While ozone repairs itself naturally, it’s a different story for heavily exposed workers.
From a front-page NYTimes story on workers sickened by poor ventilation in furniture factories:
… Businesses found nPB appealing partly because the E.P.A. had given it an endorsement of sorts by adding it to a list of chemicals that do not harm the ozone layer. But an unintended effect of that action was to allow sellers of the chemical to market it as federally approved, “nonhazardous,” green and worker-friendly.
As the chemical’s popularity grew, E.P.A. officials worried about its use in spray glues, especially in cushion-making factories where the agency had determined that even with “state of the art” ventilation, “nPB-based adhesives cannot be reliably used in a manner that protects human health.”
Environmental officials figured that OSHA, pressured by the Bush administration and Republican lawmakers to be more business-friendly, would not be capable of policing the growing threat. “OSHA is tough,” E.P.A. officials said, according to notes from a November 2006 meeting on concerns about nPB. “But their budget is small, and they are not going to crack down on small businesses.”
OSHA has never set a standard establishing safety limits on workers’ exposure to nPB. The E.P.A. recommended such a limit and considered banning the nPB glues, but it has yet to finalize the plan. It determined that most cushion companies using the glue had fewer than 100 employees, which meant they were less able to absorb the cost of another regulation.
“There just wasn’t the political will,” an E.P.A. official who was part of the decision-making said on the condition of anonymity… [Emphasis added]