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The Cohen Group Newsletter - Volume 7  Issue 3, Article 5.  October, 2005

Update: Proposed Changes to Cal/OSHA Airborne Contaminants Standard
By Joy E. Fleming

 From time to time, the Cal/OSHA Standards Board addresses proposed changes to Title 8, §5155, Airborne Contaminants. Section 5155, also referred to as Permissible Exposure Limits (PELs) for Chemical Contaminants, establishes minimum requirements for controlling employee exposure to specific airborne contaminants. This article is an update on Cal/OSHA’s latest proposed changes to the PELs.

In 2003, exposure limits for nearly 20 compounds listed in Table AC-1 were proposed to be revised with about 8 compounds considered for addition. The proposal drafted by the Airborne Contaminants Advisory Committee was based on changes made by the American Conference of Governmental Industrial Hygienists (ACGIH) to its Threshold Limit Values (TLVs) during the years 1997 and 2001. For most substances, the committee’s recommendations agreed with the rationale and limits set by the ACGIH. There were 10 substances where the committee used a different basis, not in agreement with the ACGIH limits and were proposed below the ACGIH TLV.

The 10 exposure limits that differed from the ACGIH TLVs were withdrawn from the 2003 proposal due to employer and manufacturer concerns presented at a special public meeting convened by the Division of Occupational Safety and Health (Division) in March 2004. The remaining chemicals listed in Table AC-1 for revisions or additions were adopted and became effective as of November 03, 2004.

In September 2005, the PELs originally proposed for 6 substances that differed from the TLVs were changed to levels consistent with the ACGIH TLVs based upon information received at the additional meeting and review. These substances were Acetone, 2-Butoxyethanol, Gluteraldehyde, Methyl methacrylate, Molybdenum (soluble compounds as Mo) and Propylene oxide. Exposure limits for 4 chemicals were also proposed to be lowered to correspond with the ACGIH TLVs and these were Crotonaldehyde, Hexachlorobenzene, Methyl bromide and Methyl 2-cyanoacrylate. The PEL for n-Hexane was proposed to be changed by adding a Skin designation. A "Skin" notation means that skin absorption is another route of exposure that must be considered. Two new PELs for Bis (Dimethlaminoethyl) ether (DMAFE) and 1-Hexene were proposed to be added and correspond with the ACGIH TLVs. Four substances remain in the proposed list to have limits that are different than the published ACGIH TLVs and are presented in the following list.

Beryllium and Beryllium compounds – PEL was proposed to be lowered from 0.002 mg/m³ (2µg/m³) to 0.2 µg/m³ as total dust, which differs from the current ACGIH TLV of 0.002 mg/m³ as total dust and the 2005 intended change for the TLV to 0.2 µg/m³ as an inhalable fraction.

Epichlorhydrin – PEL was proposed to be lowered from 2 ppm to 0.05 ppm, which differs from the ACGIH TLV of 0.5 ppm.

1,3,5 Triglycidyl-s-Tranzinetrione - PEL was proposed as a new limit at 0.005 mg/m³, which differs from the ACGIH TLV of 0.05 mg/m³.

Vinylidene Fluoride – PEL was proposed as a new limit at 100 ppm, which differs from the ACGIH TLV of 500 ppm.

The two new PELs for 1,3,5 Trigylcidyl-s-trianzinetrione and Vinylidene fluoride were unopposed during the March 2004 advisory meeting and had no further changes amended to the proposal. Explanations for the basis of proposed changes to PELs, differences in PELs versus the ACGIH TLVs, and any concerns addressed in the 2004 advisory meeting can be found in the Initial Statement of Reasons issued by the Occupational Safety and Health Standards Board, which is available on their website, http://www.dir.ca.gov/oshsb. Understand that these changes remain proposed and have not yet been adopted.