An “occupational exposure limit” means

• except with respect to lead sulfide, formaldehyde, sulphur dioxide, hydrogen sulphide and nitrogen dioxide and any other contaminant for which the Commission sets an exposure limit, a threshold limit value adopted by the ACGIH and set out in the ACGIH publication entitled 2016 Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices,
• with respect to lead sulfide, an exposure limit set at 0.15mg/m3 -TWA,
• with respect to formaldehyde, an exposure limit set at 0.5 ppm - TWA and 1.5 ppm - STEL,
• with respect to sulphur dioxide, an exposure limit set at 2 ppm (5.2mg/m3)– TWA and 5 ppm (13mg/m3) - STEL,
• with respect to hydrogen sulphide, a ceiling of 10 ppm (13.9mg/m3),
• with respect to nitrogen dioxide, an exposure limit set at 3 ppm (5.6mg/m3)– TWA and 5 ppm 9.4 mg/m3)– STEL, and
• with respect to any other air contaminant for which the Commission sets an exposure limit, the exposure limit set by the Commission; (limite d’exposition professionnelle)

TLVs is a registered trademark of the ACGIH (American Conference of Governmental Industrial Hygienists). Since the Committee recommended exceptions to the 2016 and 1997 TLVs, the term “threshold limit value” cannot legally be used for these exceptions. Hence a new definition for “occupational exposure limit” which replaces the need for a definition of “threshold limit value”.

Refer to the 2016 Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices to see if exposure level for substance in your workplace changed.

The American Conference of Governmental Industrial Hygienists (ACGIH) publishes a list of substances each year for which they have set new or revised threshold limit values (TLV). You can contact ACGIH to obtain the publication at the ACGIH website.

You will need to create a profile, and then request a PDF copy of the 2016 TLVs & BEIs. Once a profile is created, you can email customerservice@acgih.org. There is a fee of $25 USD per copy or per person using them.