One of the topics OSHA says it will have an open ear to at the February 11 public “listening” session held to help OSHA leadership assemble its priorities is the on-going saga of how to update chemical exposure limits. Here’s how OSHA framed the issue in its “listening session” announcement:

“In the late 1980s, OSHA and its stakeholders worked together to update the Permissible Exposure Limits (PELs) (exposure limits for hazardous substances; most adopted in 1971), but the effort was unsuccessful. Should updating the PELs be a priority for the agency? Are there suggestions for ways to update the PELs, or other ways to control workplace chemical exposures?

OSHA chief Dr. David Michaels, in his one public speech to date, said,” There's an enormous chasm to bridge between the ideal future and the imperfect present. Today we suspect that at least a couple of thousand high-use chemicals out there may present some threat to worker health. Yet, OSHA currently regulates about 500 chemicals, based mostly on science from the 1950s and 1960s. How many chemical standards has OSHA issued in the past 12 years? Two - and one of these two only came about because of a court order! We haven't been keeping up with the science.

”So, not only are we lacking critical information about the hazards of many chemicals, but we have virtually no information about the hazards of chemical mixtures”.

Industrial hygienist Dan Markiewicz, writing in a February article in ISHN magazine, said, “Occupational exposure limits (OELs) such as the regulatory-based OSHA PEL or health-based ACGIH® TLV® are established as a risk management tool to help EHS pros determine if chemical exposure to workers is acceptable. The future of these OELs, however, is bleak.

“Together the number of PELs, TLVs®, AIHA WEELs, and NIOSH RELs account for only about one percent of the 80,000 chemicals in U.S. commerce. Most PELs are based upon 1968 TLVs®. OSHA developed fewer than 20 new PELs in 40 years – a pattern unlikely to change. TLV® development is no longer sustainable under ACGIH®’s current budget. It costs ACGIH® about $50,000 to develop or revise a single TLV®. Primarily because of legal costs to defend the TLV® process, ACGIH® experienced operating losses of about $600,000 through 2006-2008. Adding salt to wounds, as currently written, OSHA’s proposed rule to align hazard communication with GHS (Globally Harmonized System of Classification and Labeling of Chemicals) will delete the TLV® reference from safety data sheets (SDS)

“Most EHS pros now realize that EU REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals) legislation impacts chemical management in the U.S. REACH requires manufacturers and importers of chemicals into Europe to determine and communicate a “Derived No Effect Level” (DNEL). A DNEL is defined as “the level of exposure above which humans should not be exposed.

“There may be several DNELs, depending upon mode of effect, for a single chemical. The way DNELs are determined means they will usually be lower, sometimes significantly lower, than an OEL. Also, be aware that REACH requires other exposure limits besides the DNEL that this article does not discuss.

“A DNEL is required for all regulated chemicals in production volumes over 10 tons per year. As REACH evolves, the DNEL will become the most prominent exposure level for chemicals. DNELs will begin to appear in public lists and SDS in 2010. EHS pros in the U.S. will encounter DNELs as GHS evolves.”

The American Industrial Hygiene Association recently put out the word that “while we are aware that OSHA has limited resources available to update the PELs on an individual basis, we do not believe the agency can sit idly by and not address the issue”.

How can updating decades-old exposure limits not be a priority?