Storage Tank Regulations

Are atmospheric storage tanks to be included in PSM and require PHA?

Updated 26 December 2022

Clarification to the current Process Safety Management standard CFR 1910.119 looks to be finally getting the review that industry has needed since the PSM standard was introduced in the early nineties.

Currently, the type of connection between a storage tank containing flammables and or other hazardous commodities, can be the deciding factor as to whether connected components are truly excluded from the covered process and PSM.

For instance, an atmospheric storage tank attached only temporarily by a rubber hose to an intermediate vessel within a covered process is often considered as excluded from the covered process and PSM. Similarly, an atmospheric storage tank with an outlet connection used to fill drums that will subsequently be used for filling an intermediate vessel within a covered process, may also be excluded from the covered process and PSM.

The existing PSM standard applies in part to processes involving a flammable liquid or gas on site in one location in a quantity of 10,000 pounds or more. However, the existing PSM standard contains an exemption for

“[f]lammable liquids stored in atmospheric tanks or transferred which are kept below their normal boiling point without benefit of chilling or refrigeration.” 29 CFR §1910.119 (a)(1)(ii)(B).

OSHA is considering clarifying this exemption in response to a decision by an Administrative Law Judge of the Occupational Safety and Health Review Commission. In Secretary of Labor v. Meer Corporation, No. 95-0341 (OSHRC 1997), an administrative law judge ruled that PSM coverage does not extend to flammables stored in atmospheric tanks, even if the tanks are connected to a process. As a result, employers can exclude the amount of flammable liquid contained in an atmospheric storage tank, or in transfer to or from storage, from the quantity contained in the process when determining whether a process meets the 10,000-pound threshold quantity. On May 12, 1997, OSHA issued a Regional Administrator’s memorandum acknowledging this decision (OSHA, 1997). The Meer decision was contrary to OSHA's earlier interpretation of subsection (a)(1)(ii)(B), which was that the standard covered all stored flammables when connected to or located in close proximity to a process. The Meer decision was relevant in the Motiva refinery explosion and fire in Delaware City, DE, in 2001, and in an explosion at National Vinegar Company in Houston, TX in 1997. (, 10 May 2016)

Finally, the above excerpt from OSHA in 1997, will be clarified because of future evaluation by industry representatives and experts through a public meeting sponsored by OSHA. The meeting is scheduled to be held on    TBD    .


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