Health Hazards of Solvents

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Health Hazards of Solvents

• James E. Cone MD, MPH
• and Karen Packard, RDH, MS
• This presentation is made possible by a grant
  from the Association of Occupational and
  Environmental Clinics and the National Institute
  for Occupational Safety Health.

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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

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What is a solvent?
A solvent is a liquid at room temperature used to
dissolve other substances
Classes of Common Organic Solvents
? aliphatic hydrocarbons ? amines ?
cyclic hydrocarbons ? esters ? aromatic
hydrocarbons ? alcohols ? halogenated
hydrocarbons ? ketones ? aldehydes
? ethers
Permission to use photo requested from AIHA Lab
Safety Committee
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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
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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.

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OccupationalçèEnvironmental

• 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
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OccupationalçèEnvironmental

• Residual perchloroethylene solvent may be
  present in freshly dry cleaned clothes

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Properties of Solvents

• Solubility
• Non-flammability/
• Flammability/
• Explosivity
• Volatility
• Metabolism
• Complex mixtures

Used with permission of Advanced Chemistry
Development Co. Graphic
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Routes of Solvent Exposure

• Inhalation
• Absorption
• -skin
• -mucous
• membranes
• Ingestion
• Injection

Jane Norling Graphic
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Organ System Effects
Corel Graphic
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Biological Monitoring

• For Example
• Urine testing for
• Benzene è Phenol
• Toluene è Hippuric Acid, o-Cresol
• Xylene è Methyl Hippuric Acid
• n-Hexaneè 2,5 hexanedione
• -References
• ACGIH Biological Exposure Indices
• Not commercially available at this time

Corel Graphic
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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

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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
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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
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Dx Step 1 - Medical Exposure Records

• Prior medical records
• Industrial Hygiene data
• Labels, Material Safety Data Sheets (MSDS),
  Chemical Inventory Lists
• OSHA reports

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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

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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

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Dx Step 3 - Medical History

• Asthma
• History of Blood Dyscrasias
• Hearing loss
• History of Psychological Problems
• Prior to exposure
• After exposure

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Dx Step 4 - Physical Examination

• Focus on
• Skin
• Eyes
• Gastro - intestinal
• Neurologic system
• Mental Status

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Dx Step 5 - Laboratory Tests

• Screening
• Biological Indices
• Pathologic Indices

NIOSH Database of Medical Tests for
OSHA Regulated Substances http//www.cdc.gov/nios
h/nmed/medstart.html
Corel Graphic
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Dx Step 6 - Other Testing

• Nerve Conduction Studies
• Color Vision
• Hearing
• Pontogram (blink reflex facial and trigeminal
  nerve evaluation)
• Peak flow

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Dx Step 7 - Site Visit

• Walk Through of Patients 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

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Dx Step 8 - Relationship?

• Decide whether the the patients diagnosis is
  more likely than not work-related.
• Is the latency period adequate?
• Exposure data consistent?

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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)?

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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 Clinicians First Report, if required by
  State Law.

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Dx Step 10 - Disposition

• Return to work
• Modified duty / preclusions
• Factors of disability
• Objective/ Subjective
• Vocational rehabilitation
• Apportionment
• Future medical care

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Prevention of Solvent Exposures

• Elimination
• Substitution
• Engineering
• Controls
• Administrative
• Controls
• Isolation
• Personal Protective Equipment
• Education

Used with permission from
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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
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Personal Protective Equipment-Respirators

• Respirator Program must
• include
• Training
• Cleaning
• Fit testing
• Medical Clearance
• Change of filters schedule depends on exposure
  type and amount

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Environmental pressures are often the primary
cause of solvent substitution.

• Montreal Protocol
• Clean Air Act
• Pollution Prevention (P2)

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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