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The Cohen Group Newsletter - Volume 6  Issue 1, Article 4.  January 2004

Proposed Changes to Cal/OSHA Airborne Contaminants Standard

Joy E. Fleming, MPH

 The Cal/OSHA Standards Board discussed the proposed changes to Title 8, §5155, Airborne Contaminants. The existing Section 5155, also referred to as Permissible Exposure Limits (PELs) for Chemical Contaminants, established minimum requirements for controlling employee exposure to specific airborne contaminants. Cal/OSHA stated that the purpose of the amendment to Section 5155 is to regulate employee exposure to toxic materials.

The airborne contaminants standard was last updated and amended between March 1997 and January 2001. Cal/OSHA stated, "Since that time, the body of information and the understanding of harmful effects of the substance listed in Section 5155 and others not listed there have changed," which resulted in the Airborne Contaminants Advisory Committee meeting between May 2001 and November 2002 to work on a series of revisions. The latest proposal is based on changes the American Conference of Governmental Industrial Hygienists (ACGIH) made to its Threshold Limit Values (TLVs) during the years 1997 through 2001. The substances for which TLVs were changed during this period provided a base list of substances for review and development by the advisory committee for the proposal.

Revisions to existing exposure limits are proposed for nearly 20 compounds listed in Table AC-1 and about 8 compounds are considered for addition. For most of the substances, the committee’s recommendations agreed with the rationale and limits set by the ACGIH but for 10 substances the committee used a different basis not in agreement with the ACGIH limits. Cal/OSHA stated that the Advisory Committee’s recommendations were made on the basis of consensus of opinion among the members. The substances that have proposed limits that are different than the ACGIH TLVs are presented in the following list.

Acetone – PEL is proposed to be lowered from 750 parts per million (ppm) to 250 ppm, which differs from the ACGIH TLV of 500 ppm. Short Term Exposure Limit is proposed to be lowered from 1000 ppm to 500 ppm, which differs from the STEL-TLV of 750 ppm.

Beryllium and Beryllium compounds – PEL is proposed to be lowered from 0.002 mg/m³ to 0.1 µg/m³ as total dust, which differs from the current ACGIH TLV of 0.002 mg/m³ as total dust and the proposed change to the TLV of 0.2 ug/m³ as an inhalable fraction.

2-Butoxyethanol – PEL is proposed to be lowered from 25 ppm to 10 ppm, which differs from the ACGIH TLV of 20 ppm.

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

Glutaraldehyde – Ceiling limit is proposed to be lowered from 0.2 ppm to 0.015 ppm, which differs from the ACGIH TLV of 0.05 ppm.

Methyl Methacrylate – PEL is proposed to be lowered from 100 ppm to 20 ppm, which differs from the ACGIH TLV of 50 ppm.

Molybdenum, soluble compounds, as Mo – PEL is proposed to be lowered from 5 mg/m³ total dust to 0.1 mg/m³ respirable fraction, which differs from the ACGIH TLV of 0.5 mg/m³ respirable fraction

Propylene oxide – PEL is proposed to be changed from 20 ppm to 1.0 ppm, which differs from the ACGIH TLV of 2 ppm.

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

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

Explanations for the differences in PELs versus the ACGIH TLVs can be found in the Initial Statement of Reasons issued by the Occupational Safety and Health Standards Board which is available on their website, www.dir.ca.gov/oshsb. Understand that these changes remain proposed and have not yet been adopted.