Archive Notice - OSHA Archive

NOTICE: This is an OSHA Archive Document, and may no longer represent OSHA Policy. It is presented here as historical content, for research and review purposes only.

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

January 8, 1993

Mr. Gregory E. Thompson
Law Offices of Daniel R. Thompson, P.C.
1620 "I" Street, N.W.
Suite 925
Washington, D.C. 20006

Dear Mr. Thompson:

This is in response to your letter of September 2, on behalf of your clients, the Flavor and Extract Manufacturers' Association of the U.S. and the Fragrance Materials Association of the U.S., to Patricia K. Clark, former Director of the Directorate of Compliance Programs. In your letter you requested a meeting to clarify the applicability of the Process Safety Management (PSM) of Highly Hazardous Chemicals standard, 29 CFR 1910.119, to flammable liquid processes at the worksites of your clients. In an October 29, telephone communication with Mr. Ronald Davies of my staff, you agreed, in place of a meeting, to accept a written interpretation, which follows.

In your letter you requested that OSHA answer the following question. Does the rule (at 29 CFR 1910.119(a)(1)(ii)(b)) exempt all flammable liquids stored or transferred which are kept below their normal boiling point without benefit of chilling or refrigeration, including, but not limited to, flammable liquids in atmospheric tanks?

The answer to your question is no, and the following is provided for clarification. The exemption is limited to flammable liquids stored in atmospheric tanks or transferred which are kept below their normal boiling point without the benefit of chilling or refrigeration. This exemption is applicable to flammable liquids in tanks, containers and pipes used only for storage and transfer (to storage), and not connected to a process or a process vessel. Similarly, stored flammable liquids in containers, including cans, barrels and drums, would be exempt from coverage by the PSM standard. We recommend you carefully consider the definition of "process" to determine further applicability of the PSM standard in situations where flammable liquids are stored in tanks or containers at a worksite.

Thank you for your interest in occupational safety and health. If we may be of further assistance, please contact us.


Roger A. Clark,
Directorate of Compliance Programs