- Safety and Health Topics
- Ammonia Refrigeration
This section highlights OSHA standards, preambles to final rules (background to final rules), directives (instruction to OSHA staff), official letters of interpretation (official letters of interpretation of the standards), and national consensus standards related to ammonia refrigeration.
This section also contains a partial list of good engineering practices which may also apply to many ammonia refrigeration facilities. This list is not intended to be all-inclusive or definitive, but should provide employers with a starting point for finding applicable codes, standards, and guidelines.
General Industry (29 CFR 1910)
- 1910.38, Emergency action plans [related topic page]
- 1910.119, Process safety management of highly hazardous chemicals. Applies to systems containing 10,000 lbs. of ammonia or greater. [related topic page]
- Appendix A, List of highly hazardous chemicals, toxics and reactives (Mandatory)
- Appendix B, Block flow diagram and simplified process flow diagram (Nonmandatory)
- Appendix C, Compliance guidelines and recommendations for process safety management (Nonmandatory)
- Appendix D, Sources of further information (Nonmandatory)
- 1910.120, Hazardous waste operations and emergency response. Generally, the emergency response requirements of 29 CFR 1910.120(q) apply to employers who use refrigeration systems utilizing anhydrous ammonia as a cooling agent. [related topic page]
- 1910.132, General requirements (Personal protective equipment) [related topic page]
- 1910.133, Eye and face protection [related topic page]
- 1910.134, Respiratory protection [related topic page]
- 1910.138, Hand protection
- 1910.307, Hazardous (classified) locations. There may be locations in an ammonia refrigeration system that are Class 1 Division 2 hazardous locations.
- 1910.1200, Hazard communication. Employers are required to communicate the hazards associated with working with ammonia to appropriate employees. [related topic page]
Preambles to Final Rules
- Process Safety Management of Highly Hazardous Chemicals -- Compliance Guidelines and Enforcement Procedures. CPL 02-02-045 (REVISED), (September 13, 1994).
Letters of Interpretation
- RAGAGEP in Process Safety Management Enforcement. (May 11, 2016).
- Memorandum to Regional Administrators - PSM Retail Exemption Policy. (July 22, 2015).
Note: OSHA is not implementing the July 2015 memo on the retail exemption. The Department is considering its options in light of the D.C. Circuits decision in Agricultural Retailers Association et al. v. United States Department of Labor and OSHA (D.C. Cir. Case Nos. 15-1326 and 15-1340).
- Process operators' training requirements to take limited action in stopping an emergency release; role in an incident command system. (February 14, 2004). Addresses questions about emergency response and the role of an incident commander.
- Process safety information for ventilation system design. (December 22, 2003). Clarifies documentation requirements for ventilation system design at certain facilities, including anhydrous ammonia terminals.
- Requirements for emergency response and planning under the Process Safety Management Standard. (June 24, 2003).
- Provisions of the Hazard Communication Standard. (June 20, 1997). Provides clarification of definitions under the Hazard Communication Standard (HCS) for units containing ammonia as a refrigerant.
- Process Safety Management of Highly Hazardous Chemicals and process hazard analyses. (October 31, 1996).
- Storage of flammable liquids and the applicability to the Process Safety Management standard. (September 11, 1995). Addresses the difference between required and elected actions under the Process Safety Management Standard with regard to storage of flammable liquids.
- Training for plant maintenance personnel and HAZWOPER. (January 26, 1993). Discusses how, in most instances, the emergency response provisions in 29 CFR 1910.120(q) apply to employers who use refrigeration systems utilizing anhydrous ammonia as a cooling agent.
- Various questions on OSHA standards. (September 1, 1992). Includes a discussion of how much training is required for employees working on refrigeration systems that contain ammonia.
- Fires involving spills or releases of hazardous substances. (June 17, 1991). Discusses the potential for ammonia refrigeration contractor's actions to fall under the scope of "emergency response" actions and the requirements of 29 CFR 1910.120(q).
- Ventilation for an anhydrous ammonia refrigeration system. (June 13, 1990). Addresses the issue of dilution ventilation and intrinsic safety in the mechanical control room for an anhydrous ammonia refrigeration system.
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.
American National Standards Institute (ANSI)/International Institute of Ammonia Refrigeration (IIAR)
- 1-2012, American National Standard for Definitions and Terminology Used in IIAR Standards. Provides a unified set of definitions for use in the IIAR Standards. A set of common definitions is provided to prevent confusion among engineers, contractors and jurisdictional authorities.
- 2-2014, American National Standard the Safe Design of Closed-Circuit Ammonia Refrigeration Systems. The new and improved IIAR 2 is the definitive design safety standard of the ammonia refrigeration industry.
- 3-2012, American National Standard for Ammonia Refrigeration Valves. Specifies criteria for materials, design parameters, marking and testing of valves and strainers used in closed circuit ammonia refrigeration systems.
- 4-2015, Installation of Closed-Circuit Ammonia Refrigeration Systems. Written to serve as a standard for the installation of closed-circuit ammonia mechanical refrigeration systems and overpressure protection relief piping systems.
- 5-2013, Start-up and Commissioning of Closed-Circuit Ammonia Refrigeration Systems. Provides basic minimum requirements for the safe start-up and commissioning of complete closed-circuit mechanical refrigerating systems utilizing ammonia as the refrigerant and additions and modifications made to such systems.
- 7-2013, Developing Operating Procedures for Closed-Circuit Ammonia Mechanical Refrigerating Systems. Defines the minimum requirements for developing operating procedures that are easy to understand, safe, effective, reliable, and meeting applicable regulatory environments.
- 8-2015, Decommissioning of Closed-Circuit Ammonia Refrigeration Systems. Specifies minimum criteria for removing the ammonia charge in conjunction with decommissioning of closed-circuit ammonia refrigeration systems.
American National Standards Institute (ANSI)/American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE)
- 15-2013 (Packaged w/ 34-2013), Safety Standard for Refrigeration Systems and Designation and Classification of Refrigerants (ANSI Approved). Standard 15 establishes procedures for design, construction, installation, inspection, testing, and operation of the equipment and systems using refrigerants. Standard 34 describes a shorthand way of naming refrigerants and assigns safety classifications based on toxicity and flammability data.
- 26-2010, Mechanical Refrigeration and Air-Conditioning Installations Aboard Ship. Provides recommendations and requirements for the safe and efficient design, construction, installation, operation, inspection, and maintenance of mechanical refrigerating and air-conditioning equipment aboard ships.
American Society of Heating Refrigerating and Air-conditioning Engineers (ASHRAE)
- ASHRAE Position Document on Ammonia as a Refrigerant. (February 1, 2017). Guidance with focus on preservation of the economic benefits of ammonia refrigeration while providing for the management of risks.
- 2014 Handbook - Refrigeration. Covers the refrigeration equipment and systems used for applications other than human comfort. Includes data and guidance on cooling, freezing, and storing food; industrial and medical applications of refrigeration; and low-temperature refrigeration. Primarily a reference for the practicing engineer, but also a useful reference for anyone involved in the cooling and storage of food products.
American National Standards Institute (ANSI)/American Society of Mechanical Engineers (ASME)
- B31.5-2013, Refrigeration Piping and Heat Transfer Components
- Boiler and Pressure Vessel Code, 2015 Edition. Establishes rules of safety relating only to pressure integrity, governing the design, fabrication and inspection of boilers and pressure vessels, and nuclear power plant components during construction.
American National Standards Institute (ANSI)/Compressed Gas Association (CGA)
- G-2.1 - 2014, American National Standard Safety Requirements for the Storage and Handling of Anhydrous Ammonia. Applies to the design, construction, repair, alteration, location, installation and operation of anhydrous ammonia systems including refrigerated ammonia storage systems. Sections on refrigerated storage systems, systems mounted on farm vehicles, tank motor vehicles, and tank railcars for transportation purposes are included. This standard does not apply to ammonia manufacturing plants, or refrigerating or air conditioning systems.