Ontario Proposing New and Revised Occupational Exposure Limits

• Issued: July 19, 2010
• Content last reviewed: July 2010
• See also: Bulletin

Ontario currently has Occupational Exposure Limits (OELs) for over 725 hazardous biological and chemical substances.

The 2010 consultation will be the seventh review under the ministry’s process to keep OELs up-to-date. Commencing today, a 60-day consultation on proposed changes for 2010 is launched.

As a result of the American Conference of Governmental Industrial Hygienist (ACGIH) and its recommended changes to limits for 2010, MOL is proposing to adopt new or revised OELs for 12 substances. These changes include:

• Addition of one substance to regulation (Citral).
• Revisions to exposure limits or listings for 10 substances currently regulated.
• Withdrawal of the listing and specific exposure limit for one substance, Tantalum, metal and oxide (total dust), on the basis that ACGIH concludes there is insufficient data or information to support an OEL. This substance will be regulated by the OELs for Particles (Insoluble or Poorly Soluble) Not Otherwise Specified (PNOS).

In addition to the changes noted above, the Ministry of Labour is also proposing to:

• Add a specific listing and limit for “Methyl Isocyanate” in Regulation 833 – Control of Exposure to Biological or Chemical Agents and Regulation 490/09 – Designated Substances as per ACGIH. This proposed change is not a result of ACGIH 2010 recommendations but is a case where Ontario could better address workplace exposures and align with ACGIH by adopting the limit for this substance.
• Withdraw the Short Term Exposure Limits for 22 substances listed in the Ontario Table in Regulation 833 and regulating short-term exposures through the application of excursion limits determined in accordance with the rules set out in paragraph 3 of section 4 in Regulation 833.

Stakeholder input is an essential part of the OEL updating process. Stakeholders are invited to submit comments on any or all of the proposed OEL changes. Specific concerns should contain a clear description of the rationale and appropriate documentation.

Where an exposure limit for a hazardous substance has not been recommended and is not under consideration by the ACGIH at this time, stakeholders are invited during this consultation period to nominate the substance for development of an OEL. The submission should include a proposed limit and supporting documentation used by a jurisdiction that has adopted the proposed limit.

The 60-day consultation period ends September 17, 2010. Submissions may be mailed, faxed, or sent electronically to the following addresses: