Henshaw, an industrial hygienist by training, has had his sights on updating the PELs all along, according to some Washington sources.

"How we'll do this I don't know, but we've got to do it, and we must be prepared to put politics aside and compromise," he said.

Henshaw might get help from Congress and others outside the agency. The idea is being floated on Capitol Hill that federal legislation might be the only way to update the PELs. OSHA has been stymied in past efforts to reduce exposure limits for hazardous chemicals by legalities.

A coalition of representatives from labor, industry and the American Industrial Hygiene Association is trying to craft a legislative approach that circumvents OSHA's regulatory roadblock.

It may take several years, if anything pans out at all, but stay tuned for more developments. If it's a pet project of the OSHA chief, it's not going away.