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.

January 23, 1995

[Name Withheld]

Dear [Name Withheld]:

This is in response to your December 24, 1994 letter, requesting interpretation of the Process Safety Management of Highly Hazardous Chemicals Standard, 29 CFR 1910.119.

In your letter, you have indicated that your client stores formalin (37%) in fifty five gallon drums, approximately one hundred yards from his mixing area, and only one to two drums are moved to the process area to make a product. Your specific questions and our responses follow.

Question 1: If 1000 pounds or more of formalin (37%) is present in the storage area, would my client fall under the Process Safety Standard?

Reply: Yes, in this case, your client would be covered by the Standard, 1910.119. Please note that a process is defined in 1910.119(b) as "any activity involving a highly hazardous chemical including any use, storage, manufacturing, handling, or the on-site movement of such chemicals, or combination of these activities. For purposes of this definition, any group of vessels which are interconnected and separate vessels which are located such that a highly hazardous chemical could be involved in a potential release shall be considered a single process".

Question 2: If the threshold limit of 1000 pounds was never reached in the storage or processing area, would this eliminate the need for implementation of the Process Safety Standard?

Reply: Paragraph (a)(1)(i) of 1910.119 clearly states that a process (as defined above) which involves a chemical at or above the specified threshold quantities listed in Appendix A of the Standard will be covered by this section. The threshold quantity listed in Appendix A for formalin is 1000 pounds, therefore, in order for this section to be applicable, the quantity of formalin must be 1000 or more pounds.

Thank you for your interest in occupational safety and health.


John B. Miles, Jr.
Director Directorate of Compliance Programs