Ontario recently introduced new occupational exposure limits (OELs) for polyvinyl chloride and butenes along with 34 updates to existing OELs.

The Ministry of Labour (MOL) began annual reviews of OELs in 2004. These reviews are based primarily on allowable exposure standards established by the American Conference of Governmental Industrial Hygienists (ACGIH). These standards are designed to restrict worker exposure to hazardous substances.

In addition to new OELs for polyvinyl chloride and butenes, updates that will take effect on July 1, 2010 include:

• revisions to existing limits or information listings for 23 substances, and
• withdrawl of specific exposure limits for 11 substances that will be regulated either under a different substance or calculation method or because the ACGIH found a lack of information to support an OEL.

 Note: A link to the specific details for these updates from the MOL is provided below.

The use of OELs recommended by the ACGIH remains a concern for many including the Ontario Federation of Labour (OFL). "Much evidence points to the fact OELs established by the ACGIH protect the interest of employers, rather than the health of workers," says Vern Edwards, OFL director, health, safety and environment.

Also troubling is the use of "allowable exposure levels" to carcinogens. The MOL's 2009 review process did propose a significant reduction to the OEL for beryllium and its compounds - a substance categorized by the International Agency for Research on Cancer (IARC) as carcinogenic to humans. To the disappointment of many, after the 2009 public consultation, this proposal was shelved along with a significant reduction to the OEL for sulphur dioxide.

The OFL and others continue to call for the mandatory substitution for carcinogens and certain other hazardous substances. They also continue efforts to have the precautionary principle, extended producer responsibility and toxics use reduction enshrined in occupational health and safety law (Ontario's new Toxics Reduction Act is an environmental law though may have important occupational exposure prevention outcomes - see link below for more details).

The MOL also announced the consolidation of 11 of the 12 designated substance regulations. Just like OELs, each designated substance regulation establishes an allowable level of exposure to a substances deemed to be particularly hazardous (i.e. lead and isocyanates). These regulations though go further by outlining steps required to control worker exposure.

The MOL claims the consolidation of designated substance regulations will maintain existing worker protections. Regulation 278/05, Asbestos on Construction Projects and in Building and Repair Operations will remain as a stand-alone designated substance regulation.

For our part the WHSC remains committed to developing and delivering information and training to raise awareness about harmful chemicals in the workplace and the prevention efforts aimed at eliminating or reducing worker exposure and environmental contamination in our communities.

Want to know more about the OEL updates/consolidation of designated substance regulations?

Want to know more about:

Precautionary Principle

Toxics Reduction Act (Ontario)

Toxics Reduction Regulation (Ontario)

Extended Producer Responsibility

Want to know more about TLVs established by the ACGIH?

Want to know about WHMIS and other related WHSC training and information services - call a WHSC training service representative at 1-888-869-7950 or a WHSC near you.