Sunday, June 1, 2014

Risk Based OELs

This blog is being published during the week of the AIHA Annual Conference in San Antonio, TX.   I do not know if that will be a good week for readers of this blog because of their potentially heightened professional involvement or a bad week because they will be tied up at the conference.   In any event I have chosen this topic for this week because of the importance of this subject matter.

This week’s blog is really the work of my friend and colleague Adam Finkel.   Adam worked at OSHA in the 1990s and was perhaps the earliest advocate for what has come to be known as Risk Based Occupational Exposure Limits (RBOELs).   I have discussed RBOELs in this blog before, to recap they are OELs that are set at some quantitative level of putative risk (1 in 1000 has been suggested) determined by the modeling analysis of toxicological data.   RBOELs have been used for carcinogens by the EPA and others for some time but Adam (and I and others) are proposing that it be used more broadly for all OELs with enough documentation to set an OEL.

Dr. Jimmy Perkins and I have been conducting a series of teleconferences with members of the professional community with a stake and standing in this process.  A few weeks ago Adam presented to this group.   I would be happy to send his full presentation (PowerPoint slide deck) to anyone who requests it at   In the meantime I am going to present some bullet points from his talk that I found particularly frank, to-the-point and compelling.  No one could ever accuse Adam of beating around the bush!

What do the various kinds of limits ACTUALLY tell the worker who knows (roughly) what concentration s/he is being exposed to, but wants to know how dangerous it is?

   The OSHA PELs actually indicate levels that lawyers and economists decided were economically feasible for most or all employers to meet!  There is lots of cutting-edge risk science in the Preambles to the PELs, but the numerical limits themselves reflect (anemic) determinations about feasibility. (the word “anemic” in this paragraph is a personal judgment based on my (Adam’s) 12 years at OSHA– every other word is, I assert, unimpeachable)

   The ACGIH TLVs indicate levels that very smart, energetic, and creative volunteers together decided met some unknown balance of “reasonable assurance of safety” and reasonable achievability in the workplace.  Every such judgment is chemical-specific, not generic.

   At concentrations above or below the PEL or TLV, no knowledge about how safe or how dangerous is or can be transmitted.

The leaders and rank-and-file of the occupational health world are estranged from risk assessment, and the rift is widening

  •     long-standing moral distaste for risk assessment among labor unions, OSHA, NIOSH, etc.;
  •     tendency to blame risk assessment for delays and failures in the regulatory process;
  •     belief among many in corporate OHS that risk assessment is “voodoo” (see next slide –presented in the full slide deck but not herein)
  •     (mistaken) belief that risk assessment is overly “conservative” (see any of 8-10 articles by Adam Finkel on this issue);
  •     unflatteringly defensive posture (“with us or against us”) from the TLV Committee and AIHA;
  •     rise (esp. internationally) of “control banding” and other qualitative “alternatives” to risk assessment

An Action Plan and Cost Estimate for Developing 200 RB-OELs:

Adam envisions a two-step process:

1.  Develop (via a consensus process or an “agree to disagree”         process) science-policy ground rules for proceeding to assess risks:

       which study(ies) to select;
       how to convert exposures across species;
       “reference person” parameters;
       dose-response defaults and process for supplanting them

2. “Turn the crank” for @ 200 common substances with serious and irreversible health endpoints.

Adam thinks this could be done with 10 people, one year, and $750,000.

Of course, there is considerably more technical detail available in the slides which, again, I will be happy to send to anyone who asks for them.

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