Washington State University
Environmental Health & Safety Exposure Monitoring

Chemical Exposure Monitoring

An employee’s / student’s exposure to any regulated hazardous chemical shall be monitored if there is reason to believe exposure levels for that chemical exceed the regulatory limits (See Appendix A, Appendix B.).

Included in the list of regulated hazardous chemicals are specific substances with individual health standards. They are as follows:


(See Section II.N.1.b Listed Carcinogens)

  • 4-Nitrobiphenyl
  • Benzidine
  • Alpha-Napthylamine
  • 4-Aminodiphenyl
  • 4,4′-Methylene bis (2-chloroaniline)
  • Ethyleneimine
  • Methyl Chloromethyl Ether
  • Beta-Propiolactone
  • 3,3′-Dichlorobenzidine (and its salts)
  • Acetylaminofluorene
  • Bis-Chloromethyl ether
  • 4-Dimethylaminoazobenzene
  • Beta-Naphthylamine
  • N-Nitrosodimethylamine


(See Section II.N Carcinogens in Laboratories 1.c. and Appendix B – Carcinogens / Individual Health Standards that Applies)

  • Acrylonitrile
  • Butadiene
  • Cadmium
  • 1,2-Dibromo-3 chloropropane
  • Ethylene Oxide
  • Inorganic arsenic
  • Methylene Chloride
  • Vinyl Chloride


(See Appendix B – Specific Air Contaminates / Individual Health Standards that Applies)

  • Asbestos
  • Benzene
  • Formaldehyde
  • Hexavalent Chromium
  • Lead
  • Methylenedianiline
  • Thiram

Events or circumstances

that might reasonably constitute overexposure to a hazardous chemical and require monitoring include:

  • An employee / student is working with a hazardous chemical outside a fume hood and manifests symptoms, such as a headache, rash, nausea, coughing, tearing, irritation or redness of eyes, irritation of nose or throat, dizziness, loss of motor dexterity or judgment, and
  • The symptoms are consistent with the safety data sheet or other references. Some or all of the symptoms disappear when the person is taken away from the exposure area and breathes fresh air, and the symptoms reappear soon after returning to the exposure area; or
  • Two or more persons in the same work area have similar complaints;
  • An employee / student handled toxic solvents, corrosives, or other volatile chemicals in a defective fume hood or in a poorly ventilated room;
  • An employee / student had direct skin or eye contact with a hazardous chemical (e.g., employee reports signs or symptoms of dermal conditions associated with formaldehyde exposure);
  • Previous monitoring was conducted in the work area and results were below the regulatory limits; however, the process, procedure, or ventilation conditions (e.g., redesigns of fume hood) have changed; or
  • A hazardous chemical leaked, spilled, or was otherwise released in an uncontrolled manner;

Chemical Monitoring

If you suspect an over exposure to a hazardous chemical or work with any of the substances listed above (Listed Carcinogens / Specific Carcinogens / Specific Air Contaminants) and an evaluation has not been performed, contact Environmental Health and Safety (EH&S) at 335-3041. EH&S will promptly investigate reported events and circumstances.

For additional information on exposure monitoring, see Fact Sheet – Chemical Monitoring and Sampling.

Upon investigation, EH&S will determine if exposure monitoring is required. On occasion, monitoring may not be required because previous monitoring records indicate exposure levels below the regulatory limits. On a case by case basis, some of those records may or may not be used as representative samples to support the belief that exposure levels are below the regulatory limits. Therefore, if previous monitoring was performed in a work area and the results were below regulatory limits but conditions have changes (e.g., amount and concentration of chemical, ventilation design, process, etc.), contact EH&S for an evaluation.