OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.

March 22, 1988

Mr. Edgar L. McGowan
Commissioner Department of Labor
Post Office Box 11329
Columbia, South Carolina 29211

Dear Mr. McGowan:

This responds to you letter dated February 4, to Karen Mann, Acting Regional Administrator in Atlanta, requesting clarification of OSHA policy relative to the adjustment of the permissible exposure limit (PEL) for benzene for extended workshifts. Your letter was forwarded to my office for response.

The current standard for benzene, reference 29 CFR 1910.1028 does not include a provision for the reduction of the PEL for extended workshifts. Sampling strategy, however should be appropriately modified to adequately evaluate employee exposure when extended workshifts are present. The 8 hour period expected to produce the worst or highest concentration of benzene must be identified and sampled. Employee exposure to benzene should be evaluated against the 8-hour time weighted average and the short term exposure limit.

I hope this information will be helpful to you.


Edward J. Baier
Directorate of Technical Support