Ministry of Labour opens consultation on proposed changes to Ontario’s occupational exposure limits

9 Apr 2018

The Ontario Ministry of Labour has posted a list of proposed changes to the occupational exposure limits (OELs) regulating Ontario workplaces (Regulation 833). These changes include updates to the OELs of a number of hazardous workplace substances, including formaldehyde, toluene diisocyanate, and cobalt containing tungsten chloride. A full list of affected substances is available here:

Additionally, the Ministry of Labour is proposing to add a new OEL for diesel engine exhaust into Regulation 833. Diesel engine exhaust is classified as a definite human carcinogen (Group 1) by the International Agency for Research on Cancer. Currently, diesel exhaust is only regulated in the mining industry in Ontario (Regulation 854; 400 ug/m3, measured as total carbon) but there is no OEL that applies to other Ontario workplaces. The Ministry is proposing to adopt a limit of 160 ug/m3 (total carbon) in Regulation 833. This proposed limit is based on the exposure limit set by the US Mining Safety and Health Administration for diesel particulate matter in the US mining industry. This is an important first step in controlling exposure to diesel engine exhaust. Moving forward, OCRC recommends further lowering the OEL to 20 ug/m3 (elemental carbon) for the mining industry and 5 ug/m3 (elemental carbon) for other workplaces.

Finally, the Ministry proposes to adopt the IRSST’s Guide for the adjustment of permissible exposure values (PEVs) for unusual work schedules. Occupational exposure limits are generally calculated for a standard eight-hour work shift and 40 hour work week. Adjustments need to be made in the case of irregular shift patterns that may result in longer work hours. The IRSST’s Guide offers a more nuanced adjustment strategy than the Ministry’s current method, to ensure that workers with irregular schedules are protected to the same level as those working a conventional shift schedule.

The consultation period ends on May 4, 2018. For more information on the proposed changes, or to participate in the consultation, visit the Ministry of Labour website.