Compliance with PSM and ANSI/ISA-S84.01 for safety instrumented systems

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.

March 23, 2000

Ms. Lois M. Ferson
Manager of Standards Services
ISA
67 Alexandria Drive
P.O. Box 12277
Research Triangle Park, NC 27709

Dear Ms. Ferson:

"Applicability of the PSM standard's mechanical intergrity requirements to refinery structures."

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.

February 1, 2010

The Honorable David Vitter
United States Senate
Washington, DC 20510

Dear Senator Vitter: