2017 New or Revised ACGIH Threshold Limit Values and B.C. OELs

The Occupational Health and Safety Regulation (OHSR) provides that Occupational Exposure Limits (OELs) for hazardous chemical substances are generally determined with reference to the Threshold Limit Values (TLVs) set by the American Conference of Governmental Industrial Hygienists (ACGIH).

Each year, the ACGIH publishes a list of substances for which they have set new or revised TLVs. When the subtances are adopted, WorkSafeBC refers to these TLVs as OELs.

An OEL is the maximum allowed airborne concentration for a particular substance from which nearly all workers are believed to experience no adverse health effects over a working lifetime. OELs may be set out as an 8-hour time-weighted average concentration, short-term exposure limit, or ceiling limit.

When the ACGIH publishes its annual list, WorkSafeBC adds any changed or new OELs to the Table of Occupational Exposure Limits for Excluded Substances in OHS Policy R5.48-1. By doing so, WorkSafeBC ensures that the existing OELs for these substances continue to be in effect until WorkSafeBC’s Board of Directors makes a decision on adoption of the changes. This gives WorkSafeBC the opportunity to consult stakeholders prior to adopting new or revised ACGIH OELs.

The ACGIH has published the 2017 new or revised TLVs. The following substances, for which there are new or revised ACGIH TLVs, have been added to the Table of Occupational Exposure Limits for Excluded Substances in OHS Policy R5.48-1. The current B.C. OELs are maintained for the substances below until the BOD makes a decision on the adoption of their respective TLVs.

Acetamide Folpet
Isobutane Furfural
Cadusafos Hexylene glycol
Captafol Phthalic anhydride
Β-chloroprene Stearates
Ethylene glycol (aerosol) Tungsten as W, metal and insoluble compounds; soluble compounds

The ACGIH has also revised the TLVs for 2,4-dichlorophenoxyacetic acid and its esters, ethylene glycol (particulate and vapour), formaldehyde, and furfuryl alcohol. These substances are already listed in the Table of Occupational Exposure Limits for Excluded Substances and the current B.C. OELs are maintained.