Historical hexavalent chromium exposure limit

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

April 19, 1995

R. J. Barnhart, Ph.D.
American Chrome and Chemicals Inc.
[Recipient address omitted]
Dear Dr. Barnhart:

You requested clarification of OSHA's current permissible exposure limit (PEL) for occupational exposure to hexavalent chromium in general industry.

OSHA's current PEL for chromic acid and chromates is found in Table Z-2 (29 CFR 1910.1000). This table specifies a ceiling limit of 100 micrograms per cubic meter of air (1.0 mg/10 m(3)), which covers all forms of hexavalent chromium [chromium (VI)] measured as chromium (VI) and reported as CrO(3). The entry has been unchanged since published in 1971.

There is no health basis for a less protective limit. This correspondence replaces any earlier interpretations concerning the PEL.

OSHA's interpretation is that the PEL for chromium (VI) in general industry is a ceiling value of 100 micrograms per cubic meter of air (100 ug/m(3)), measured as chromium (VI) and reported as CrO(3), as it is published. In the construction industry, the PEL is 100 ug/m(3) as an eight-hour, time-weighted-average.

A copy of this letter will be placed in the Hexavalent Chromium Docket (H-054-a) for further reference. OSHA will be addressing this issue in our forthcoming rulemaking on chromium (VI). If you have any questions, please do not hesitate to contact me at 202-219-7075.

Sincerely,
John F. Martonik
Acting Director
Health Standards Programs