Decision on the New and Revised B.C. Exposure Limits based on the 2020 ACGIH TLVs for Styrene

At its November 2024 meeting, WorkSafeBC’s Board of Directors (BOD) approved the adoption of the 2020 new and revised American Conference of Governmental Industrial Hygienists Threshold Limit Values (ACGIH TLVs) for styrene.

Effective January 8, 2025, styrene will be removed from the Table of Exposure Limits for Excluded Substances in Policy R5.48-1 of the Prevention Manual and the ACGIH TLVs will be assigned as B.C. exposure limits:

Substance	B.C. exposure limits
	8-hour time-weighted average limit	Short-term exposure limit	Ceiling limit
Styrene	10 ppm	20 ppm	—

Sincerely,

Lori Guiton
Director, Policy, Regulation and Research Department
WorkSafeBC