Regulations last checked for updates: Nov 22, 2024

Title 40 - Protection of Environment last revised: Nov 20, 2024
Appendix Appendix W - Appendix W to Subpart G of Part 82—Substitutes Listed in the May 6, 2021 Final Rule—Effective June 7, 2021

Refrigerants—Substitutes Acceptable Subject to Narrowed Use Limits

End-use Substitute Decision Narrowed use limits Further information
Retail food refrigeration— medium-temperature stand-alone units (new only)R-448A, R-449A, R-449BAcceptable Subject to Narrowed Use LimitsAcceptable only for use in new medium-temperature stand-alone units where reasonable efforts have been made to ascertain that other alternatives are not technically feasible.
Users are required to document and retain the results of their technical investigation of alternatives for the purpose of demonstrating compliance.
A possible reason for rejection of one or more other alternative(s) could be based on ADA requirements.
Information shall include descriptions of:
• Process or product in which the substitute is needed;
• Substitutes examined and rejected;
• Reason for rejection of other alternatives, e.g., performance, technical or safety standards; and
• Anticipated date other substitutes will be available and projected time for switching.

Refrigerants—Substitutes Acceptable Subject to Use Conditions

End-use Substitute Decision Use conditions Further information
Residential and light commercial air conditioning and heat pumps (new only)R-452B, R-454A, R-454B, R-454C and R-457AAcceptable Subject to Use ConditionsThese refrigerants may be used only in new equipment specifically designed and clearly identified for the refrigerants (i.e., none of these substitutes may be used as a conversion or “retrofit” refrigerant for existing equipment designed for other refrigerants).
These substitutes may only be used in air conditioning equipment that meets all requirements in the 3rd edition of UL 60335-2-40. 1 2 3 In cases where this appendix includes requirements more stringent than those of UL 60335-2-40, the appliance must meet the requirements of this appendix in place of the requirements in the UL Standard.
The charge size for the equipment must not exceed the maximum refrigerant mass determined according to UL 60335-2-40 for the room size where the air conditioner is used.
Applicable OSHA requirements at 29 CFR part 1910 must be followed, including those at 29 CFR 1910.94 (ventilation) and 1910.106 (flammable and combustible liquids), 1910.110 (storage and handling of liquefied petroleum gases), and 1910.1000 (toxic and hazardous substances).
Proper ventilation should be maintained at all times during the manufacture and storage of equipment containing flammable refrigerants through adherence to good manufacturing practices as per 29 CFR 1910.106. If refrigerant levels in the air surrounding the equipment rise above one-fourth of the lower flammability limit, the space should be evacuated and reentry should occur only after the space has been properly ventilated.
The following markings must be attached at the locations provided and must be permanent:
(a) On the outside of the air conditioning equipment: “WARNING—Risk of Fire. Flammable Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant Tubing.”
(b) On the outside of the air conditioning equipment: “WARNING—Risk of Fire. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.”
(c) On the inside of the air conditioning equipment near the compressor: “WARNING—Risk of Fire. Flammable Refrigerant Used. Consult Repair Manual/Owner's Guide Before Attempting To Service This Product. All Safety Precautions Must be Followed.”
(d) For any equipment pre-charged at the factory, on the equipment packaging: “WARNING—Risk of Fire due to Flammable Refrigerant Used. Follow Handling Instructions Carefully in Compliance with National Regulations.”
(e) On the indoor unit near the nameplate:
a. At the top of the marking: “Minimum Installation height, X m (W ft)”. This marking is only required if required by UL 60335-2-40. The terms “X” and “W” shall be replaced by the numeric height as calculated per the UL Standard. Note that the formatting here is slightly different than the UL Standard; specifically, the height in Inch-Pound units is placed in parentheses and the word “and” has been replaced by the opening parenthesis.
b. Immediately below (a) above or at the top of the marking if (a) is not required: “Minimum room area (operating or storage), Y m 2 (Z ft 2)”. The terms “Y” and “Z” shall be replaced by the numeric area as calculated per the UL Standard. Note that the formatting here is slightly different than the UL Standard; specifically, the area in Inch-Pound units is placed in parentheses and the word “and” has been replaced by the opening parenthesis.
Technicians and equipment manufacturers should wear appropriate personal protective equipment, including chemical goggles and protective gloves, when handling flammable refrigerants. Special care should be taken to avoid contact with the skin which, like many refrigerants, can cause freeze burns on the skin.
A class B dry powder type fire extinguisher should be kept nearby.
Technicians should only use spark-proof tools when working on air conditioning equipment with flammable refrigerants.
Any recovery equipment used should be designed for flammable refrigerants. Only technicians specifically trained in handling flammable refrigerants should service refrigeration equipment containing these refrigerants. Technicians should gain an understanding of minimizing the risk of fire and the steps to use flammable refrigerants safely.
Room occupants should evacuate the space immediately following the accidental release of this refrigerant.
Personnel commissioning, maintaining, repairing, decommissioning and disposing of appliances with these refrigerants should obtain training and follow practices consistent with Annex HH of UL 60335-2-40, 3rd edition.1 2 3
CAA section 608(c)(2) prohibits knowingly venting or otherwise knowingly releasing or disposing of substitute refrigerants in the course of maintaining, servicing, repairing or disposing of an appliance or industrial process refrigeration.
Department of Transportation requirements for transport of flammable gases must be followed.
Flammable refrigerants being recovered or otherwise disposed of from residential and light commercial air conditioning appliances are likely to be hazardous waste under the Resource Conservation and Recovery Act (RCRA) (see 40 CFR parts 260-270).
(f) For non-fixed equipment, including portable air conditioners, window air conditioners, packaged terminal air conditioners and packaged terminal heat pumps, on the outside of the product: “WARNING—Risk of Fire or Explosion—Store in a well ventilated room without continuously operating flames or other potential ignition.”
(g) For fixed equipment, including rooftop units and split air conditioners, “WARNING—Risk of Fire—Auxiliary devices which may be ignition sources shall not be installed in the ductwork, other than auxiliary devices listed for use with the specific appliance. See instructions.”
(h) All of these markings must be in letters no less than 6.4 mm ( 1/4 inch) high.
The equipment must have red Pantone Matching System (PMS) #185 or RAL 3020 marked service ports, pipes, hoses, or other devices through which the refrigerant passes, to indicate the use of a flammable refrigerant. This color must be applied at all service ports and other parts of the system where service puncturing or other actions creating an opening from the refrigerant circuit to the atmosphere might be expected and must extend a minimum of one (1) inch (25mm) in both directions from such locations and shall be replaced if removed.
Residential and light commercial air conditioning and heat pumps (new only), excluding self-contained room air conditionersR-32Acceptable Subject to Use ConditionsThese refrigerants may be used only in new equipment specifically designed and clearly identified for the refrigerants (i.e., none of these substitutes may be used as a conversion or “retrofit” refrigerant for existing equipment designed for other refrigerants).
These substitutes may only be used in air conditioning equipment that meets all requirements in the 3rd edition of UL 60335-2-40.1 2 3 In cases where this appendix includes requirements more stringent than those of UL 60335-2-40, the appliance must meet the requirements of this appendix in place of the requirements in the UL Standard.
The charge size for the equipment must not exceed the maximum refrigerant mass determined according to UL 60335-2-40 for the room size where the air conditioner is used.
Applicable OSHA requirements at 29 CFR part 1910 must be followed, including those at 29 CFR 1910.94 (ventilation) and 1910.106 (flammable and combustible liquids), 1910.110 (storage and handling of liquefied petroleum gases), and 1910.1000 (toxic and hazardous substances).
Proper ventilation should be maintained at all times during the manufacture and storage of equipment containing flammable refrigerants through adherence to good manufacturing practices as per 29 CFR 1910.106. If refrigerant levels in the air surrounding the equipment rise above one-fourth of the lower flammability limit, the space should be evacuated and reentry should occur only after the space has been properly ventilated.
The following markings must be attached at the locations provided and must be permanent:
(a) On the outside of the air conditioning equipment: “WARNING—Risk of Fire. Flammable Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant Tubing.”
(b) On the outside of the air conditioning equipment: “WARNING—Risk of Fire. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.”
(c) On the inside of the air conditioning equipment near the compressor: “WARNING—Risk of Fire. Flammable Refrigerant Used. Consult Repair Manual/Owner's Guide Before Attempting To Service This Product. All Safety Precautions Must be Followed.”
(d) For any equipment pre-charged at the factory, on the equipment packaging: “WARNING—Risk of Fire due to Flammable Refrigerant Used. Follow Handling Instructions Carefully in Compliance with National Regulations”
(e) On the indoor unit near the nameplate:
a. At the top of the marking: “Minimum Installation height, X m (W ft)”. This marking is only required if required by UL 60335-2-40. The terms “X” and “W” shall be replaced by the numeric height as calculated per the UL Standard. Note that the formatting here is slightly different than the UL Standard; specifically, the height in Inch-Pound units is placed in parentheses and the word “and” has been replaced by the opening parenthesis.
b. Immediately below (a) above or at the top of the marking if (a) is not required: “Minimum room area (operating or storage), Y m 2 (Z ft 2)”. The terms “Y” and “Z” shall be replaced by the numeric area as calculated per the UL Standard. Note that the formatting here is slightly different than the UL Standard; specifically, the area in Inch-Pound units is placed in parentheses and the word “and” has been replaced by the opening parenthesis.
Technicians and equipment manufacturers should wear appropriate personal protective equipment, including chemical goggles and protective gloves, when handling flammable refrigerants. Special care should be taken to avoid contact with the skin which, like many refrigerants, can cause freeze burns on the skin.
A class B dry powder type fire extinguisher should be kept nearby.
Technicians should only use spark-proof tools when working on air conditioning equipment with flammable refrigerants.
Any recovery equipment used should be designed for flammable refrigerants. Only technicians specifically trained in handling flammable refrigerants should service refrigeration equipment containing this refrigerant. Technicians should gain an understanding of minimizing the risk of fire and the steps to use flammable refrigerants safely.
Room occupants should evacuate the space immediately following the accidental release of this refrigerant.
Personnel commissioning, maintaining, repairing, decommissioning and disposing of appliances with this refrigerant should obtain training and follow practices consistent with Annex HH of UL 60335-2-40, 3rd edition. 1 2 3
CAA section 608(c)(2) prohibits knowingly venting or otherwise knowingly releasing or disposing of substitute refrigerants in the course of maintaining, servicing, repairing or disposing of an appliance or industrial process refrigeration.
Department of Transportation requirements for transport of flammable gases must be followed.
Flammable refrigerants being recovered or otherwise disposed of from residential and light commercial air conditioning appliances are likely to be hazardous waste under the Resource Conservation and Recovery Act (RCRA) (see 40 CFR parts 260-270).
(f) For fixed equipment, including rooftop units and split air conditioners, “WARNING—Risk of Fire—Auxiliary devices which may be ignition sources shall not be installed in the ductwork, other than auxiliary devices listed for use with the specific appliance. See instructions.”
(g) All of these markings must be in letters no less than 6.4 mm ( 1/4 inch) high.
The equipment must have red Pantone Matching System (PMS) #185 or RAL 3020 marked service ports, pipes, hoses, or other devices through which the refrigerant passes, to indicate the use of a flammable refrigerant. This color must be applied at all service ports and other parts of the system where service puncturing or other actions creating an opening from the refrigerant circuit to the atmosphere might be expected and must extend a minimum of one (1) inch (25mm) in both directions from such locations and shall be replaced if removed.

1 UL 60335-2-40, Standard for Safety for Household And Similar Electrical Appliances—Safety—Part 2-40: Particular Requirements for Electrical Heat Pumps, Air-Conditioners and Dehumidifiers, Third edition, Dated November 1, 2019.

2 You may purchase the material from UL by mail: Comm 2000; 151 Eastern Avenue; Bensenville, IL 60106; email: [email protected]; phone: 1-888-853-3503 in the U.S. or Canada (other countries dial +1-415-352-2168); or web: www.shopulstandards.com.

3 The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. All approved material is available for inspection at U.S. EPA's Air and Radiation Docket; EPA West Building, Room 3334, 1301 Constitution Ave. NW, Washington, DC, 202-566-1742 and is available from Underwriters Laboratories Inc. (UL), 333 Pfingsten Road, Northbrook, IL 60062, 877.854.3577, www.ul.com. It is also available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

[86 FR 24471, May 6, 2021]
authority: 42 U.S.C. 7414,7601,7671
source: 57 FR 33787, July 30, 1992, unless otherwise noted.