Occupational exposure limit (OEL)

An occupational exposure limit is the level of a substance that workplace safety rules say a worker’s exposure must not go beyond. A buyer of a manufacturing or trades business may meet the term in air-testing reports, ventilation records and regulator inspection orders. It sits within the wider topic of occupational health and safety compliance, and the employment risks a buyer can inherit are covered in what employment liabilities you inherit.

How three provinces set it

• Ontario: section 4 of Regulation 833 says that if an agent is listed in the Ontario Table, exposure shall not exceed the TWA, STEL or C (ceiling) value set out there. If it is not listed there but is in the ACGIH Table, that table applies. Under section 2(2), the regulation does not apply to certain designated substances and to asbestos in workplaces subject to their own regulations.
• Alberta: section 16(2) of the Occupational Health and Safety Code requires an employer to ensure a worker’s exposure to a substance listed in Schedule 1, Table 2 does not exceed its occupational exposure limits listed there.
• British Columbia: section 5.48 of the Occupational Health and Safety Regulation says that, except as otherwise determined by the Board, the employer must ensure no worker is exposed to a substance that exceeds the ceiling limit, short-term exposure limit or 8-hour TWA limit prescribed by ACGIH.

What to check or ask

Ask which substances are used on site and which limit table applies to each. Ask for exposure monitoring results and any regulator orders. This entry covers Ontario, Alberta and British Columbia only; check the rules where the workplace is.