My reading of the proposed regulation is that “use as a laboratory chemical” would include use as a solvent in research laboratories. Their rationale for not banning it was essentially that laboratories have fume hoods, and are therefore probably able to use methylene chloride safely. I happen to agree with this logic, which is why I agree with Jennifer that requiring a supplied air respirator as the only form of is overkill, as is the requirement that “initial” exposure monitoring be performed every five years irrespective of use of engineering controls.

 

I’m also surprised by the PEL that they chose. We all know the inadequacies of OSHA’s existing PELs, but there are other regulatory/advisory bodies out there we can look to whose approaches are generally more protective. The Cal/OSHA PEL is 25 ppm, the ACGIH’s TLV is 50 ppm, and the EU’s OEL is 100 ppm. It’s not impossible that all three could have set values an order of magnitude or two too high, but it doesn’t seem very likely.

 

Chris