Background:

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”). Three categories of TLVs are specified: 8-hour time-weighted average, short-term exposure limit, and a ceiling.

In accordance with the occupational exposure limit (“OEL”) review and adoption procedure, WorkSafeBC reviews the scientific data and availability of validated sampling methods, and consults with stakeholders on potential implementation issues prior to the adoption of the annual new or revised ACGIH TLVs. Until the Board of Directors (“BOD”) makes a decision on which of the annual new or revised ACGIH TLVs are adopted as BC OELs, the existing OELs for these substances continue to be in effect.

Board of Directors' Decision:

At the July 2011 meeting, the BOD provided their decision on the 2011 new and revised ACGIH TLVs for eight substances.

The BOD approved the adoption of the ACGIH TLVs as BC OELs for Acetic anhydride, Carbon black, Ethyl benzene, Methyl isopropyl ketone, Soapstone, and 4,4’-Thiobis(6-tert-butyl-m-cresol). Effective September 15, 2011, these six substances will be removed from the Table of OELs for Excluded Substances in Policy R5.48-1, and the ACGIH TLVs will be assigned as BC OELs as follows:

The BOD decided to maintain the following substances on the Table of OELs for Excluded Substances with no changes to their respective limits:

The reason for the BOD decision for the above substances is that there are no validated sampling methods for Maleic anhydride and 2,4-Pentanedione. There will be on-going monitoring of the availability of validated sampling methods for each of these substances.