Health Hazards of Solvents

James E. Cone MD, MPH

and Karen Packard, RDH, MSThis presentation is made possible by a grant from the Association of Occupational and Environmental Clinics and the National Institute

for Occupational Safety & Health.

Module Goals

To provide an overview of occupational solvent exposure

To review potential health outcomes and public health prevention options.

To provide step by step approach to diagnostic testing and treatment of solvent-related diseases

To provide background information on specific solvents

To illustrate the diverse effects of solvents through cases involving solvent toxicity

What is a solvent?

Classes of Common Organic Solvents: aliphatic hydrocarbons amines cyclic hydrocarbons esters aromatic hydrocarbons alcohols halogenated hydrocarbons ketones aldehydes ethers

A solvent is a liquid at room temperature used to dissolve other substances

Permission to use photo requested from AIHA Lab Safety Committee

Scope of the Problem

Over 49 million tons of solvent chemicals are produced and used each year in the US alone.

Often exposure involves a mixture of solvents.

Permission requested from US Navy

Occupational Disease due to Solvents? 390,000 new cases of all types of

occupational disease appear annually in the US.

It is unknown how many of these cases may be related to solvent exposure.

Similar to other occupational diseases, 95% of all occupational solvent-related disease cases are never reported,

most are never recognized as being occupationally-related.

OccupationalEnvironmental Workplace solvents may also result in

exposures to neighborhood residents if discharged from workplaces without adequate controls.

Other hazards:– Fire or explosion– Improper storage or disposal

Used with Permission of

OccupationalEnvironmental Residual

perchloroethylene solvent may be present in freshly dry cleaned clothes

Properties of Solvents

Solubility

Non-flammability/ Flammability/ Explosivity

Volatility

Metabolism

Complex mixtures

Used with permission of Advanced Chemistry Development Co. Graphic

Routes of Solvent Exposure

Inhalation

Absorption

-skin

-mucous

membranes

Ingestion

InjectionJane Norling Graphic

Organ System Effects

Cor

el G

rap

hic

Biological Monitoring

For Example: Urine testing for:

– Benzene Phenol – Toluene Hippuric Acid, o-Cresol– Xylene Methyl Hippuric Acid– n-Hexane 2,5 hexanedione*

-References: • ACGIH Biological Exposure Indices* Not commercially available at this time

Corel Graphic

Occupations Exposed to Solvents Painters Construction workers Semiconductor workers Machinists / auto mechanics Manufacturing workers

– Glue, Paint, Chemical, Plastics– Rotogravure Printers, Metal Degreasers

Graffiti removers Refinery workers Manicurists Drycleaners Many others

Solvent Related Diseases Acute Intoxication Chemical Headache Chemical Hepatitis Chronic Toxic

Encephalopathy Hematological

Effects Renal Effects Reproductive Health

Effects Toxic Peripheral

Neuropathy

Bill Bowerman developed n-Hexane related peripheral neuropathy from glues used for running shoes

Dx of Solvent-Related Disease 10 Step Process

Certain conditions should trigger the thought that it might be solvent-related:

– Chemical hepatitis, peripheral neuropathy, chronic headache, chronic cognitive impairment, miscarriage, and asthma.

Corel Graphic

Dx: Step 1 - Medical & Exposure Records Prior medical records

Industrial Hygiene data

Labels, Material Safety Data Sheets (MSDS), Chemical Inventory Lists

OSHA reports

Dx: Step 2 - Exposure History Symptoms &

Exposure History Complete History &

Physical Examination

Specific job duties, solvent exposures

Exposure monitoring Frequency of acute

solvent intoxication episodes

Acute Solvent Intoxication -Stages

Narcosis impaired psychomotor

function as measured by reaction time, manual dexterity, coordination, or body balance

Anesthesia

Central nervous system depression

Respiratory arrest Unconsciousness

Dx: Step 3 - Medical History

Asthma

History of Blood Dyscrasias

Hearing loss

History of Psychological Problems– Prior to exposure– After exposure

Dx: Step 4 - Physical Examination

Focus on: Skin Eyes Gastro -

intestinal Neurologic

system Mental Status

Dx: Step 5 - Laboratory Tests

Screening Biological Indices Pathologic

Indices

NIOSH Database of Medical Tests for OSHARegulated Substances:http://www.cdc.gov/niosh/nmed/medstart.html

Corel Graphic

Dx: Step 6 - Other Testing Nerve Conduction

Studies

Color Vision

Hearing

Pontogram (blink reflex – facial and trigeminal nerve evaluation)

Peak flow

Dx: Step 7 - Site Visit“Walk Through” of Patient’s Workplace

Assess workplace and potential exposures

– Personal or area industrial hygiene sampling– Ventilation of worksite– Potential skin exposure

Obtain prior environmental test results, if available

Dx: Step 8 - Relationship?

Decide whether the the patient’s diagnosis is more likely than not work-related.

Is the latency period adequate?

Exposure data consistent?

Dx: Step 9 - Make the Diagnosis

Was the dose of the solvent exposure adequate, in your opinion, to cause the problem? (e.g., is there a history of acute intoxication episodes?)

OR Is patient particularly sensitive to the effects of solvents (e.g. increased individual susceptibility or acquired intolerance)?

Dx: Step 9 - Diagnosis

Rule out other diseases with similar outcomes:– e.g., Alcoholic Hepatitis/ Hepatitis B

Decide if a pre-existing condition exists that has been exacerbated.

File Clinician’s First Report, if required by State Law.

Dx: Step 10 - Disposition

Return to work

Modified duty / preclusions

Factors of disability– Objective/ Subjective

Vocational rehabilitation

Apportionment

Future medical care

Prevention of Solvent Exposures Elimination

Substitution

Engineering Controls

Administrative Controls – Isolation

Personal Protective Equipment

EducationUsed with permission from

Personal Protective Equipment Protective Clothing-Impermeable aprons

Gloves – Breakthrough time depends on type of glove, solvent exposure and activity.

Chemically resistant gloves: natural rubber, butyl rubber, chloroprene, nitrile, and fluorocarbon; or various plastics: polyvinyl chloride, polyvinyl alcohol, polyethylene

Permission requested from

Personal Protective Equipment-RespiratorsRespirator Program must include:

Training

Cleaning

Fit testing

Medical Clearance

Change of filters –schedule depends on exposure type and amount

Environmental pressures are often the primary cause of

solvent substitution.

Montreal ProtocolClean Air ActPollution Prevention (P2)

Additional Resources

Handouts Bibliography Web Sites

– Jonathan S Rutchik, MD, MPH Organic Solvents http://www.emedicine.com/neuro/topic285.htm

Acknowledgements: – Photos by Janet Delaney– Elizabeth Katz, MPH, CIH– Rosemarie Bowler, PhD– Public Health Institute, AOEC and NIOSH staff