OSHA has hundreds of permissible exposure limits or PELs for chemical hazards. These limits specify how much of various chemicals workers are allowed to breathe eight hours a day five days a week.

LIUNA General President Terry O’Sullivan
“Relying on OSHA’s stamp of approval, many people assume these PELs define a safe level of exposure,” says LIUNA General President Terry O’Sullivan. “Unfortunately, that’s not the case.”
OSHA implemented its PELs system in 1970 using consensus standards that today are no longer considered valid. As a group, they need to be updated (some have been updated by NIOSH or other organizations), but OSHA’s standard setting process is so broken that there is absolutely no chance of that happening. OSHA is left enforcing standards that everyone knows are not safe. So what should be done?
The solution OSHA has come up with is more honesty and transparency about the problem. In October, OSHA hosted a new webpage – Permissible Exposure Limits: Annotated Tables – that for the first time publicly admits that its standards are not safe. The web page shows a side-by-side comparison of the OSHA PELs with NIOSH’s recommended exposure levels (RELs), Cal-OSHA’s PELs and the threshold limit values (TLVs) of the American Conference of Governmental Industrial Hygienists (ACGIH). Compared to OSHA, Cal-OSHA has a much quicker process for updating its PELs, and ACGIH updates several TLVs every year.
OSHA’s new table shows just how bad its PELs are. Below are some examples (unless otherwise specified, limits are in parts per million (ppm) over an eight-hour day):
Substance | OSHA PEL | CAL/OSHA PEL | NIOSH REL | ACGIH TLV |
---|---|---|---|---|
Acetone | 1000 | 500 | 250 | 500 |
2- Butoxyethanol | 50 | 20 | 5 | 20 |
Carbon Monoxide | 50 | 25 | 35 | 25 |
Chloroform | 50 (ceiling) | 2 | 2 (60 min) | 10 |
2- Ethoxyethanol (Cellosolve) | 200 | 5 | 0.5 | 5 |
Toluene | 200 | 10 | 100 | 20 |
Trichloroethylene | 100 | 25 | 2 (ceiling) | 10 |
“So,” says O’Sullivan, “next time someone says, ‘Don’t worry. Your exposure is below the OSHA limit,’ check OSHA’s website and explain that the PEL may not be the right yardstick to measure safety. Until Congress gives OSHA the authority to update all of its exposure limits, the agency’s new comparison site is the best option for assessing real safety. ” It is up to companies to choose between real safety or mere compliance.
Along with its comparison site, OSHA simultaneously published a second useful site – Transitioning to Safer Chemicals: a Toolkit for Employers and Workers – explaining how to substitute safer chemicals for more toxic ones.
[Scott Schneider is the LHSFNA’s Director of Occupational Safety and Health.]