OHS Canada Magazine

WorkSafeBC reviewing exposure limits for 24 substances, seeks stakeholder feedback

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November 27, 2023
By OHS Canada

Health & Safety british columbia OELs WorkSafeBC

WorkSafeBC is reviewing exposure limits (ELs) in British Columbia and is looking for stakeholder feedback on 24 substances.

Each year, the American Conference of Governmental Industrial Hygienists (ACGIH) publishes a list of substances for which they have set new or revised Threshold Limit Values (TLVs). A TLV is the airborne concentration of a chemical substance where it is believed that nearly all workers may be exposed over a working lifetime and experience no adverse health effects.

TLVs may be expressed as an 8-hour time-weighted average (TWA), 15-minute short-term exposure limit (STEL), or ceiling limit.

Before adopting new or revised TLVs published by the ACGIH, WorkSafeBC reviews relevant data on health effects and the availability of validated sampling methods. WorkSafeBC also consults with stakeholders on potential implementation issues, it said in a press release.

WorkSafeBC’s existing B.C. Exposure Limits (ELs) continue to be in effect until the Board of Directors makes a decision on which new or revised ACGIH TLVs to adopt as B.C. ELs. See additional information on WorkSafeBC’s EL review process.


24 substances

WorkSafeBC is proposing new or revised B.C. ELs for the following substances:

  • Chromium and inorganic compounds: Metallic Chromium, as Cr(0)
  • Cobalt and inorganic compounds, as Co
  • Cyclopentadiene
  • Dicyclopentadiene
  • Dicyclopentadiene, including Cyclopentadiene (8-hour TWA only)
  • Manganese, elemental and inorganic compounds, as Mn
  • Resin acids, as total Resin acids
  • Rosin core solder thermal decomposition products (colophony)
  • Styrene
  • 1,1,2,2-Tetrabromoethane
  • Tin and inorganic compounds, excluding Tin hydride, as Sn, Metal
  • Tin and inorganic compounds, excluding Tin hydride, as Sn, Oxide and Inorganic compounds
  • Tin and inorganic compounds, excluding Tin hydride and Indium tin oxide, as Sn

WorkSafeBC is proposing to retain the existing B.C. ELs for the following substances:

  • Dicyclopentadiene, including Cyclopentadiene (15-minute STEL only)
  • Formamide
  • Indium tin oxide, as In
  • Isobutyl nitrite
  • Methyltetrahydrophthalic anhydride isomers
  • Methyl vinyl ketone
  • Monomethylformamide
  • o-Phthalaldehyde
  • Propylene glycol ethyl ether
  • Styrene oxide
  • Sulfur pentafluoride
  • m-Xylene α,α’-diamine

Feedback can be provided online at https://www.worksafebc.com/en/resources/law-policy/discussion-papers/proposed-bc-els-2019-2020-2023-november?lang=en or by email at ohspolicyfeedback@worksafebc.com

The deadline to provide feedback is 4:30 p.m. on Friday, Feb. 2, 2024.


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