratory system

and skin

H335: May cause respiratory

irritation

R62: Possible risk of impaired fertility

H336: May cause drowsiness or

dizziness

R67: Vapours may cause drowsiness and

dizziness

H360FD: May damage fertility. May

damage the unborn child

R48/20: Harmful: Danger of serious damage to

health by prolonged exposure through inhalation

H373: May cause damage to organs

through prolonged or repeated

exposure

R63: Possible risk of harm to the unborn child

The physico-chemical properties of n-propyl bromide are set out in table 5.19, below.

Table 5.19 Physico-Chemical Properties of n-propyl bromide

Properties



Flammability highly flammable vapours HSDB 2009

Vapour pressure 14.8 kPa at 20 ˚C ECHA 2013

Boiling point 71 ˚C ECHA 2013

Melting point -110 ˚C ECHA 2013

Water solubility 2450 mg/L at 20 ˚C HSDB 2009

Log Kow 2.16 ECHA 2013


From the research described in Section 3.2 of this document, it appears that n-propyl bromide may be a

technically feasible alternative to TRI as a process solvent for the manufacture of polyethylene battery

separators. While n-propyl bromide exhibits nearly the same oil extraction rate as TRI, its low flashpoint,

higher water solubility, and potential degradation in a high temperature steam environment are of concern.

However, the substance is disregarded as an alternative on the basis of risk, since it is an SVHC, flammable

and decomposition could lead to the formation of hydrogen bromide.

128

Furthermore, the extraction step is an integral part of the continuous process that ENTEK uses to

manufacture battery separators. The potential consequence of a fire or explosion with over 34,000 litres of

n-propyl bromide being circulated in a closed loop process at the UK plant would be catastrophic. The

arguments set out for n-hexane in terms of the capital and operational costs of converting a separator plant

for use of a highly flammable substance apply here also (see section 5.2.4).



129

Table 5.20 Hazard profile of n-propyl Bromide



Acute toxicity n-Propyl bromide is of low acute toxicity to animals (LD50 values in excess of >2500

mg/kg bw or LC50 35 000 mg/m3 air). The target organ is said to be the lungs.

ECHA 2013

Acute exposure to anesthetic levels on n-propyl bromide may result in lung and liver

injury.

HSDB 2009

Overexposure has resulted in effects to the Central Nervous System (CNS) resulting

in confusion, dysarthria, dizziness, paresthesias, and ataxia; unusual fatigue and

headaches, development of arthralgias, visual disturbances (difficulty focusing),

paresthesias, and muscular twitching. Symptoms may persist over one year after

exposure.

CDC, 2008

Skin or eye corrosion/irritation The substance is irritating to the eyes and the respiratory tract. ECHA 2013

Respiratory or skin

sensitization

Not sensitising ECHA, 2013

Carcinogenicity In animal studies n-propyl bromide caused tumours in the intestine, skin and lungs of

rats and mice.

NTP, 2013

Long term toxicity n-Propyl bromide is described as a neurotoxic and hepatoxic agent.

Exposure to 400 ppm n-propyl bromide for 28 days caused histopathological lesions

to the CNS. A NOAEL of 200 ppm based on no effects on the liver has been reported

for rats exposed to n-propyl bromide for 13 weeks.

HSDB 2009

Mutagenicity n-Propyl nromide has shown mutagenic activity in a mouse lymphoma assay.

However it is not mutagenic in vivo.

There is limited evidence that n-propyl bromide causes DNA damage in vivo.

ECHA 2013

NTP 2013

130


Endocrine disruption No information

Reproductive/developmental Rats exposed to n-propyl bromide showed effects in viability, sexual maturation and

body weight of offspring when exposed to doses above 100 ppm. Maternal toxicity

and feotoxicity was also observed in another study with rats exposed to doses in

excess of 100 ppm. The substance is classified as a reprotoxic substance (CLP

classification Repro 1B).

ECHA, 2013

Neurotoxicity n-Propyl bromide is a neurotoxic agent and acts by damaging the nerves in the arms,

legs, and body, and there is evidence suggesting this brain damage may also occur

after exposure to n-propyl bromide.

Cal/OSHA (undated)

HSDB 2009

Immune system toxicity Rats exposed to n-propyl bromide have experienced immunological effects. NTP 2013

Systemic toxicity No information

Toxic metabolites n-Propyl bromide may produce propylene oxide upon metabolisation. NTP 2013


Acute/chronic aquatic toxicity n-Propyl bromide is of low acute toxicity to aquatic organisms, LC50 and EC50

values have been reported in the range 72 to 203 mg/L.

An algal NOEC of 12.4 mg/L is available.

ECHA 2013

Bioaccumulation n-Propyl bromide is considered to have a low bioaccumulation potential and does not

fulfil the B in the PBT criteria.

The BCF has been calculated to be 11.29 L/Kg wwt (Log BCF 1.05). Owing to this

and its low log Kow.

ECHA 2013

Persistence n-Propyl bromide is not readily biodegradable. ECHA 2013


potential

n-Propyl bromide does not form greenhouses gases upon degradation.

Ozone-depletion potential The substance has been proposed as a replacement for ozone depleting solvents and it

is not classified as ozone depleting substance.

HSDB 2009 and Regulation (EC) No

2037/2000

131

n-Propyl bromide is considered a highly toxic substance due to its long lasting effects to the CNS following

repeated exposure and its reproductive toxicity. It is classified as a skin and eye irritant category 2, STOT SE

3, with the associated hazard phrase H335 (may cause respiratory irritation), STOT SE 3 with the associated

hazard phrase H336 (may cause drowsiness or dizziness) and STOT RE 2, with the associated hazard phrase

H373 (may cause damage to organs through prolonged or repeated exposure) and as a reproductive toxicant

category 1B under CLP. In addition, rats and mice exposed to n-propyl bromide have developed tumours in

the intestine, skin and lungs.

In short-term aquatic toxicity data the substance is not very toxic (with the lowest EC/LC50 being 72 mg/L).

Overall the hazard properties of n-propyl bromide do not make it a potential candidate for the substitution of

TRI.

PBT and CMR

n-Propyl bromide has been placed on ECHA’s candidate list as a substance of very high concern because of

its classification as reproductive toxin.

n-Propyl bromide does not fulfil the B criteria in the PBT assessment (see Table 5.8), therefore it is not

considered to be a candidate PBT or vPvB substance.


n-Propyl bromide is not a “drop-in” solvent replacement for TRI as noted above. It would mean the













battery separators to the existing markets after the sunset date), it is clear that switching to n-Propyl bromide

is not economically feasible.

132





be similar compared to using TRI. Optimistically factoring in that it would only takes a further 5 years for

ENTEK to recover their market share (i.e. 80% of lost profit in 2024, declining linearly to 0% in 2031) then

the net cost to ENTEK is €125 million (NPV). This further reinforces the conclusion that n-Propyl bromide

is not economically feasible.

5.7.5 Availability

The substance has been registered under REACH phase I at 1 000 to 10 000 tonnes per annum level.

Therefore it is considered to be sufficiently available.

5.7.6 Conclusion on suitability and availability for n-propyl bromide

The substance is classified as a reproductive toxin and is a CMR. As a result of this it is being considered as

an SVHC substance. In addition it may cause damage to the Central Nervous System.

On the basis of the substance leading to equal or greater risk it is not considered to be a possible alternative.



133

5.8 D-LIMONENE

Limonene is a naturally occurring terpene, found in citrus and other plants. It exists in two isomeric forms:

D- and L-limonene, and the racemic mixture diptene. The available data does not always distinguish between

two forms, in which case the substance is referred to as limonene. Commercial D-limonene generally has a

purity of 90-98%.


Chemical Name(s): 1-methyl-4-(1-methylethenyl)-cyclohexene

Other names: 4-isopropenyl-1-methylcyclohexene, p-menth-1,8-diene, Racemic: DL-limonene; Dipentene

Trade Name(s): not available



Molecular Formula: C10H16


134




Classification

area

CLP - according to Regulation

No 1272/2008 Annex VI



Physicochemical Flam. Liq. 3 R10

Health Skin Irrit. 2 Xi; R38

Skin Sens. 1 R43

Environmental Aquatic Acute 1 N; R50-53

Aquatic Chronic 1

Hazard

Statements

H315: Causes skin irritation R10: Flammable

H226: Flammable liquid and

vapour

R38: Irritating to skin

H317: May cause an allergic

skin reaction

R43: May cause sensitization by skin contact

H400: Very toxic to aquatic life R50/53: Very toxic to aquatic organisms, may cause

long-term adverse effects in the aquatic environment.

H410: Very toxic to aquatic life

with long lasting effects

Table 5.21 Physico-Chemical Properties of D-limonene

Properties



Flammability Flammable HBSD 200610

Vapour pressure 200 Pa at 16°C ECHA 2013

Boiling point 175-178°C ECHA 2013

Melting point -75°C ECHA 2013

Water solubility 13.8 mg/l at 25°C ECHA 2013

Log Kow 4.4 at 37°C ECHA 201311

10

HSDB 2006 for d-limonene, CAS 5989-27-5, accessed November 2013



http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~psqFjV:1

135

D-Limonene is a slightly yellow liquid at room temperature, classified as a flammable liquid (Fla. Liq. 3

according to CLP and R10 according to DSD). The substance has a boiling point of 175-178°C and a melting

point of -75°C. It has a water solubility of 14 mg/1, a vapour pressure of 200 Pa at 16°C and a log Kow of 4.4

at 37°C.

D-Limonene has a flashpoint of 51°C above which explosive vapour/air mixtures may be formed (HSDB

2006). It is said to react violently with a mixture of iodine pentafluoride and tetrafluoroethylene, causing fire

and becoming an explosion hazard, and it may also react with oxidants. [ECHA 2013 and HSDB 2006].

D-Limonene is not an oxidising agent and is stable at ambient temperatures


From the research described in Section 3.2 of this document, it appears that D-limonene may be a technically

feasible alternative to TRI as a process solvent for the manufacture of polyethylene battery separators.

Although it exhibits a slower extraction rate compared to TRI, this property could potentially be adjusted

with temperature of the extraction bath. While the low solubility of D-limonene in water is potentially

advantageous, its high boiling point and high heat of vaporization would add significant costs to the solvent

recovery process. Further research is required to understand if D-limonene could be used at a commercial

scale, and whether it would be compatible with all manufacturing and recovery processes such that the

resultant separator meets all customer requirements.



11

ECHA disseminated dossier on d-limonene, CAS 5989-27-5, accessed November 2013

http://apps.echa.europa.eu/registered/data/dossiers/DISS-9eb16d5d-b83e-2831-e044-00144f67d031/DISS-9eb16d5d-b83e-2831-e044-00144f67d031_DISS-9eb16d5d-b83e-2831-e044-00144f67d031.html

136

Table 5.22 hazard profile of D-limonene



Acute toxicity D-Limonene is not acutely toxic to animals, the oral and dermal LD50s are in excess

of 2000 mg/kg

ECHA 2013

Skin or eye corrosion/irritation Limonene is a skin irritant in humans and in experimental animals.

In rabbits, D-limonene was found to be an eye irritant.

WHO 1998

HSDB 2006

Respiratory or skin

sensitization

The substance itself is not a sensitizer, but air oxidized D-limonene induced contact

allergy in guinea pigs.

HSDB 2006

Carcinogenicity D-Limonene increases the incidence of renal tubular tumours in male rats, but the

mechanism of tumour formation in rats is not relevant to humans.

IARC 1999

Long term toxicity D-Limonene is a nephrotoxic agent in rats. The critical organ in animals (except for

male rats) following peroral or interperitoneal administration is the liver. There are

insufficient data to determine the critical organ in humans.

HSDB 2006

Exposure to limonene affects the amount and activity of liver enzymes and liver

weight.

WHO 1998

Reproductive/developmental Oral exposure to high levels of D-limonene has resulted in delayed maternal growth

and skeletal abnormalities have been observed in foetuses of laboratory animals.

IARC 1999

WHO 1998

Mutagenicity D-Limonene is not genotoxic in vitro and in vivo studies. HSDB 2006

Endocrine disruption No data

Neurotoxicity Decreased motor activity has been observed in mice administered D-limonene,

however it was difficult to ascertain whether this was due to direct effects of the

chemical or general intoxication.

HSDB 2006

WHO 1998

Immune system toxicity Some immune responses such as suppressed primary and secondary anti-keyhole

limpet hemocyanin and increased antibody and mitogen-induced proliferative

responses have been observed in a study with mice. However the purity of D-

HSDB 2006

WHO 1998

137


limonene was not established and it is possible that the effects seen were a response to

the oxidation products rather than the substance itself.

Toxic metabolites Toxic metabolites are not formed during the metabolisation of D-limonene. HSDB 2006


Acute/chronic aquatic toxicity Short-term toxicity effects have been reported with fish and invertebrates below

1 mg/L (LC50 and EC50 values of 0.38 and 0.72 mg/l respectively).

A long-term toxicity study with invertebrates from a surrogate substance indicates a

21 d NOEC with Daphnia below 1 mg/l (0.27 mg/l).

ECHA 2013

Terrestrial toxicity D-Limonene is used as an insecticide HSDB 2006

Bioaccumulation The calculated BCF is 360.5 to 1022 L/kg wet/wet (BCFBAF and OASIS

respectively).

The estimated BCF of 660 suggests that bioaccumulation potential is high.

ECHA 2013

HSDB 2006

Persistence D-Limonene is readily biodegradable (biodegradation in activated sludge is > 60%

ThOD).

Vapor-phase limonene is rapidly degraded in the atmosphere by reaction with

photochemically-produced hydroxyl radicals, nitrate radicals and ozone.

ECHA 2013

HSDB 2006


potential

The degradation of the substance does not produce greenhouse gases.

Ozone-depletion potential The oxidation of D-limonene can lead to the formation of hydrogen peroxide and

organic peroxides, however it is not indicated as an ozone depleting substance in

Regulation (EC) No 2037/2000, probably due to its rapid degrading in the

atmosphere.

WHO 1998 and

Regulation (EC) No 2037/2000.

138

D-Limonene, a terpene, is increasingly being used a solvent and is also used in food manufacturing and some

medicines. Therefore even though the substance is classified as a skin irritant category 2 and as a skin

sensitiser, the hazard properties of the substance to humans are considered sufficiently low to allow some

level of exposure to it.

D-Limonene is highly toxic to aquatic organisms in short- and long-term studies, and it is classified under

CLP as such: Aquatic Acute and Chronic category 1. D-Limonene is an active ingredient in biocidal

products, it is used as a repellent and as an insecticide. Therefore releases to the environment would need to

be monitored.

PBT and CMR

D-Limonene does not fulfil the PBT criteria, because it does not fulfil the P criteria based on rapid

biodegradation.

The substance is not considered as a CMR agent as it is not classified as a carcinogen, mutagenic or

reproductive agent.


The substance is disregarded on the basis of its flammability and in addition due to its heat of vaporization -

the energy costs required compared to TRI would be ~ 50% higher. D-Limonene is not a “drop-in” solvent

replacement for TRI as noted above. It would mean the replacing large parts (if not completely) the existing

production process and equipment. As per the ECHA SEA guidance, the lost (book) value of existing

equipment is considered a ‘sunk cost’ and therefore not considered in the analysis. The additional capital

and operating costs of making PE SLI battery separators is however relevant to the assessment of economic

feasibility.





comparing the minimum cost of lost profit for 12 years of €116 million NPV (see SEA section 4.2.1 for

details on lost profits, but using a discount rate of 7% rather than 4% in the SEA) with the cost of building

additional production lines at the existing US site (in Oregon) which is €48 million (see Section 4.2.2 of the

SEA); which enables ENTEK to avoid any production/sales disruption (i.e. can provide battery separators to

the existing markets after the sunset date), it is clear that switching to D-Limonene is not economically

feasible.

139








that D-limonene is not economically feasible.

5.8.5 Availability

The substance has been registered under REACH at a 10,000 to 100,000 tonnes per annum band, therefore it

can be considered to be readily available.

5.8.6 Conclusion on suitability and availability for D-limonene

As described in Section 3 the R&D process identified that D-limonene could be a potential alternative for

TRI. While initial laboratory scale evaluation shows promise, D-limonene is eliminated as a possible

alternative to TRI because it is flammable and based on its heat of vaporization the energy costs required

compared to TRI would be ~ 50% higher.



140

5.9 ACETONE

Acetone is an organic compound naturally found in the body. It occurs as a metabolic by-product of animals

and plants and is emitted by volcanoes and during forest fires. Its main use is as a solvent to dissolve paints,

varnishes, oils, resins etc.


Chemical Name(s): acetone, 2-propanone

Other names: propan-2-one, dimethyl ketone, dimethyl formaldehyde, dimethylketal, β-ketopropane, ketone

propane, ketone methyl, propanone, 2-propanone, pyroacetic acid, pyroacetic ether, pyroacetic spirit

(archaic)

CAS Number: 67-64-1


Molecular Formula: C3H6O





Classification

area

CLP - according to Regulation

No 1272/2008 Annex VI




Health Eye Irrit. 2 Xi; R36

STOT SE 3

Affected organs: narcotic effect


R66

R67

Environmental No classification No classification

Hazard

Statements

H225: Highly flammable liquid and

vapour

11: Highly flammable

141

H319: Causes serious eye irritation 36: Irritating to eyes

H336: May cause drowsiness or

dizziness

66: Repeated exposure may cause skin dryness or

cracking

EUH066: Repeated exposure may

cause skin dryness or cracking.

67: Vapours may cause drowsiness and dizziness

Table 5.23 Physico-Chemical Properties of Acetone

Properties



Flammability Highly flammable (flash point below 20˚C) ECHA 2013

Vapour pressure 24.3 kPa at 20˚C OECD 1999

Boiling point 56.1˚C ECHA 2013

Melting point -94.8˚C ECHA 2013

Water solubility Soluble ECHA 2013

Log Kow -0.24 OECD 1999

Acetone is a colourless liquid at room temperature with a mildly pungent and somewhat aromatic odour.

Acetone is flammable, owing to its low flash point (below 20˚C). The vapour/air mixtures are explosive and

heating will cause a rise in pressure with the risk of bursting.


As discussed in Section 4.2.1, acetone is a poor solvent and not fully miscible with naphthenic process oils.

While other ketones such a methyl ethyl ketone (MEK) and methyl iso-butyl ketone (MIBK) would be

expected to have a higher degree of solvency for the process oil, all of these compounds have high

flammability. As such, acetone and other ketones are not viable in the ENTEK separator manufacturing

process. As for n-hexane this leads to considerable difficulties and costs which are set out in section 5.2.4.


Acetone is generally of low toxicity, however it is subject to a SCOEL recommendation for an occupational

exposure limit for the protection of workers at EU level12. The iOEL is summarised as follows:


142

STEL (15 min): 1000 ppm [2420 mg/m3]

Notation: none

The UK’s Health and Safety Executive (HSE) has issued a long term work exposure limit (WEL) of (8h)

500 ppm (1210 mg/m3), and a short term WEL of (15min) 1500 ppm (3620 mg/m

3).


12 Recommendation from the Scientific Committee on Occupational Exposure Limits on Acetone

SEG/SUM/74, March 1997

143

Table 5.24 Hazard profile of Acetone



Acute Toxicity

Acute toxicity Very low acute toxicity via oral, dermal and inhalation exposure (LD/LC50 values are >5000

mg/kg bw and 50 000 mg/m3) in experimental animals.

ECHA 2013

Exposure at high levels could cause lowering of consciousness. ICSC 2009

Skin or eye corrosion/irritation Acetone has been shown to be an eye irritant in animal studies. ECHA 2013

Respiratory or skin

sensitization

In animal studies, acetone has been found not to be a sensitising agent. ECHA 2013 and OECD 1999

Chronic Toxicity

Long term toxicity The NOELs in the drinking water study were 1% for male rats (900 mg/kg/d) and male mice

(2258 mg/kg/d), 2% for female mice (5945 mg/kg/d), and 5% for female rats (3100 mg/kg/d).

The main findings were reduction in spleen weight and an increase in liver weight in mice.

OECD 1999

Reproductive/developmental Acetone has shown to be of low reproductive and developmental toxicity when exposed by

inhalation or via the drinking water.

The NOEL for developmental toxicity was 5220 mg/m3 for both rats and mice. The NOEL

for teratogenic effects were in rats and mice was ≥26,110 and ≥15,665 mg/m3, respectively.

OECD 1999

In mice a NOAEL of 2200 ppm has been determined for developmental toxicity based on

reduction in foetal weight and an increase in late resorption.

NTP 1988

Carcinogenicity There are no studies available on the carcinogenicity of acetone , however acetone has been

used as a solvent vehicle in skin carcinogenicity studies.

Topical treatment of mice with 0.1 and 0.2 ml acetone once or twice per week did not induce

an incidence of tumours above the background levels.

EHC 1998

OECD 1999

Mutagenicity Acetone has been generally proven to be non-mutagenic

ECHA 2013 SUM 1997

Neurotoxicity Acute exposure to acetone has been found to alter performance in neurobehavioural tests in EHC 1998

144


laboratory animals at concentrations greater than 7765 mg/m3 (>3270 ppm).

Acute exposures to acetone have been reported to alter performance in neurobehavioural tests

in humans at 595 mg/m3 (250 ppm).

Immune system toxicity The T cells response capacity was measured respond in mice treated with up to 1144 mg/kg

bw and was found to be unaltered.

EHC 1998

Systemic toxicity Acetone is moderately toxic to the liver and has some haematological effects. The mechanism

of these effects is unknown. The renal toxicity may be due to the formation of known

nephrotoxic agent, formate, which is excreted by the kidneys (Hallier et al., 1981).

EHC 1998

Toxic metabolites None EHC 1998


Acute/chronic aquatic toxicity Acetone is virtually non-toxic in short-term and long-term aquatic toxicity tests (EC/LC50

values in the range 2100 to 15000 mg/L and NOECs >1000 mg/L).

OECD 1999

Terrestrial toxicity Acetone is of low toxicity to terrestrial organisms with NOECs of >80 mg/L in plants and

>40 000 mg/kg in avian toxicity studies.

OECD 1999

Bioaccumulation Bioaccumulation is not of concern for this substance due to its low log Kow (calculated BCF =

3) and low persistence in the environment.

ECHA 2013

Persistence Acetone is considered as readily biodegradable (ca. 90% biodegradation after 28, 10-d

window criteria fulfilled)

ECHA 2013


potential

None found

Ozone-depletion potential Acetone is not indicated as an ozone depleting substance in Regulation (EC) No 2037/2000. Regulation (EC) No 2037/2000

Acetone degrades in the atmosphere by reacting with OH* radicals. The reactions with ozone

(OD) or NOx are considered to be too slow to be important under tropospheric conditions.

EHC 1998

Acetone does not have a high toxicity profile. Exposure to high levels of acetone can cause

depression of the Central Nervous System (CNS) and it is classified as such under CLP

(STOT SE3). It is also an eye irritant in animals. No other significant hazards have been

found for human health and the environment.

PBT/CMR and any other regulatory actions

Acetone does not fulfil any of the criteria for PBT and is not classified as a CMR agent. No

regulatory action is currently being taken with this substance.


The substance is disregarded on the basis of not being technically feasible. Acetone is not a

“drop-in” solvent replacement for TRI as noted above. It would mean the replacing large

parts (if not completely) the existing production process and equipment. As per the ECHA

SEA guidance, the lost (book) value of existing equipment is considered a ‘sunk cost’ and

therefore not considered in the analysis. The additional capital and operating costs of making

PE SLI battery separators is however relevant to the assessment of economic feasibility.

A major consideration is the reengineering of processes in order to accommodate the

alternative even if it were technically feasible. This would need to include consideration of

solvent recycling and emission capture. This has not been estimated given the significant

technical (feasibility) difficulties. As set out in Section 6.2, it would take a minimum of 12

years to make a possible alternative solvent suitable. When comparing the minimum cost of

lost profit for 12 years of €116 million NPV (see SEA section 4.2.1 for details on lost profits,

but using a discount rate of 7% rather than 4% in the SEA) with the cost of building

additional production lines at the existing US site (in Oregon) which is €48 million (see

Section 4.2.2 of the SEA); which enables ENTEK to avoid any production/sales disruption

(i.e. can provide battery separators to the existing markets after the sunset date), it is clear that

switching to acetone is not economically feasible.

The €116 million is considered a minimum costs as it excludes any capital costs as well as

some additional costs like redundancy (over the period 2016-2027) and assumes post 2027,

ENTEK can make equivalent profits. This assumption is however highly unlikely since (i) it

assumes ENTEK would not have lost any market share due to no sales after the sunset date

(April 2016) to 2027, and (ii) assumes profit margins would be similar compared to using

TRI. Optimistically factoring in that it would only takes a further 5 years for ENTEK to

recover their market share (i.e. 80% of lost profit in 2024, declining linearly to 0% in 2031)

146

then the net cost to ENTEK is €125 million (NPV). This further reinforces the conclusion

that acetone is not economically feasible.

5.9.5 Availability

Acetone is widely used and available. In the EU it is distributed at 1*105 to 1*10

6 tonnes per

annum range.

5.9.6 Conclusion on suitability and availability for Acetone

Acetone is not a viable alternative because of its poor miscibility with the naphthenic process

oils. The potentially large expected capital cost to switch and loss in profits compared to the

costs of building additional production lines in the US, means this alternative is also not

economically feasible.

5.10 ASSESSMENT OF TECHNICAL ALTERNATIVES

This section is addresses the possible alternatives to PE battery separators, i.e. separators that

can be used in lead-acid batteries that are not produced with TRI. The focus of this analysis

of alternatives is on replacement of the function of TRI, that is finding a way of extracting oil

from PE separators without using TRI. However, since the analysis of alternatives should be

in-line with the non-use scenario the possible alternatives to PE separators are discussed here.

Some understanding of lead-acid batteries is set out first so that the possibilities of use for

other types of is clear, before considering the possible alternatives.

5.10.1 Lead Acid Battery Classifications

Lead acid batteries are often classified into the following categories based on their application

and use:

1. SLI (Starter, Lighting, and Ignition) --- used in automobiles

2. Start-Stop --- designed to operate in automobiles where internal combustion

engine shuts off during stops to reduce CO2 emissions;

3. Stationary --- used for back-up power supply for telecommunication, electric

utility, or computer systems.

4. Motive Power --- industrial batteries used to power forklifts, floor scrubbers,

etc.

5. Special Purpose --- military equipment, submarines, etc.

In terms of maintenance, lead acid batteries are classified as follows:

1. Flooded --- require water addition because grid alloys with high antimony (Sb)

content catalyze hydrogen and oxygen loss

2. Maintenance Free --- contain lead/tin/calcium grids for the positive plates and

lead/calcium grids for the negative plates

3. Valve Regulated (VRLA) --- utilize lead/tin/calcium grids and absorptive glass

mat (AGM) separators.

As mentioned in the SEA report, lead-acid polyethylene separator starting lighting and

ignition (PE SLI) batteries compete to some extent with absorbed glass mat (AGM) separators

that are used within valve regulated lead acid (VRLA) batteries. As vehicles become more

advanced, including more electrical devices and features, the demands of the battery

supplying the power to these devices are increasing. These new electronic and technological

advancements need batteries to power them along with greater cycling (charging and

discharging) capabilities. VRLA batteries are marketed as providing this enhanced power

source for electronic features. The advancement of the VRLA market could lead to erosion of

PE SLI lead acid batteries’ market share. As mentioned in Section 3, the applicant does not

participate in this alternative separator technology and has determined that this is not a market

in which they can compete successfully.

5.10.2 Alternative separator products

Currently, there is a separator available in the marketplace for lead acid batteries that ENTEK

does not manufacture. Absorptive glass mat (AGM) separators are used in Valve Regulated

Lead Acid (VRLA) batteries. These separators have extremely high porosity (>90%) and are

composed of interconnected micron-sized glass fibres as shown in Figure 5.13.

148

Figure 5.13 Scanning electron micrograph of an AGM separator.

As mentioned in the SEA report, lead-acid polyethylene separator starting lighting and

ignition (PE SLI) batteries compete to some extent with absorbed glass mat (AGM) separators

that are used within valve regulated lead acid (VRLA) batteries.

As shown in Figure 5.14 , an AGM separator is white and has smooth parallel faces, whereas

polyethylene separators are grey with ribs of different heights across the face of one side.

Table 5.25 shows some key separator characteristics and the distinct differences between

these two types of separators. It is clear from these differences that one separator type cannot

simply be substituted for the other in the same battery design.

Figure 5.14 Photograph shows AGM separator and polyethylene separator made by

ENTEK

One advantage of the AGM separator is that it can immobilize the required amount of

sulphuric acid between the positive and negative electrodes, such that a lead acid battery can

operate in different orientations without the risk of an acid spill. A disadvantage of the AGM

separator is its weak mechanical properties result in a lower production rate for VRLA

batteries. In general, VRLA batteries are approximately 2.5-3 times more expensive than

conventional flooded SLI batteries. Table 5.25 shows a comparison of key separator

characteristics for the two most common separators used in lead acid batteries.

Table 5.25 Key separator characteristics for the two most common separators

used in lead acid batteries

Attribute Polyethylene Separator Absorptive Glass Mat

Backweb Thickness (mm) 0.15-0.25 1.5

Overall Thickness (mm) 0.6-1.9 1.5

Porosity (%) 55-60 93

Puncture Strength (N) 5-10 1

Electrical Resistance (mΩ-

cm²) 80-105 40

VRLA batteries are widely used in large portable electrical devices, off-grid power systems

and similar roles, where large amounts of storage are needed at a lower cost than other low-

maintenance technologies such as lithium-ion. VRLA batteries are also used in ‘start-stop’

vehicle applications because of their excellent cycle life and low susceptibility to acid

stratification. The higher cost of VRLA batteries limits their adoption to only luxury

vehicles, whereas an Extended Flooded Battery (EFB) design which uses a polyethylene

separator is used in more modest vehicles with fewer electrical loads. There exists a growing

market for EFB for new vehicles, but also a significant market for battery replacement in

existing automobiles (the so-called ‘car park’). Although, it might be possible in some cases,

for a VLRA battery to be used for battery replacement, the much greater cost without the

added benefit would not be justified. In addition it is known that VRLA batteries are limited

to specific sizes (indicated by DIN number specification), so that the selection of a VRLA for

replacement would be limited. A more comprehensive analysis of the market for battery

types and the after sales (battery replacement) market for EFB in the European car park is

presented in the SEA.

150

6 OVERALL CONCLUSIONS ON SUITABILITYAND AVAILABILITY

OF POSSIBLE ALTERNATIVES FOR USE OF

TRICHLOROETHYLENE AS AN EXTRACTION SOLVENT FOR

REMOVAL OF PROCESS OIL AND FORMATION OF THE POROUS

STRUCTURE IN POLYETHYLENE BASED SEPARATORS USED IN

LEAD-ACID BATTERIES

6.1 OVERALL CONCLUSION

The conclusion of this analysis of alternatives is that there are no alternatives that are suitable

and available to the applicant for the replacement of the Annex XIV substance function. A

number of possible solvent alternatives have been tested at laboratory scale by ENTEK.

Although it was found that for one or two of the alternatives (see Table 6.1 below) there was

some potential for the replacement of TRI, a considerable amount of further research would

be required to determine the technical feasibility of these substances at a commercial scale.

In addition, the customer acceptability of the products manufactured using an alternative

would also have to be ensured.

Confidential

Table 6.1 below presents a summary of the solvents that were researched for their potential to

replace TRI in the ENTEK process. Each substance is evaluated against the criteria of

technical feasibility, economic feasibility, risk and availability. It should be noted that:

1. The assessment of economic feasibility can be complex and is not simply a case of

comparison of the cost of the possible alternative with the Annex XIV substance.

2. In some cases where the possible alternative has already be shown as not technically

feasible or will lead to equal or greater risk than the Annex XIV substance, there is

little point in the assessment of economic feasibility, because that becomes irrelevant.

Table 6.1 Summary of findings of the analysis of alternatives for substances

Substance Technical feasibility Economic feasibility Similar or additional risk? Availability

n-hexane Possible on basis of lab trials.

Presents difficulties due to high

volatility and very high flammability.

Is not possible to use for a continuous

process.

No - The large expected capital cost to

switch and loss in profits compared to the

costs of building additional production

lines in the US, means this alternative is

also not economically feasible.

Highly flammable. Neurotoxin and

reproductive toxin.

Likely to come under further regulatory

pressure in future.

Presents control difficulties due to high

volatility.

Yes

Dichloro-

methane

(methylene

chloride)


Not technically feasible without

considerable further research and

commercial testing for customer

acceptability of the product.






Suspect Carcinogen.


pressure in future.

Yes

Tetrachloro-

ethylene

(perchloroet

heylene)











Suspect Carcinogen.


pressure in future.

Yes

Vertrel®

SDG












No. However, little data available. Yes

HFE 72DE

1,2-







No. However, little data available.. Yes

152






n-propyl

bromide (1-

bromopropa

ne)











SVHC (repro. toxin). Flammable Yes

D-Limonene Possible on basis of lab trials.

Likely to be problems with solvent

recovery and recycling.






Flammable.

Dangerous to the environment.

Yes

Acetone No – does not perform function to

remove process oil effectively.






No Yes

As addressed in this Section, consideration of an alternative solvent should take into account

the risks of using the substance in the specific process. A key consideration that is closely

associated with this is the regulatory status and pressures on a potential alternative (since

these are related to hazard and risk). The introduction of a potential alternative into a process

requires considerable time and money to test the technical feasibility at a commercial scale

and to ensure consumer approval of the final product. It would therefore be a considerable

business risk for a firm to invest in process-change that would have a very limited life-span.

In the case of some solvents, notably n-hexane, this could mean not only rebuilding of a

facility but relocation of a plant all of which would come at considerable cost which is judged

to make the possibility to convert to the use of n-hexane not economically feasible.

As indicated in Section 4, solvent substances that showed some promise in ‘bench-scale’

trials are also under some regulatory scrutiny in the EU and elsewhere. Although not perhaps

meeting the current specific criteria for SVHC and therefore not potentially subject to the

need for authorization today, this may change in the future, this could easily be the case for n-

hexane which is a neurotoxin and a reproductive toxin. Indeed, recent years have seen TRI

change from classification as a Cat. 2 carcinogen to a Cat. 1B carcinogen today the status of

TRI as a non-threshold carcinogen has been adopted by ECHA for the purpose of assessing

authorisations applications. Tetrachloroethylene and methylene chloride are both currently

classified as carcinogens (Category 2, H351), and subject to evaluation under CoRAP (now

concluded) and restrictions, respectively. It is therefore unlikely to be sustainable in terms of

business planning to invest in substances with these risk profiles that (based on their

properties) would present similar challenges for emission/release control as TRI. The

implementation of a solvent alternative must therefore take account of possible regulatory

changes that would have a severe impact on the use of the substance in the future. It is clear

that for substance that showed the possibility for being alternatives to TRI in the ENTEK

process, n-hexane, tetrachloroethylene and methylene chloride that the regulatory and risk

profile of these substance now and in the future would rule them out as sensible options. In

particular for n-hexane since it is a particular focus due to its known use for the process of

making PE separators the financial implications of converting the facility or relocating the

facility have been set out and it has been concluded that it would not be economically viable

for ENTEK to convert or rebuild or relocate its UK plant to use n-hexane.

154

6.2 ACTIONS AND TIMEFRAME FOR IDENTIFICATION AND

DEVELOPMENT OF A SUITABLE AND AVAILABLE ALTERNATIVE.

There are a number of technical barriers to the use of an alternative solvent in the ENTEK

continuous separator manufacturing process. Even with no alternative currently technically

feasible, we consider how an industrial-scale trial of a solvent could be implemented and

describe that in terms of actions and associated timescales. First ENTEK must analyse

interaction between the alternative solvent and its equipment and likely retrofit its equipment

to adapt the metallurgy to the specific solvent and develop any appropriate solvent recovery

systems. ENTEK must then gain customer approval of its process and resulting separator

products made with the alternative solvent. To gain such approval, ENTEK must make a

significant quantity of samples for its various customers to test in the production of batteries.

For the customer qualification of the process, the samples must be made on the production

equipment that will be used to manufacture separators on an ongoing commercial basis. To

avoid cross-contamination with TRI, these samples can only be run during a temporary plant

shutdown period using the existing plant infrastructure. Concurrently, ENTEK would

undertake the engineering study to design the converted plant and the trial results would feed

into that engineering work. A 78 week program is estimated for the time needed to get

feedback on each trial from customers. ENTEK would be required to conduct at least three

separate trials to gain broad customer approval. In order to continue to meet current customer

demand, plant shutdowns of a sufficient duration are only scheduled in the month of

December. The total elapsed time in this plan is estimated to be a minimum of nine years.

This estimated time frame would not be adequate if ENTEK received any negative feedback

from customers or if customers delay in their willingness to participate in the trials. It is

noted that no replacement solvent is currently technically feasible without trials and extensive

restructuring of the plant, and possible candidate replacement solvents each pose similar or

greater risks than TRI.

A plan, to indicate the main actions and timescales that would be required in order to

investigate the technical feasibility and commercial viability of two alternatives solvents, is

set out below.

Table 6.2 Solvent Conversion Plan ENTEK Newcastle Facility

Task

Estimated

Duration

(weeks)

1.Lab-scale Research & Development

Initial Candidates: Dichloromethane, Tetrachlorooethylene

Extraction Rate

Drying with Steam

Shrinkage

Physical Properties

Electrical Properties

Drying Without Steam

Shrinkage

Physical Properties


Establish Screening Plan for Additional Candidates

60

2.Pilot Scale Extraction and Drying

With Steam

Shrinkage

Physical Properties


Samples to Customers for Preliminary Evaluation

Without Steam

Shrinkage

Physical Properties


Samples to Customers for Preliminary Evaluation

Preliminary Estimate of Parameters Needed for Tooling Design

78

3.Engineering Analysis - Plant Trial 52

156

Identify all Physical and Thermodynamic Properties Required for Detailed

Design

Evaluate Available Data and Fill in Database

Estimate Properties, as needed

Identify all Current Unit Operations

Develop Mathematical Models for all Unit Operations

Estimate Model Accuracy

Identify Where Physical Testing is Needed

Develop Physical Testing Methods as Required

Identify Need for Upgraded/New Unit Operations

Preliminary Design of Upgraded/New Unit Operations

Preliminary Cost Estimate for Upgraded/New Unit Operations

Material Balance

Energy Balance

Production Scenario: Volumes and Yields

Economic Analysis of Alternatives

Implementation Plan for Conversion

4.Research and Development Confirmation of Engineering Design

Plant-Level Trial

Trial Plan

Design of Upgraded/New Unit Operations for Trial

Build/Procurement of Required Unit Operations and Equipment

Installation

Start-Up

Run Trials

20

Verify/Refine Tooling Design Parameters

5. 1st Roll Samples and Preliminary Qualification

Production Part Approval Process (PPAP) for Process and Products

Identify End-Users for PPAP Trials

Identify Starting-Lighting-and Ignition Profiles for PPAP

Identify Industrial Profiles for PPAP

Build Required Tooling

Build SLI Profiles

Build Industrial Profiles

Send Roll Samples and Process Capability Data to Customers

Obtain PPAP Qualification from Customers

Build Samples for Customers

4

Battery Trials: Bench and Field Testing 78

6. 2nd Roll Samples and Preliminary Qualification






Build SLI Profiles



8

158

Battery Trials: Bench and Field Testing 78

7.Final Roll Samples and Full Product/Process Qualification






Build SLI Profiles



Obtain PPAP Qualification from Customers

4

Build Samples for Customers

Battery Trials: Bench and Field Testing

SLI Product Approval from ENTEKs Customer's Customers

Industrial Product Approval from ENTEK's Customer's Customers

78

8.Engineering Analysis - Conversion

Identify all Physical and Thermodynamic Properties Required for Detailed

Design

Identify Need for Upgraded\New Unit Operations

Preliminary Design of Upgraded/New Unit Operations

Preliminary Cost Estimate for Upgraded/New Unit Operations

Material Balance

Energy Balance

Production Scenario: Volumes and Yields

Economic Analysis of Alternatives

13

Implementation Plan for Conversion

9.Conversion

Build/Procurement of Plant-Wide Required Unit Operations and Equipment

104

Installation 30

Start-Up 15

Qualification of Plant-Wide Process 15

Total Time 12.4 years

The conclusion from this table is that a minimum of 12 years would be required to convert to

a substitute solvent. (It should be noted that the table above sets out the best case scenario

and does not account for likely barriers such as regulatory compliance requirements such as

permitting, etc.)

Confidential

160

APPENDIXES AND ANNEXES

(Include other information that you consider relevant for the Analysis of Alternatives,

e.g., list of data sources, data collection approach, organisations consulted, summary

of assumptions, etc.)

ANNEX I – JUSTIFICATION FOR CONFIDENTIALITY CLAIMS

Blanked out item

reference Page

number Justification for blanking

Text below table

1.2 14/15/16 Confidential R&D

See justification text below.

4.2.1 Research

and Development 44 Confidential R&D


4.2.2

Manufacturing

Alternatives

57-66 Confidential R&D


6.1 second

paragraph

146 Confidential R&D


Text below table

6.2 182 Confidential R&D


Justification for Confidentiality

1. Demonstration of commercial interest

ENTEK is expending material resources on the development of separator

technologies and manufacturing processes. Each unique approach is not yet patent

protected.

The separator technologies and manufacturing processes for lead acid separators

that are being investigated are entirely unique and whilst in the very early stages

of development, ENTEK are confident that further research and development

efforts could provide ENTEK with a distinct competitive advantage.

2. Demonstration of potential harm

The exceptions referred to in Article 4 of regulation (EC) No 1049/2001 are

relied upon by ENTEK in justifying the confidential treatment of information.

Article 4 (2) specifically makes provision for ECHA to refuse access to

information or documents where disclosure 'would undermine the protection of

commercial interests of a natural or legal person, including intellectual property

unless there is an overriding public interest in disclosure'.3

The information that is subject to the request is highly confidential business

information relating to R&D activity that is not in the public domain. Disclosure

of the information would damage ENTEK’s prospects of obtaining patent or other

intellectual property protection for candidate processes in future by making it

publicly known. Additionally, ENTEK has certain pending patents and any

disclosure could result in a waiver of ENTEK’s intellectual property rights. This

in turn would adversely affect ENTEK's return on its investment in R&D in new

separator technologies and manufacturing processes.

Publication of the relevant information would also damage ENTEK's commercial

interests by disclosing its R&D strategy to the public, removing the potential

competitive advantage that it represents. It is probable that ENTEK's actual and

potential competitors would quickly gain access to this information through their

routine market intelligence activity. They are likely then to use this information to

'free-ride' on ENTEK's investment by replicating its activity, or to disrupt the

development of the new technology.

Furthermore, the information in question is highly confidential and relates to

ENTEK's future commercial strategy in the markets where it operates. It is

therefore precisely the type of information that EU and national competition laws

do not want companies disclosing to their actual or potential competitors, whether

directly or via a third party such as ECHA, because of the risk that competition

would be restricted or distorted as a result.

More generally, because of the commercial and legal risks summarised above,

ENTEK notes that any policy of publication by ECHA of non-public R&D

information would be likely to have a chilling effect on innovation and

competition in this sector over time. The incentives for applicants to invest in

developing alternatives to their authorised substances will be significantly reduced

going against one of the main objectives of REACH namely, to enhance

competitiveness within the market place4.

It is understood that in considering the justification for confidentiality the Agency

will weigh up the private commercial interests of ENTEK against the general

public interest in ensuring transparency of information, and the specific public

interest guaranteed by REACH in ensuring a high level of protection of human

3 Regulation (EC) No 1049/2001 Of The European Parliament And Of The Council of

30 May 2001 regarding public access to European Parliament, Council and

Commission documents.

4 Decision of the Chairman of the Board Of Appeal of the ECHA Joined cases A-011-

2013 to A015-2013;

162

health and the environment5. That being said it is essential that the agency take

into consideration the fact that there is no public or consumer exposure to any of

the separator technologies or manufacture processes that would justify an

'overriding public interest' in disclosure of ENTEK's R & D activity.

3. Limitation to validity of Claim

Research and development are very much in the early stages with further work to

be carried out around development, cost analysis and positive battery test results.

ENTEK therefore request for all information concerning ‘Research and

Development' to remain confidential until such time that the information is

disclosed by ENTEK itself or published or otherwise becomes part of the public

domain through no fault of ECHA but only after it becomes part of the public

domain.

5 Decision of the Chairman of the Board Of Appeal of the ECHA Joined cases A-011-

2013 to A015-2013.

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