OSHA PSM and EPA RMP for Ammonia Facilities Explained

OSHA Process Safety Management (PSM) and the EPA Risk Management Program (RMP) are two federal programs that apply to facilities holding more than a threshold quantity of certain hazardous chemicals. Anhydrous ammonia, the refrigerant in most large industrial refrigeration plants, is on both lists. PSM focuses on worker safety inside the facility. RMP focuses on preventing and responding to releases that could affect people and the environment outside the fence. Many ammonia facilities are covered by both and manage them together.

This article is a general overview, not legal advice. Thresholds, definitions and deadlines change, so always confirm them in the current regulation text.

What is OSHA PSM?

PSM is a standard in the Code of Federal Regulations at 29 CFR 1910.119. It applies to processes that involve listed highly hazardous chemicals at or above a stated threshold quantity, or certain flammable materials above a stated amount. Anhydrous ammonia is a listed chemical, and the threshold is based on the quantity in a process, not on the size of the building. Read the current standard and OSHA’s interpretation letters to see how “process” and “interconnected vessels” are counted for your plant.

PSM is a management-system standard. It does not tell you which valve to buy. It tells you to know your hazards, document your process, train your people and check your work.

What is the EPA RMP?

RMP comes from Section 112(r) of the Clean Air Act and is codified at 40 CFR Part 68. It applies to stationary sources holding more than a threshold quantity of a regulated substance in a process. Ammonia (anhydrous) is a regulated substance. Covered facilities submit a Risk Management Plan to EPA, update it on a schedule and implement a prevention program and an emergency response program.

RMP adds things PSM does not emphasize, such as an offsite consequence analysis, public-facing registration of the plan and coordination with local emergency planners.

Who is covered?

Coverage is quantity-based. The key questions are:

1. Is anhydrous ammonia (or another listed substance) present in a single process?
2. Does the total quantity in that process exceed the threshold in the current rule?
3. Is the facility a stationary source subject to the Clean Air Act provisions?

Many cold storage warehouses, food processors, dairies and beverage plants exceed the ammonia thresholds. Small ammonia systems may fall below them but are still subject to the OSHA General Duty Clause and the OSHA and fire code requirements that apply to any ammonia system.

What are the core elements of each program?

The two programs overlap heavily. This table gives a simplified comparison.

Topic	OSHA PSM	EPA RMP
Primary goal	Worker safety	Community and environment
Regulation	29 CFR 1910.119	40 CFR Part 68
Process safety information	Required	Required
Process hazard analysis (PHA)	Required, revalidated on a cycle	Required, revalidated on a cycle
Operating procedures	Required	Required
Training	Required, with refreshers	Required, with refreshers
Mechanical integrity	Required	Required
Management of change	Required	Required
Pre-startup review	Required	Required
Incident investigation	Required	Required
Compliance audits	Required on a cycle	Required on a cycle
Emergency planning	Emergency action plan, HAZWOPER where applicable	Emergency response program and coordination with local responders
Offsite consequence analysis	Not required	Required
Registration with a federal agency	No	Yes, Risk Management Plan submitted to EPA

How do PSM and RMP relate to each other?

They were written to complement each other, and EPA’s prevention program elements closely mirror OSHA’s. In practice a single set of documents, such as process safety information, PHAs, procedures, mechanical integrity records and audit reports, can support both programs. The differences are mainly in scope (inside versus outside the fence), the offsite consequence analysis and the registration and reporting requirements.

Industry standards from the International Institute of Ammonia Refrigeration (IIAR) are widely used to show recognized and generally accepted good engineering practice under both programs. See IIAR 2 and IIAR 6 standards explained.

What do the programs mean for day-to-day operations?

• Documented equipment data. Piping and instrument diagrams, relief valve sizing, ventilation design and electrical classification must be current and match the plant as built.
• Mechanical integrity program. Inspection and testing of vessels, piping, relief devices, controls and emergency systems follow written procedures and recognized practice, with records kept.
• Operator training. Operators are trained on the process and hazards, and their training is documented and refreshed.
• Management of change. Any change to equipment, chemicals, procedures or personnel responsibilities is reviewed before it is made.
• Contractor controls. Outside contractors must be selected and managed with safety performance in mind, and the facility must inform them of hazards.

For background on the systems themselves, read ammonia refrigeration system basics and ammonia vs freon refrigeration.

What is the status of EPA’s 2026 RMP proposal?

EPA has revised the RMP rule several times in recent years, and in 2026 it put forward proposed changes. Proposals can be modified, finalized, delayed or withdrawn, and compliance dates can shift. We do not summarize details here because they may be outdated by the time you read this. Check the current text on EPA’s RMP pages and the Federal Register, and ask your compliance advisor which version applies to your facility.

Frequently asked questions

Does a small ammonia system need to follow PSM?

Not necessarily. PSM applies when the quantity in a process meets or exceeds the threshold in the standard. A system below the threshold is not covered by PSM, but it is still expected to be designed, operated and maintained safely under general OSHA duties, local fire codes and industry standards.

Can one compliance program satisfy both PSM and RMP?

Largely yes. Many facilities build one process safety management system and add the RMP-specific items, such as the offsite consequence analysis, the emergency response coordination and the registration submittal. The facility must still confirm that each program’s specific requirements are met.

How often must a process hazard analysis be updated?

Both programs require periodic revalidation, commonly on a five-year cycle, and a new or updated analysis after certain changes. Confirm the exact interval and triggers in the current text of 29 CFR 1910.119 and 40 CFR Part 68.

SpecServis engineers in Ukraine work on industrial refrigeration plants, including ammonia systems. We are planning to enter the Central Texas market and are looking for technicians, partners and a company to buy. See our open positions or partnership options.

Sources

• OSHA Process Safety Management
• EPA Risk Management Program
• International Institute of Ammonia Refrigeration (IIAR)