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Exposure Limits (ELs)

The Occupational Health and Safety Regulation (OHS Regulation) states that the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLVs) are generally used to establish WorkSafeBC’s Exposure Limits (ELs) for hazardous chemical substances.

The ACGIH is a professional association of industrial hygienists and practitioners that publishes a list of chemical substances with new or revised TLVs every year.

TLVs refer to airborne concentrations of chemical substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed, day after day, over a working lifetime, without adverse health effects. These exposure limits may include an 8-hour time-weighted average concentration, a short term (15-minute) exposure limit, or a ceiling limit.

Determining WorkSafeBC’s ELs

Section 5.48 of the OHS Regulation provides for the adoption of new or revised ACGIH TLVs as B.C. ELs, except as otherwise determined by WorkSafeBC. B.C. ELs that differ from the ACGIH TLVs are presented on the Table of Excluded Substances in Occupational Health and Safety (OHS) Policy Item R5.48-1 of the Prevention Manual.

The EL review and adoption process is set out here.

WorkSafeBC’s Exposure Limit Review Committee (ELRC) is responsible for reviewing the exposure limits provided for in Policy Item R5.48-1 of the Prevention Manual, as well as the new or revised TLVs recommended by the ACGIH. The ELRC makes recommendations as to which TLVs should be adopted as B.C. ELs. In reviewing the TLVs, the ELRC considers the following criteria:

  • Whether there are health effects reported by the ACGIH TLV documentation and other peer-reviewed literature;
  • Availability of validated sampling methods at commercial laboratories in North America; and
  • Whether there are any other implementation issues, such as technical and economic feasibility.

WorkSafeBC also consults with stakeholders before the Board of Directors (BOD) makes a decision to adopt the ACGIH TLVs as B.C. ELs. When the ACGIH recommends a new or revised TLV, WorkSafeBC places the existing B.C. ELs for the specific chemical substance on the Table of Excluded Substances in Policy Item R5.48-1 of the Prevention Manual; this is to ensure that the new or revised TLVs are not adopted as a B.C. EL until the BOD makes its decision.

By utilizing the expertise, resources, and review process of the ACGIH and the ELRC, WorkSafeBC is able to ensure that B.C. ELs remain consistent with the current health research, technological advances and other changes affecting occupational health and safety and occupational environment.

Table of Exposure Limits

WorkSafeBC maintains a Table of Exposure Limits for Chemical and Biological Substances associated with the OHS Guideline G5.48-2 (Part 5) which lists all substances with a B.C. exposure limit prescribed under section 5.48 of the OHS Regulation. In addition to the exposure limits, the Table also lists the ACGIH and the International Agency for Research on Cancer (IARC) notations relevant to section 5.57 of the OHS Regulation as a one-stop document to make it easier for stakeholders to reference.

E-Limit search tool

Our E-Limit search tool houses key information related to B.C. exposure limits in one location. You can use it to quickly search for any substance included in the Table of Exposure Limits. The search results provide information on:

  • Chemical names and CAS numbers
  • B.C. exposure limits
  • Associated health hazard notations and designations referenced in the OHS Regulation
  • Key regulatory requirements
  • Definitions to terminology associated with exposure limits

You can search multiple ways, using terms like the chemical name, CAS number (with or without hyphens), or health hazard (e.g., cancer, sensitizer, reproductive toxin, 2A, IARC). To learn more, please see our E-Limit frequently asked questions.

Search E-Limit


Please note that E-Limit is not designed to replace the judgment of qualified professionals. Always consult an occupational hygienist or an occupational health and safety professional if you need help interpreting an exposure limit. The tool is not intended to provide guidance on control measures to eliminate or minimize chemical or biological exposures in the workplace. It’s designed specifically for British Columbia and does not include the regulatory exposure limits for other jurisdictions.

EL announcements

A list of announcements regarding WorkSafeBC’s ELs are referenced below:

BOD Decisions on New and Revised ELs

Other previous changes to the Table of Excluded Substances in Policy Item R5.48-1 of the Prevention Manual

EL references

A list of references regarding WorkSafeBC’s ELs are referenced below: