Ontario has made important changes to some of its regulations relating to occupational health. Some Ontario workplaces will be affected by the changes, so IHSA has gathered the latest information on them.

Ontario Regulation 490 – Designated substances

Designated substances such as lead, silica, mercury, and isocyanates are particularly hazardous because they can cause strong allergic reactions, liver and lung problems, nervous system effects, and even types of cancer. All designated substances are regulated in Ontario and each must be assessed and controlled according to specific procedures.

This past summer, eleven of twelve designated-substance regulations were combined into one new regulation called Ontario Regulation 490/09 – Designated Substances. (Regulation 278 – Asbestos on Construction Projects and in Buildings and Repair Operations continues to be separate and must still be followed.) The regulations were combined to make compliance easier for employers who can now consult two regulations instead of twelve. Visit the e-laws website to read the new Designated Substances Regulation.

Ontario Regulation 833 – Control of exposure to biological or chemical agents

This past July, revisions were made to Regulation 833. This regulation sets out occupational exposure limits (OELs) for various hazardous chemicals in air. Here are some changes:

• 1. OELs are now found in two tables.
• Ontario Table in Regulation 833 – Approximately 135 OELs are listed in the regulation because these limits differ from those set out by the American Conference of Governmental Industrial Hygienists (ACGIH, 2009 Threshold Limit Values and Biological Exposure Indices).
• ACGIH Table in the booklet 2009 Threshold Limit Values and Biological Exposure Indices – For ACGIH OELs that were consistent with Ontario’s limits, the 2009 ACGIH Threshold Limit Values were adopted. You must now comply with these OELs.

• 2. New terms have been adopted:
• Time-Weighted Average (TWA)
• Short-Term Exposure Limit (STEL)
• Ceiling Limit (C)

The revised Control of Exposure to Biological or Chemical Agents Regulation and definitions can be found on the e-laws website.