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Chemical Exposure Campaign Specific Questions
Q.
How do I know whether an agent has an occupational exposure level under Ontario
Regulation 833?
A.
Review Section 3 and 8 of the SDS – Composition/Information on Ingredients
Compare this list to the Chemical Abstracts Service (CAS) number listed for each ingredient to
the chemicals in O. Reg. 833 (chemicals are often known by multiple names, but the CAS# does
not change)
– Current occupational exposure limits for Ontario workplaces under Regulation 833
Q.
If a chemical or ingredient is not regulated in Ontario, do I still need to have safety
measures in place?
A.
If Ontario does not have a specific OEL, (for example Metal Working Fluids) but is still hazardous,
it is the employer's responsibility under the general duty clause (Section 25(2)(h) of the OHSA) to
ensure measures are in place to protect the workers
Q.
What if I have never done air sampling? Who provides these services?
A.
Consult a qualified individual, such as a Registered Occupational Hygienist (ROH) or a Certified
Industrial Hygienist (CIH), to assist in conducting the air sampling. WSPS has specialized
consultants with this expertise. The Occupational Hygiene Association of Ontario (OHAO) also has
a Consultant's Directory.
Q.
What if the air sampling I did was a few years ago?
A.
Depending on results, best practice could be to conduct air sampling at a frequency between 6
and 36 months. Workplaces with greater exposure hazards would require more frequent sampling.
Additionally, whenever there are changes in the work process, environment and practices which
may affect worker exposures to hazardous substances air sampling should occur to determine if
these changes effect exposure levels.
Q.
Will the MLITSD do the air sampling for me?
A.
The MLITSD may issue a requirement for the employer to conduct air sampling at their expense.
Occasionally and depending on the circumstances, MLITSD may conduct the air sampling for the
employer to determine compliance with the OHSA and its regulations.
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