Maybe I should weigh in on this too. I’ve been involved in most OSHA rulemakings going back to the late 1970s. OSHA has two types of standards – the “consensus” standards like the old ACGIH TLVs which Congress wrote into the OSH Act, and new standards set through rulemaking. The old TLVs are just exposure limits. The “rulemaking” health standards contain lots of other stuff – medical surveillance, environmental monitoring, education, recordkeeping, means of compliance, etc. Those standards are the best researched and most comprehensively justified on earth. They have to be, since every single one is challenged in court. When the agency publishes a proposed or final rule, the actual regulatory text is accompanied by hundreds of pages in the dense, small-print Federal Register detailing all the science, comprehensively analyzing how the substance is used and how workers may be exposed, providing a complete economic analysis, explaining and justifying every part of the regulation and responding to the comments OSHA gathered from stakeholders through the lengthy rulemaking process.

Over the years Congress has made the process even lengthier, by adding additional levels of review and additional requirements for analysis. And the courts have weighed in. In a decision regarding the OSHA benzene standard the Supreme Court rejected the industry’s argument that OSHA be compelled to do a cost-benefit analysis, but did require the agency to do a numeric risk assessment to ensure that the risk was “significant.”  The Court refused to define “significant,” but in a footnote opined that a significant lifetime risk lies somewhere between 1 in a thousand and 1 in a billion. Very helpful.

An earlier ruling at the appellate level (like I said, they all get challenged) established that a standard has to be “feasible,” which has come to mean that the industry taken as a whole has to be able to meet it through engineering controls and work practices, even if some firms can’t meet it. In practice, feasibility is what sets the limit, since the substances OSHA picks are toxic enough that the 1 in 1000 risk level is below the feasibility level.

The result of all this is that OSHA promulgates very few health standards. Anti-regulatory administrations tend not to promulgate any. The George W. Bush Administration set only one, for hexavalent chromium, and only because our union was able to win a court order compelling them (I’m proud to say). Even where the administration is willing to act, it takes years to complete a standard and the agency can only work on a couple at a time.

I say all this for three reasons: First, to agree with those who say 0 is the best number and ALARA the best principle for managing toxic chemicals, particularly carcinogens and mutagens.

Second, to support the OSHA staff. It ain’t their fault! They are fine dedicated public servants struggling to do their best in an incredibly difficult job.

Third, to drive home the point that this system is dysfunctional, and we need to fix it. OSHA is about to embark on a rulemaking for silica, the hazards of which were known by the Romans. If we are lucky, we’ll see the final standard in 2015. And if this system can’t effectively regulate common chemicals, imagine how it will respond to the products of nanotechnology or synthetic biology. At some point, in some better Congress, we will try to change this. I hope we have the support of working chemists.   

Mike Wright

Chris, et al.,

Just two more fast comments and then, uncharacteristically, I'll shut up.

1.  Rob asked for documentation about OSHA's opinion of their PELs.  The statement is the Federal Register at 58 FR 35337-35351, June 30, 1993 when OSHA had to formally reinstate the old PELs thus revoking both the upgraded levels and addition of new PELs on substances for which there were no standards in 1968:

"OSHA continues to believe that many of the old limits which it will now be enforcing are out of date (they predate 1968) and not sufficiently protective of employee health based on current scientific information and expert recommendations. In addition, many of the substances for which OSHA has no PELs present serious health hazards to employees."

How I wish you would all add this short paragraph to your explanations of air quality standards somewhere for students to really understand the issue.

2.  Please also let students understand that there is no air quality limit that is not "feasible" no matter how low it is set.  Then the only consideration is money. 

For example, if we have to use a two component urethane system in an open shop, I require the employer put our union workers in air-supplied respiratory protection to keep below the 0.005 ppm TLV for the isocyanates.  Once the employer has spent 4-5 large for the compressors and lines WHICH THEY SHOULD HAVE IN THE SHOP ANYWAY, it only cost about $100 more per employee than air-purifying systems. 

Done well, this system can keep the exposure to essentially zero.  And better yet, the employer can install local exhaust ventilation such as a walk-in sized spray booth.

The only balancing act, then is between money and workers health.  As the old union song goes:  Whose Side Are You On?

Monona