PSM Applicability Checker
Answer a few questions to determine if OSHA PSM and EPA RMP apply to your facility. This is a preliminary assessment — consult a compliance professional for definitive determinations.
Does your facility have an ammonia refrigeration system?
This includes any mechanical refrigeration system using anhydrous ammonia (R-717) as the refrigerant.
The short answer
OSHA PSM and EPA RMP both apply to an ammonia refrigeration facility when the process contains 10,000 lb or more of anhydrous ammonia. The whole interconnected refrigeration system counts as one process. Coverage starts the day the threshold is met, with no grace period, and every one of the 14 PSM elements becomes citable at once.
The uncertain cases are the ones this checker is built for: an inventory that was estimated rather than calculated, a calculation that skipped piping, or a system that has grown since the number was last run. In those cases the next step is a formal inventory determination, not a guess in either direction.
Applicability questions
At what quantity does OSHA PSM apply to ammonia?
OSHA PSM applies when a process contains 10,000 pounds or more of anhydrous ammonia (29 CFR 1910.119, Appendix A). EPA's Risk Management Program uses the same 10,000 lb threshold quantity under 40 CFR 68.130. For a refrigeration system the whole interconnected system is normally one process, so the threshold is compared against the total charge, not any single vessel.
Does the threshold apply to the nameplate charge or the actual charge?
Neither by itself. OSHA and EPA look at the maximum quantity the process can contain at any time, which is why a documented maximum intended inventory matters. A nameplate or design charge is a starting point, but systems are topped off, expanded, and run at different conditions over their life.
Is a facility with 9,500 lb of ammonia off the hook?
It is not covered by PSM or RMP, but it still owes a defensible inventory calculation, and it is exposed to OSHA's General Duty Clause and EPA's general duty requirement under CAA 112(r)(1), both of which expect conformance with IIAR standards. A facility that close to the threshold should also expect the number to move with season, level setpoints, and any added equipment.
Is this checker a formal determination?
No. It sorts facilities into clearly covered, clearly not covered, and uncertain, and tells you what to do next in each case. A formal determination is a component-level inventory calculation prepared and documented by a qualified person.
Related tools
If the answer was uncertain, these are the next things to check.
Pounds of ammonia in a single receiver, accumulator, or intercooler.
OpenWhat counts, what does not, and where calculations go wrong.
OpenIf you are covered: when the next PHA, audit, and RMP are due.
OpenWhat a complete program has to contain.
OpenOperating an ammonia refrigeration facility?
NH3Edge provides OSHA PSM and EPA RMP compliance consulting for ammonia refrigeration facilities — third-party compliance audits, ammonia inventory determination, and continuous real-time inventory monitoring. Based in Salt Lake City, serving facilities nationwide.