Ammonia Refrigeration Rules

Below is our attempt at describing laws, regulations, codes, industry standards, and so forth (collectively "rules") applicable to ammonia refrigeration, along with their publication history. There may be some date and name errors, especially for older editions. This information is:
Provided for free, as is. Use at your own risk. Absolutely no warranty.

Change Log:
2024-08-12 -- Updated IIAR 9 entry for its 2024 Addendum A.
2023-02-27 -- Updated edition years for IIAR 1-2022.
2022-09-28 -- Added ASCE 7 entry and updated IMC, IFC, and NFPA 1 entries.
2022-09-23 -- Updated 527 CMR 1, ASME PCC-2, and IIAR 3 entries for new editions.
2022-07-11 -- Updated API 579-1/ASME FFS-1 entry for 2021 edition, actually published in 2022.
2021-09-17 -- Updated IIAR 2 and Bulletin 114 entries and noted that the Bulletins are all superseded.
2020-12-21 -- Updated IIAR 4 and IIAR 8 entries.
2020-10-21 -- Added NBIC and SPS 341 entries. Updated SPS 345 entry.
2020-09-11 -- Added ASME PCC-2, Repair of Pressure Equipment and Piping.
2020-09-04 -- Added API 579-1/ASME FFS-1, Fitness-For-Service, and note about them in IIAR 6 entry.
2020-08-14 to 2020-08-11 -- Added general duty and Massachusetts Comprehensive Fire Safety Code. Updated EPA CAP/RMP rule publication history. Corrected superseded IIAR Bulletin 110 record to show first publication in March 1993. Updated ASME code publication dates. Added headings.
2020-03-19 -- Updated for publication of IIAR 9.
2019-11-14 -- Updated IIAR Bulletins status. Bulletin 114 has 2019 edition and is only bulletin not superseded by an IIAR standard. Proposed IIAR 9 name updated. Added note to ASHRAE 15 that IIAR 2 now comprehensive for ammonia refrigeration. Added IFC and NFPA 1 entries.
2019-08-06 -- IIAR 2 updated for 2014 Addendum A, published in July 2019.
2019-06-03 -- IIAR 7 updated for new edition. Added note on state and local building codes.
2019-05-20 -- IIAR 6 updated for first edition.
2017-12-18 -- Added entry for Wisconsin Commercial Building Code. Updated entries for SPS 345 (website URL changed), IMC, ASME Boiler and Pressure Vessel Code, ASME B31.5, IIAR 2, proposed IIAR 6, IIAR 7, and proposed IIAR 9.
2017-11-03 -- Updated edition years for IIAR 1, IIAR 3, and IIAR Bulletin 114, updated status of IIAR 6 and IIAR 9, and clarified that IIAR Bulletins 107, 111, and 112 have been superseded by IIAR standards.
2017-01-26 -- Added entry for proposed IIAR 9. Updated entries for ASME B31.5, IIAR 2, IIAR 6 (proposed), and IIAR Bulletins.

Laws and U.S. federal regulations

General duty -- This may include:
(1) the duty of care that comes with owning or operating an ammonia-refrigeration system, to avoid negligence under tort law in the jurisdiction where the ammonia-refrigeration system is located and
in the USA, the following general-duty laws
(2) Occupational Safety and Health Act of 1970 Section 5, 29 U.S. Code 654, and
(3) Clean Air Act paragraph 112(r)(1), 42 U.S. Code 7412(r)(1), promulgated by the Clean Air Act Amendments of 1990.

29 CFR 1910.119 -- Title 29, Code of Federal Regulations (CFR), Section 1910.119. This is the Process Safety Management (PSM) rule administered by the U.S. Department of Labor, Occupational Safety and Health Administration (OSHA). Federal Register (FR) publication and amendments: 57 FR 6403, February 24, 1992; 57 FR 7847, March 4, 1992; 61 FR 9238, March 7, 1996; 67 FR 67964, November 7, 2002; 76 FR 80738, December 27, 2011; 77 FR 17776, March 26, 2012; 78 FR 9313, February 8, 2013. Available from https://gpo.gov or https://osha.gov

40 CFR 68 -- Title 40, Code of Federal Regulations, Part 68. This is the Chemical Accident Prevention (CAP) rule administered by the U.S. Environmental Protection Agency (EPA), which sometimes requires submission of a Risk Management Plan (RMP). Federal Register (FR) publication and amendments: 59 FR 4493, January 31, 1994. Redesignated at 61 FR 31717, June 20, 1996; 61 FR 31729, June 20, 1996; as amended at 62 FR 45132, August 25, 1997; 63 FR 645, January 6, 1998; 64 FR 980, January 6, 1999; 64 FR 28700, May 26, 1999; 65 FR 13250, March 13, 2000; 69 FR 18832, April 9, 2004; 82 FR 4594-4705, January 13, 2017; 84 FR 69843-69916 December 19, 2019. Available from https://gpo.gov or https://epa.gov

State, provincial, and local codes

Check for building (new and existing), electrical, energy, fire, fuel gas, hazardous substance, mechanical, plumbing, and zoning codes and other applicable rules in the jurisdiction where the facility is located. A few examples are listed below.

527 CMR 1.00:60.8 -- Massachusetts Comprehensive Fire Safety Code, Title 527, Code of Massachusetts Regulations (CMR), Part 1.00, Chapter 60 Hazardous Materials, section 60.8 Hazardous Material Process or Processing. Formerly numbered 527 CMR 33. Has five [5] categories of process based on volume or weight: up to and including [1] 2.5, [2] 60, or [3] 300 gallons of hazardous substance, such as anhydrous ammonia, [4] over 300 gallons but not category [5], and [5] holds at least the threshold quantities at 29 CFR 1910.119 or 40 CFR 68; see above. Applies to refrigeration systems that use ammonia, propane, or other liquefied petroleum gases (LPG). Adopts, with modifications, NFPA 1. For the latest version and a revision history, showing when various editions of NFPA 1 were adopted, see https://www.mass.gov/service-details/massachusetts-fire-code

Wisconsin Commercial Building Code -- Chapter SPS 361 to 365, Wisconsin Administrative Code. This adopts the International Mechanical Code and other International Code Council codes, with some exceptions for ammonia refrigeration in industrial occupancies. Available from the Legislative Reference Bureau https://legis.wisconsin.gov/lrb/

SPS 341 -- Chapter SPS 341, Boilers and Pressure Vessels, Wisconsin Administrative Code. Only Subchapter VI -- Repairs and Alterations, applies to pressure vessels in mechanical refrigeration systems. SPS 341 adopts the National Board Inspection Code. Guidance and information on any updates are available at https://dsps.wi.gov. The current and older editions may be obtained by contacting the Legislative Reference Bureau https://legis.wisconsin.gov/lrb/

SPS 345 (formerly Comm 45, ILHR 45, and Ind 45) -- Chapter SPS 345, Mechanical Refrigeration, Wisconsin Administrative Code. This code is administered by the Division of Industry Services (formerly Safety and Buildings), Department of Safety and Professional Services (formerly Commerce). This code has a long history, for example, a revised edition of Ind 45 was published in March 1963. In September 1983 it was revised and renamed ILHR 45, and subsequently revised effective: September 1, 1994; November 1, 1996 (and renamed Comm 45); July 1, 2002; November 1, 2003 (which adopted the increased relief-vent (RV) pipes sizes in ASHRAE Addendum 15c-2000); September 1, 2010; January 1, 2012 (only renamed SPS 345); June 1, 2012; and October 1, 2013. Since September 1, 2010, this code has referenced ASHRAE 15-2007 (including addenda a to i) and IIAR 2-2008, which in turn reference the ASME codes described below. Guidance and information on any updates are available at https://dsps.wi.gov. The current and older editions of SPS 345, Comm 45, ILHR 45, and Ind 45 may be obtained by contacting the Legislative Reference Bureau https://legis.wisconsin.gov/lrb/

Model building codes, industry standards, and so forth

IMC -- International Mechanical Code (IMC). Regarding ammonia refrigeration, the IMC has typically referenced and been mostly consistent with ASHRAE 15 and IIAR 2, with additional requirements in some editions. The IMC has been published every three years since 2000. IMC 2000 was adopted, in part, by Comm 45, Wisconsin Administrative Code, from November 1, 2003, to August 31, 2010. The IMC may be purchased from the International Code Council at https://www.iccsafe.org

IFC -- International Fire Code (IFC). The IFC references IIAR standards and includes additional requirements that may apply to ammonia-refrigeration systems, in some editions. The IFC may be purchased from the International Code Council at https://www.iccsafe.org

NFPA 1 -- National Fire Protection Association (NFPA) 1. NFPA 1 references IIAR standards and includes additional requirements that may apply to ammonia-refrigeration systems, in some editions. NFPA 1 may be purchased at https://nfpa.org

ASCE 7 -- Minimum Design Loads and Associated Criteria for Buildings and Other Structures, published by the American Society of Civil Engineers and its Structural Engineering Institute (ASCE/SEI). Updated periodically and referenced by many building codes and ASME B31.5. ASCE 7 may be purchased at https://asce.org. The ASCE 7 Hazard Tool is currently free, at https://asce7hazardtool.online

ASHRAE 15 -- American National Standards Institute (ANSI)/American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE), Standard 15, "Safety Standard for Mechanical Refrigeration." Since publication of the 2019 Addendum A to IIAR 2, building codes have started allowing ammonia-refrigeration systems to only follow IIAR 2, for design, without needing to also follow ASHRAE 15. ASHRAE 15 has been published every 3 years since 2001, with more frequent addenda (https://ashrae.org/standards-research--technology/standards-addenda) and interpretations (https://ashrae.org/standards-research--technology/standards-interpretations). The forward of the 2013 edition indicates, "The first Safety Code for Mechanical Refrigeration, recognized as American Standard B9 in October 1930, appeared in the first edition, 1932-1933, of the ASRE Refrigerating Handbook and Catalog. ASRE revisions designated ASA B9 appeared in 1933 and 1939. ASRE revisions designated ASA B9.1 appeared in 1950, 1953, and 1958. After the formation of ASHRAE, editions appeared as ASA B9.1-1964, ANSI B9.1-1971, ANSI/ASHRAE 15-1978, ANSI/ASHRAE 15-1989, ANSI/ASHRAE 15-1992, ANSI/ASHRAE 15-1994, ANSI/ASHRAE 15-2001, ANSI/ASHRAE 15-2004, ANSI/ASHRAE 15-2007, and ANSI/ASHRAE 15-2010." ASHRAE publications may be purchased from https://ashrae.org

ASME Boiler and Pressure Vessel Code -- the American Society of Mechanical Engineers (ASME) has published this code since 1914. Recent editions include 2010, 2013, 2015, 2017, 2019 and publication planned every two years going forward, possibly with more recent interpretations or code cases. ASME publications may be purchased from https://www.asme.org

ASME B31.5, Refrigeration Piping and Heat Transfer Components -- This code was separated from the power-piping code (B31.1) in 1962, and revised in 1966, 1974, 1978, 1983, 1987, 1989, 1992, 2001, 2006, 2010, 2013, 2016, 2019, and publication planned every three years going forward, possibly with more frequent addenda and interpretations. ASME B31.5 covers materials, design, fabrication, assembly, erection, testing, and inspection. ASME publications may be purchased from https://www.asme.org

API 579-1/ASME FFS-1, Fitness-For-Service -- This standard developed from an American Petroleum Institute (API) recommended practice published in 2000, and it was first published as a joint API/ASME standard in 2007. Revised editions were published in 2016 and 2021. ASME publications may be purchased from https://www.asme.org

ASME PCC-2, Repair of Pressure Equipment and Piping -- This standard covers temporary repair options, such as Article 3.6, Mechanical Clamp Repair, as well as long-term repair options, whose costs may be compared to replacement. The following editions have been published: 2006, 2008, 2011, 2015, 2018, and 2022. ASME publications may be purchased from https://www.asme.org

NBIC, National Board Inspection Code -- The NBIC provides standards for installation, inspection, repairs, and alternations of boilers, pressure vessels, and pressure-relief devices. It was first published in 1946. New editions are published in July of odd numbered years. Applicability of the NBIC to ammonia mechanical refrigeration systems varies by jurisdiction. The NBIC may be purchased from https://www.nationalboard.org

IIAR 1 -- ANSI/International Institute of Ammonia Refrigeration (IIAR), Standard 1, "Definitions and Terminology Used in IIAR Standards." The first edition was published in 2012. Revised editions were published in 2017 and 2022. IIAR publications may be purchased from https://iiar.org

IIAR 2 -- ANSI/IIAR, Standard 2, "Design of Safe Closed-Circuit Ammonia Refrigeration Systems". The first edition was published in March 1974 as IIAR 74-2. Revised editions (or addenda) were published in 1984, December 1992, August 1999, October 2005, June 2008, August 2010, December 2012, November 2015 (named the 2014 edition), July 2019 (named 2014 Addendum A), and about September 10, 2021. This standard was named "Equipment, Design, and Installation of Closed Circuit Ammonia Mechanical Refrigerating Systems" prior to the 2014 edition. For the editions published from 2014 to 2019 it was named "Safe Design of Closed-Circuit Ammonia Refrigeration Systems".

IIAR 3 -- ANSI/IIAR, Standard 3, "Ammonia Refrigeration Valves". IIAR 3-2005 was an Informative Reference of IIAR 2-2008 and IIAR 3-2017 was an Informative Reference of IIAR 2-2021. The first edition was published in 2005. Revised editions were published in 2012, 2017, and 2022.

IIAR 4 -- ANSI/IIAR, Standard 4, "Installation of Closed-Circuit Ammonia Refrigeration Systems". The first edition was published in 2015. A revised edition was published in 2020.

IIAR 5 -- ANSI/IIAR, Standard 5, "Start-up and Commissioning of Closed-Circuit Ammonia Refrigeration Systems". The first edition was published in 2013. A revised edition was published in 2019.

IIAR 6 -- ANSI/IIAR, Standard 6, "Inspection, Testing, and Maintenance of Closed-Circuit Ammonia Refrigeration Systems". The first edition was published in May 2019. Do not use the fitness-for-service information in IIAR 6-2019, Chapters 10 and 11, for example, when assessing corroded or damaged vessels or piping, without also consulting the latest edition of API 579-1/ASME FFS-1, Fitness-For-Service, because the simplified methods in IIAR 6-2019 do not reproduce the limitations of the API 579-1/ASME FFS-1 methods, for example, corrosion or damage near nozzles, supports, cracks, grooves, gouges, welds, or other areas that may experience additional stress.

IIAR 7 -- ANSI/IIAR, Standard 7, "Developing Operating Procedures for Closed-Circuit Ammonia Mechanical Refrigerating Systems". The first edition was published in 2013. A revised edition was published in 2019.

IIAR 8 -- ANSI/IIAR, Standard 8, "Decommissioning of Closed-Circuit Ammonia Refrigeration Systems". The first edition was published in 2015. A revised edition was published in 2020.

IIAR 9 -- ANSI/IIAR, Standard 9, "Minimum System Safety Requirements for Existing Closed-Circuit Ammonia Refrigeration Systems". The first edition was published in March 2020. Addendum A was published in August 2024.

IIAR Bulletins -- These provided recommendations that were meant to be voluntary and non-binding, but which may become "good engineering practice" and therefore required under PSM and CAP regulations, if they are widely followed. By September 2021, they were all superseded by IIAR standards. A partial list is below.
IIAR Bulletin 107 (1997, superseded by IIAR 5-2013, IIAR 4-2015, and subsequent editions), "Guidelines for: Suggested Safety and Operating Procedures When Making Ammonia Refrigeration Plant Tie-ins."
IIAR Bulletin 108 (1986, superseded by IIAR 6-2019), "Guidelines for: Water Contamination in Ammonia Refrigeration Systems." Includes water-content test method.
IIAR Bulletin 109 (1997, superseded by IIAR 6-2019 and IIAR 9-2020), "Guidelines for: IIAR Minimum Safety Criteria for a Safe Ammonia Refrigeration System.".
IIAR Bulletin 110 (March 1993; revised March 2002, February 4, 2004, and May 24, 2007; superseded by IIAR 5-2013, IIAR 4-2015, IIAR 6-2019, and subsequent editions of these IIAR standards), "Guidelines for: Start-up, Inspection and Maintenance of Ammonia Mechanical Refrigerating Systems." Section 6.0 - Inspection and Maintenance contains information on mechanical integrity. Section 6.4 was revised in February 4, 2004. Section 6.6.3 was revised in May 24, 2007.
IIAR Bulletin 111 (2002, superseded by IIAR 2), "Guidelines for: Ammonia Machinery Room Ventilation." Superseded by the ventilation requirements in the 2010 Addendum A of IIAR 2-2008 and subsequent editions. But, provides diagrams of suggested air flow that are not in these standards.
IIAR Bulletin 112 (1998, superseded by IIAR 2), "Guidelines for: Ammonia Machinery Room Design." Superseded by the 2010 Addendum A of IIAR 2-2008 and subsequent editions.
IIAR Bulletin 114 (1991, revised in 2014, 2017, and 2019, superseded by IIAR 2-2021, which included this document as informative Appendix Q), "Guidelines for Identification of Ammonia Refrigeration Piping and System Components."
IIAR Bulletin 116 (1992, superseded by IIAR 6-2019), "Guidelines for: Avoiding Component Failure in Industrial Refrigeration Systems Caused by Abnormal Pressure or Shock."

IIAR updates and interpretations are available at the IIAR website https://iiar.org, under the "Technology and Standards" menu select "Standards Review" and then select "ANSI/IIAR Standards Interpretations". For the latest editions, under the "Store" menu select "Bulletins" or "Standards".

We place no restriction on the use, modification, or redistribution of the information above.

Originally Posted: 2015-04-30
Last Modified: 2024-08-12
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