respirable crystalline silica (rcs) hugus.pdf · respirable crystalline silica (rcs) understanding...

Respirable Crystalline Silica (RCS)Understanding the Regulations, Science & Results

Marc Hugus

Manager, Business Development

MTA-PALMS RCS – Understanding the Regulations, Science & Results 2

Marc Hugus – Manager, Business Development

Over 30 years consultative technical business development, sales and marketing experience in Oil and Gas, Engineering, Environmental Consulting and Automated Mapping and GIS

Bachelors and Masters degrees in Geography

Over 6 years experience in environmental and industrial hygiene laboratory sales and customer service

Knowledgeable in OSHA and EPA regulations for air, water, soil and industrial hygiene sampling and analysis

Involved with IPO’s for 4 companies, including MapQuest.com


What is Silica?

• Family of materials consisting of silicon dioxide (SiO2)

– Crystalline mineral and amorphous material

• Concern is Crystalline Form

– a solid 3D structure of SiO2 atoms having fixed distances, preferred orientation(s) and arrangement

– Quartz is the most ubiquitous compoundon earth (~43% by weight)

Regulated Crystalline Silica Polymorphs (Respirable)

Quartz TridymiteCristobalite


What is a Respirable Particle?• < 10 microns (aerodynamic mass diameter)

• Inhaled particles can reach deep regions of lung (Alveoli)

0

10

20

30

40

50

60

70

80

90

100

1 2 3 4 5 6 7 8 9 10 11

Aerodynamic Diameter (microns)

Fraction Collected (%)

2015 ACGIH TLVs and BEIs Appendix C


Exposure to Crystalline Silica

• Source material – Nature….rocks– Igneous – granite, other felsic igneous rocks

– Sedimentary – sandstone, shale, carbonates

– Metamorphic – schist, gneiss, quartzite, etc.

• How is it released?– Pulverized, crushed, fractured, etc.

• Potential risk for delayed health effects:– Silicosis

– Lung cancer

– Chronic obstructive pulmonary disease (COPD)

– Kidney disease


Work Activities of Concern

• Stone Cutting, Grinding and Polishing

• Foundry Operations

• Sand Blasting

• Manufacturing (e.g. Glass and Ceramics)

• Building Demolition/Renovation

• Concrete, Masonry and other Construction Materials

• Mining/Quarrying (various)

• Materials Handling/Packaging

• Bulk shipping/Transportation

• Agriculture

• Etc.


Assess, Recognize, Evaluate, Control & Confirm

• Review possible risks and exposures- Risk = Exposure (amount and duration) X Potential Toxicity

• Implement OEHS program(s)

• Evaluate containment capabilities- Conduct containment assessment

• Enhance containment systems- Work practices- Engineering controls

• Re-evaluate and confirm controls- Conduct exposure assessment


“New” OSHA Rules Summary

• Permissible Exposure Limit (PEL) reduced to 50 mg/M3 for 8 hour TWA

• Action Level (AL) reduced to 25 mg/M3 for 8 hour TWA

• Key Dates- Construction – September 23, 2017

- General Industry/Maritime – June 23, 2018- Hydraulic Fracturing* – June 23, 2018

*Engineering Controls – June 23, 2021

• On-going evaluation– If above AL but below PEL – Reevaluate exposure within 6 months

– If above PEL – Reevaluate exposure within 3 months- If below AL – Repeat monitoring within six months (2 samples at least 7 days apart) to confirm controls

– Changes in the production, process, control equipment, personnel, or work practices


OSHA Record Keeping

Exposure Monitoring – Air Sampling – Sample dates and tasks

– Sampling and analytical method used

– Number, duration and results for samples

– Laboratory identity

– PPE utilized during sampling

– Social Security Numbers for employees covered

Objective Data– Materials in question

– Comparable industry/task data sources

– Testing protocols/results

– Descriptions of processes and tasks

– Other relevant data


Various Sampling and Lab Methods(Crystalline Silica on Filters)

• MSHA – P7 (FTIR) – coal mines

• MSHA – P2 method (XRD) – metal/non metal mines

• NIOSH – 7500 (XRD)

• NIOSH – 7602 (IR-KBr pellet)

• NIOSH – 7603 (IR-redeposition)

• OSHA – ID 142 (XRD) – similar to NIOSH 7500


NIOSH 7500 Method Summary

• OSHA approved for analysis of silica in airborne dust

• Filter redisposition- Polyvinyl Chloride (PVC)

• Analysis by X-Ray Diffraction (XRD)


Polyvinyl Chloride (PVC) Filters

• Suitable for multiple NIOSH/OSHA/ASTM air sampling methods

• Silica

• Metals

• Dust (silica-free, low ash)

• Hydrophobic - low tare weight and moisture pickup for gravimetric stability

• Non-oxidizing surface

• Standard pore size 5mm for silica

Secondary electron image of

a PVC filter


Sample Collection

Sample Date Sample No. Sample Description MediaPump

No.

Pre-Flow

Rate

(L/min)

Start Time

Post-Flow

Rate

(L/min)

Stop TimeAvg. Flow

Rate

Total Time

(min)

Volume

(L)Analysis

Personal - Total Dust PVC (5.0) 0.0 0 0.0 NIOSH 0500

Personal - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500

Area 1 - Total Dust PVC (5.0) 0.0 0 0.0 NIOSH 0500

Area 1 - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500

Area 2 - Total Dust PVC (5.0) 0.0 0 0.0 NIOSH 0500

Area 2 - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500

PDR - Resp / Silica PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500

Field Blank PVC (5.0) 0.0 0 0.0 NIOSH 0500

Field Blank PVC (5.0) 0.0 0 0.0 NIOSH 0600/7500

Relinquished by: Date/Time

Method of Shipment: Hand delivered

Received by: Date/Time

Sample Condition Upon Receipt: Acceptable Other (explain on reverse)

XYZ Company Sample Collection Record

Chai

n o

f C

ust

ody

Page of

ATTENTION TO:Project No.: Client No.:

Date Logged In: Logged In By:

Name: Name: Email:

Company: Company: Fax:

Address: Address:

City, State, Zip: City, State, Zip:

Phone: Fax: Phone:

Call with verbal results:

Email results to:

Fax results to:

Accreditations required to be followed: yes no

Sample

Date

Relinquished By (Signature): Date: Time: Received By (Signature): Date: Time:

Relinquished By (Print Name): Received By (Print Name):

Company Name: Method of Shipment: Company Name: Method of Shipment:

Relinquished By (Signature): Date: Time: Received By (Signature): Date: Time:

Relinquished By (Print Name): Received By (Print Name):

Company Name: Method of Shipment: Company Name: Method of Shipment:

Sample

LocationSample Description

Quality System

Requirements

(if applicable)

Circle which ones

to follow:

Analysis Requested Special Instructions or Comments

ISO (Please specify):

cGMP:

Other (Please specify):

Client Sample ID

Relinquished To:

Relinquished To:

Chain of

Custody

Chain of

Custody

Chain of

Custody

Chain of

CustodyRelinquished To:

Send

Invoice

To

Relinquished To:

Date Results

Requested

Yes

Lab Use

OnlyClient Job Number:

Standard TA assumed if left blank;

please do not use vague terms like ASAP

Request for Laboratory Analytical Services - Chain of Custody

Rush Charges

Authorized ?

(circle one)

Purchase Order Number:

No

Report

Results

To


Size Selective Sampling – Cyclones

Cyclone

10-mm nylon cyclone

Higgins-Dewell (HD) cyclone

SKC Aluminum cyclone

BGI GK 2.69 cyclone

Flow Rate

1.7 L/min

2.2 L/min

2.5 L/min

4.2 L/min

• Ensure the cassette is loaded into the cyclone properly

• Do not invert sampler assembly while using the cyclone Air Inlet

Grit pot

Coarse

Respirable


Sampler Calibration

• Calibrate flow rate to primary standard

• Include entire sampling train

• Direct flow check (rotameter) or Bell Jar (“old school”)

• Check flow rate before and after sampling


SKC PPI Sampler

• Parallel Particle Impactor (PPI) from SKC, Inc.

• Alternative sampler- Eliminates need for cyclone (no inversion issues)- Compatible with multiple sampling pumps- Available in 2L, 4L and 8L- Increases worker comfort

• OSHA approved


Exposure Monitoring Tips

• Inspect and Test Equipment

– Cassettes for cracks/leaks

– Integrity of tubing

– O-rings and seals

– Clean cyclone and grit pot

• Orientation of Sample Inlet and Cyclone

• Maximize Sampling Air Volume

• Know Where your Sampler has Been

• Augment with Direct-reading Instruments

• Avoid Sampler Contact with Settled Dust

• Moderate Potential Interferences


NIOSH 7500 Laboratory Analysis

Follow a Sample throughthe Laboratory


X-Ray Diffraction (XRD)

• Used to Evaluate Crystalline Materials

• NIOSH 7500, Crystalline Silica by XRD

• Three regulated crystalline silica minerals

- Quartz, cristobalite, and tridymite- Other methods may not differentiate the 3 polymorphs


Cassette Assembly

• Filters Used (typical)– 5 µm pore size

– 37 mm diameter

– Polyvinyl chloride (PVC)

• Pre-weights– Weighed in sets of 10

– Every 10th weight is re-weighed to ensure that the balance did not drift during weighing of the set


Cassette Assembly (continued)

• Assemble Cassette– 2 or 3 piece depending on

cyclone

– SKC PPIs

• Tracking Number– Unique ID for each cassette

– Identifies pre-weight of filter and time/date of assembly


Sample Preparation (1)

• Samples received

• Dried in a desiccator

• Cassettes carefully opened to remove filters

• Filters post-weighed

• Total respirable dust mass calculated

‘Gravimetric Analysis’NIOSH 0500NIOSH 0600



• NIOSH 7500 Options

– Low temperature plasma ashing (beaker)

• 1 hour @ ~ 150°C

– Muffle furnace ashing(crucible)

• 2 hour @ 600°C

– Filter dissolution

• Tetrahydrofuran (THF)



• 15 mL of 2-Proponal is added to each beaker

• Cover and sonicate

• Obtain a silver membrane filter

– 25 mm

– 0.45 µm

• Attach funnel



• Pour suspension into the funnel

• Rinse walls of beaker

• Apply vacuum

• Remove the silver filter with the sample deposited on it



• Mount into XRD holder

• Place in orderly fashion

• Ready for analysis


X-Ray Diffractometer

PANalytical Cubix3 Diffractometer

X-raySource

Detector

Goniometer

Sample


XRD Basics

• Bombardment of X-rays results in scattering of the X-rays off of atomic planes

• X-Ray diffraction produces patterns that are indicative of the atomic planes in a material, which serve as a fingerprint for individual minerals

d

Incident X-ray beam

Diffracted beam

q

qAtomic Planes

λ

λ = 1.54 Å, CuKa

nλ=2dsinΘ


XRD Data

Position [°2Theta] (Copper (Cu))10 20 30

Counts

0

40000

160000

360000


XRD Data

QuartzSilverSilver Chloride

Position [°2Theta] (Copper (Cu))10 20 30

Counts

0

40000

160000

360000

Primary Quartz Peak

Secondary Quartz Peak

Primary Silver Peak


NIOSH 7500 - External Standard Method

• Create standards from a pure mineral

• Construct a calibration curve

• Compare unknown samples to known standard

results to determine silica quantification


Calibration Standard Data

100 µg Qtz

10 µg Qtz

5 µg Qtz

25 µg Qtz

Blank

250 µg Qtz

50 µg Qtz

Quartz Detection Limit2.5 µg Qtz


XRD Method Potential Interferences

• Mica*

• Potash

• Feldspars*

• Zircon

• Graphite

• Aluminosilicates

Best way to determine interferences: collect a bulk settled dust sample or send the bulk material in

question for XRD analysis for phase identification.


Lower LOQ Analysis

• Detection limit reduced by 50%- 2.5 mg vs 5.0 mg

• Accomplished through advanced instrumentation and software upgrades

• Requires additional sample prep and analysis

• AIHA LAP Approved

• Uniquely available from RJ Lee Group


Standard vs. Enhanced Spectral Analysis

Standard analysis 5.0 mg/filter

Enhanced analysis 2.5 mg/filter


Advantages of Lower LOQ

• Low sample volume on filter- Short duration sample event- “Clean” working environment

• Requirement for numerical reporting below industry standard

• Environmental (ambient/fence line) monitoring


RJ Lee Group, Inc.

350 Hochberg Road, Monroevi l le, PA 15146

Tel : (724) 325-1776 | Fax: (724) 733-1799

LABORATORY REPORT

ABC Company

1 Industrial Way

Pittsburgh, PA 15200 REPORT DATE June 4, 2014

ATTENTION: Crystal N. Silica SAMPLES RECEIVED May 30, 2014

TELEPHONE: 724-XXX-XXX RJ LEE GROUP JOB NO. PA30052014001

CLIENT JOB NO. N/A

ANALYSIS: Respirable Dust and Crystalline Free Silica Dust on 5 µm PVC Air Filters PURCHASE ORDER NO: N/A

METHODS: Gravimetry, NIOSH 0600 and X-Ray Diffraction, NIOSH 7500

LOD: 0.005 mg Quartz , Cristobalite, and Tridymite 0.100 mg Respirable Dust

Air* Respirable Masses of Free Weight Percentages of Airborne Dust

Sample Identification Volume Dust Mass Silica Minerals (mg/filter) Crystalline Silica Minerals Concentrations (mg/m3)

Client I.D. RJ Lee Group (liters) (mg/filter) Quartz Cristobalite Tridymite Quartz Cristobalite Tridymite Respirable Quartz Cristobalite Tridymite

Sample A 001 1200. 0.500 0.500 < 0.005 < 0.005 100.0 < 1.0 < 1.0 0.417 0.417 < 0.004 < 0.004

Sample B 002 1200. 0.500 0.250 < 0.005 < 0.005 50.0 < 1.0 < 1.0 0.417 0.208 < 0.004 < 0.004

Sample C 003 1200. 0.500 0.150 < 0.005 < 0.005 30.0 < 1.0 < 1.0 0.417 0.125 < 0.004 < 0.004

Sample D 004 1200. 0.500 0.100 < 0.005 < 0.005 20.0 < 1.0 < 1.0 0.417 0.083 < 0.004 < 0.004

Sample E 005 1200. 0.500 0.050 < 0.005 < 0.005 10.0 < 1.0 < 1.0 0.417 0.042 < 0.004 < 0.004

Blank 006 N/A < 0.100 1.050 < 0.010 < 0.010 N/A N/A N/A N/A N/A N/A N/A* Supplied by the client.

N/A Not Applicable

Air volume during a worker’s

shift

Mass of material on filter from

micro-balance

Mass of mineral

Mass of total dust× 100

Mass

Air Volume× 1000

Standard Report Overview


• Balance

– Calibration – daily

– Gravimetric test samples

• Calibration Curve

– Reanalyze and re-measure standards (every 3 mos.)

– CCV – Continuing Calibration Verification – Set of standards run after every 10th sample

• To ensure the calibration curves remain accurate

– RL – Reporting limit – Set of standards run daily

• To ensure that tube intensity is strong enough to see the RL (0.5µg)

• Sample Preparation

– Blanks – every day

• To check for cross contamination between samples during preparation

• Analysis

– 10% of unknown samples are re-measured by a second analyst

– 10% of CCVs and RLs are re-measured by a second analyst

• Audits

– AIHA audit – every 2 years

– Internal audits – annually

Quality Assurance


Lab Considerations

• Laboratory Selection– Sample preparation per method considerations

– Capability to address interferences

– Quality assurance and accreditation

– Detection limits

– Sampling guidance and support

• Technology Advancement– Sample concentration and sampling methods

– Advances in instrumental analysis / optimization


Marc Hugus: [email protected]

RJ Lee Group

Using the power of science to prove your products safe and

environmentally friendly

mailto:[email protected]

respirable crystalline silica (rcs) hugus.pdf · respirable crystalline silica (rcs) understanding...

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