Steps for updating and revalidating a Process Hazard Analysis (PHA).

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 22, 1998

Mr. Baruch A. Fellner
Gibson, Dunn & Crutcher, LLP
1050 Connecticut Avenue, N.W.
Washington, DC 20036-5306

Dear Mr. Fellner:

The following response is in reference to your letter dated April 7, 1997, to me, related to employer requirements under OSHA's (Process Safety Management of Highly Hazardous Chemicals, Explosives and Blasting Agents [PSM]) standard for updating and revalidating process hazard analyses [PHA](29 CFR 1910.119(e)(6)). We apologize for the delay in our response.

Documentation methods used to comply with the qualitative evaluation of a range of possible safety/health effects of "failure of controls" requirement of the PSM standard.

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, 2005

Mr. Roygene Harmon
Industrial Consultants
10470 W. Devils Den Road
Winslow, AR 72959

Dear Mr. Harmon:

PSM compliance for ammonia refrigeration 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.

***Response 10 updated July 07, 2015***

July 12, 2006

Mr. E. C. Palmer, Jr.
Environmental Attorney/Consultant
LAMB GROUP, LLC.
330 Providence Road
Athens, GA 30606

Dear Mr. Palmer: