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 https://www.osha.gov.

June 24, 1992

Kathleen A. Reamv
Head Department of Government Relations
and Science Policy
American Chemical Society
1155 Sixteenth Street, N.W.
Washington, D.C. 20036

Dear Ms. Ream:

This is in response to your letter of April 29 to Mr. James F. Foster, Director of the Office of Information in the Occupational Safety and Health Administration (OSHA). Your letter was forwarded to the Directorate of Compliance Programs for response.

In your letter you requested written confirmation that the Final Rule on Process Safety Management (PSM) of Highly Hazardous Chemicals published in Volume 57, Number 35 of the Federal Register on Monday, February 24, 1992 does not apply to laboratory and research operations. Also, you indicate in your letter that "an OSHA staff member stated over the phone that, because of the Laboratory Standard's coverage, these operations were not intended to be subject to the Process Safety Management rule."

A "laboratory" as defined in 29 CFR 1910.1450(b) is not subject to the PSM standards at 29 CFR 1910.119. "Laboratory" means a facility where the "laboratory use of hazardous chemicals" occurs. It is a workplace where relatively small quantities of hazardous chemicals are used on a non-product basis. Relatively small quantities are quantities less than the threshold quantities of highly hazardous chemicals listed in Appendix A of the PSM.

By 29 CFR 1910.119(b), "process" means any activity or combination of activities including the use, storage, manufacture, handling or on-site movement of highly hazardous chemicals to which the PSM standards apply. Also by 29 CFR 1910.119(b), "facility" means the buildings, containers or equipment which contain a process. Although not applicable to laboratories, the PSM standards are applicable to other site facilities which contain processes involving highly hazardous chemicals at or above the threshold quantities.

A directive is being developed by OSHA to provide interpretive guidance and inspection procedures to our field staff. The interpretations and clarifications addressed in this letter will be incorporated in that directive. We will send you a copy of the directive when it is completed in the near future.

Thank you for your interest in occupational safety and health. If we can be of further assistance please do not hesitate to contact us.


Patricia K. Clark, Director
Directorate of Compliance Programs