Ammonia refrigeration regulations: OSHA PSM, EPA RMP & IIAR standards
Three regulatory frameworks — OSHA PSM, EPA RMP, and IIAR standards — define the compliance landscape for ammonia refrigeration facilities. Here's what each requires and how they interact.
Ammonia refrigeration is regulated by two federal agencies working from the same trigger. OSHA regulates ammonia under its Process Safety Management standard, 29 CFR 1910.119, which protects workers inside the facility. EPA regulates the same systems under the Risk Management Program, 40 CFR Part 68, which protects the public and environment outside the fence line. Both apply when a process contains 10,000 pounds or more of anhydrous ammonia — and for a refrigeration system, the entire interconnected system usually counts as one process.
Neither regulation tells you how to build a safe ammonia system. For the engineering details, both agencies defer to the IIAR standards as RAGAGEP — Recognized and Generally Accepted Good Engineering Practice. In practice this means an OSHA inspector evaluates your engine room against ANSI/IIAR 2, IIAR 6, and IIAR 9, and your compliance audit should do the same. Facilities below 10,000 lb are not off the hook either: the OSHA and EPA General Duty Clauses reference the same standards at any ammonia quantity.
Everything starts with one number — your actual ammonia inventory. If you don't have a documented, component-level inventory determination, your coverage status is a guess. The reference below summarizes what each framework requires and how they compare.
Does your facility exceed the 10,000 lb threshold?
OSHA PSM and EPA RMP do not apply. IIAR safety standards still apply as best practice. Good time to get a formal inventory determination.
You may cross the threshold under certain operating conditions. Continuous monitoring and a current component-level inventory calculation are strongly recommended.
OSHA PSM (29 CFR 1910.119) and EPA RMP Program 3 (40 CFR Part 68) both apply. Full compliance required immediately.
OSHA PSM vs. EPA RMP: Side-by-Side Comparison
Both programs apply to ammonia at 10,000 lb. They overlap substantially but have distinct requirements.
| Requirement | OSHA PSM | EPA RMP |
|---|---|---|
| Threshold | 10,000 lb NH₃ | 10,000 lb NH₃ |
| Citation | 29 CFR 1910.119 | 40 CFR Part 68 |
| Regulator | OSHA (DOL) | EPA |
| Process Hazard Analysis | Required (Element 3) | Required (Prevention Program) |
| Emergency Response Plan | Required (Element 12) | Required (with local coordination) |
| Compliance Audits | Every 3 years | Facility audits (CCCAP: third-party) |
| Incident Investigation | Required (Element 11) | Required (root cause under CCCAP) |
| Operating Procedures | Required (Element 4) | Written procedures required |
| Training | Required (Element 5) | Training required |
| Management of Change | Required (Element 10) | Required |
| Mechanical Integrity | Required (Element 8) | Required |
| Hazard Assessment | PHA | Worst-case + alternative scenarios |
| Public Reporting | Not required | RMP submission (public record) |
| Penalty for Non-Compliance | Up to $15,625/violation/day | Up to $70,117/day |
| Public Meeting Requirement | No | Yes (CCCAP 2024) |
| Third-Party Audit | No (internal OK) | Yes (CCCAP 2024, every 3 years) |
IIAR Standards: The Technical Foundation
OSHA and EPA both rely on IIAR standards as RAGAGEP (Recognized and Generally Accepted Good Engineering Practice) for ammonia refrigeration.
Safe Design of Closed-Circuit Ammonia Refrigerating Systems
Design requirements for new ammonia refrigeration systems. Includes refrigerant piping design, PRV sizing for new systems, component specifications, system safety requirements. Used as design RAGAGEP for PSI documentation.
Minimum System Safety Requirements for Existing Closed-Circuit Ammonia Refrigeration Systems
Safety requirements for existing (pre-IIAR 2 2014) ammonia refrigeration systems. Provides a compliance pathway for older systems including PRV requirements, inspection requirements, and documentation standards.
Guidelines for Start-Up, Inspection, and Maintenance
The primary RAGAGEP for Mechanical Integrity programs under OSHA PSM Element 8. Specifies inspection types, frequency, documentation requirements, and maintenance procedures for all major system components.
Inspection, Testing, and Maintenance of Closed-Circuit Ammonia Refrigerating Systems
Detailed inspection and maintenance requirements. Complements Bulletin 110 with more specific guidance on inspection intervals, test procedures, and acceptance criteria for ammonia system components.
Official Regulatory Resources
Full text of 29 CFR 1910.119 on the OSHA website
Full text of EPA Risk Management Program rule
Purchase IIAR standards and technical guidance documents
EPA portal for Risk Management Plan submission
OSHA PSM enforcement guidance and inspection procedures
2024 amendments to the EPA Risk Management Program
Ammonia regulation questions
What are the OSHA regulations for ammonia refrigeration?
The primary OSHA regulation is the Process Safety Management standard, 29 CFR 1910.119, which applies to any process containing 10,000 lb or more of anhydrous ammonia and requires a 14-element safety program. Below that threshold, the OSH Act General Duty Clause still requires facilities to address recognized hazards — and OSHA looks to IIAR standards to define what a safe ammonia system looks like. General standards for emergency response (1910.120), respiratory protection (1910.134), and permissible exposure limits also apply.
What EPA regulations apply to ammonia refrigeration?
The EPA Risk Management Program rule, 40 CFR Part 68, applies at the same 10,000 lb threshold and requires a Risk Management Plan filed with EPA, hazard assessment with worst-case release modeling, and a prevention program that largely mirrors OSHA PSM. Below the threshold, EPA's General Duty Clause under Clean Air Act §112(r)(1) still applies. Ammonia releases of 100 lb or more in 24 hours are also reportable under CERCLA and EPCRA.
At what amount of ammonia do PSM and RMP apply?
Both programs trigger at 10,000 lb of anhydrous ammonia in a process. For refrigeration systems, the entire interconnected system typically counts as one process — vessels, heat exchangers, and piping together. Because the true system charge is rarely obvious, facilities near the threshold need a formal component-level inventory determination.
What are IIAR standards and are they legally required?
IIAR standards (ANSI/IIAR 2, 4, 5, 6, 7, 8, and 9) are industry consensus standards for ammonia refrigeration design, installation, operation, and maintenance. They are not regulations themselves, but OSHA and EPA treat them as RAGAGEP — Recognized and Generally Accepted Good Engineering Practice — which means inspectors measure your facility against them. Practically, conformance with IIAR standards is how a facility demonstrates compliance with the engineering requirements of PSM and RMP.
We implement these regulations for a living
Compliance Audits
14-element OSHA PSM audit, EPA RMP review, and RAGAGEP conformance against IIAR standards.
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Program development, PHA facilitation, and mechanical integrity across all 14 elements of 1910.119.
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Hazard assessment, offsite consequence analysis, and five-year resubmissions under 40 CFR Part 68.
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