Ammonia Refrigeration


Ammonia refrigeration is addressed in OSHA standards for general industry. This section highlights OSHA standards and documents related to ammonia refrigeration.

OSHA Standards
General Industry (29 CFR 1910)
General Industry (29 CFR 1910)
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1910 Subpart E - Exit Routes and Emergency Planning

1910.38, Emergency action plans.

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1910 Subpart H - Hazardous Materials

1910.119, Process safety management of highly hazardous chemicals. * Applies to systems containing 10,000 lbs. of ammonia or greater.

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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.

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1910 Subpart I - Personal Protective Equipment

1910.132, General requirements.

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1910.133, Eye and face protection.

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1910.134, Respiratory protection.

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1910.138, Hand Protection.

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1910 Subpart S - Electrical

1910.307, Hazardous (classified) locations. There may be locations in ammonia refrigeration systems that are Class 1 Division 2 hazardous locations.

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1910 Subpart Z - Toxic and Hazardous Substances

1910.1000, Air contaminants.

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1910.1200, Hazard Communication. Employers are required to communicate the hazards associated with working with ammonia to appropriate employees.

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State Plan Standards

There are 29 OSHA-approved State Plans operating state-wide occupational safety and health programs. State Plans are required to have standards and enforcement programs that are at least as effective as OSHA's and may have different or more stringent requirements.

National Consensus Standards

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)

  • ANSI/IIAR 1, 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.
  • ANSI/IIAR 2, American National Standard for 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.
  • ANSI/IIAR 3, 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.
  • ANSI/IIAR 4, 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.
  • ANSI/IIAR 5, 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.
  • ANSI/IIAR 7, 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.
  • ANSI/IIAR 8, 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)

  • ANSI/ASHRAE Standard 15 and 34, Standard 15 - Safety Standard for Refrigeration Systems and ANSI/ASHRAE Standard 34 - Designation and Safety Classification of Refrigerants. ANSI/ASHRAE Standard 15 must be used with its sister standard ANSI/ASHRAE Standard 34. 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.
  • ANSI/ASHRAE Standard 26, 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. Guidance with focus on preservation of the economic benefits of ammonia refrigeration while providing for the management of risks.
  • ASHRAE 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, Refrigeration Piping and Heat Transfer Components
  • Boiler and Pressure Vessel Code. 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, 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.