Appendix R to Subpart G of Part 82 - —Substitutes Subject to Use Restrictions Listed in the December 20, 2011, Final Rule, Effective February 21, 2012, in the April 10, 2015, Final Rule, Effective May 11, 2015, in the April 28, 2023, Final Rule, Effective May 30, 2023, and in the June 13, 2024, Final Rule, Effective July 15, 2024

Appendix R to Subpart G of Part 82 - Substitutes Subject to Use Restrictions Listed in the December 20, 2011, Final Rule, Effective February 21, 2012, in the April 10, 2015 Final Rule, Effective May 11, 2015, and in the August 8, 2018 Final Rule, Effective September 7, 2018

Substitutes That Are Acceptable Subject to Use Conditions

End-use	Substitute	Decision	Use conditions	Further information
Household refrigerators, freezers, and combination refrigerators and freezers (New equipment only)	Isobutane (R-600a) Propane (R-290) R-441A	Acceptable subject to use conditions	As of September 7, 2018: These refrigerants may be used only in new equipment designed specifically and clearly identified for the refrigerant (i.e., none of these substitutes may be used as a conversion or “retrofit” refrigerant for existing equipment designed for a different refrigerant) These refrigerants may be used only in a refrigerator or freezer, or combination refrigerator and freezer, that meets all requirements listed in the 2nd edition of the Underwriters Laboratories (UL) Standard for Safety: Household and Similar Electrical Appliances - Safety - Part 2-24: Particular Requirements for Refrigerating Appliances, Ice-Cream Appliances and Ice-Makers, UL 60335-2-24, dated April 28, 2017	Applicable OSHA requirements at 29 CFR part 1910 must be followed, including those at 29 CFR 1910.106 (flammable and combustible liquids), 1910.110 (storage and handling of liquefied petroleum gases), 1910.157 (portable fire extinguishers), and 1910.1000 (toxic and hazardous substances). Proper ventilation should be maintained at all times during the manufacture and storage of equipment containing hydrocarbon 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 re-entry should occur only after the space has been properly ventilated. Technicians and equipment manufacturers should wear appropriate personal protective equipment, including chemical goggles and protective gloves, when handling these refrigerants. Special care should be taken to avoid contact with the skin since these refrigerants, 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 refrigerators and freezers with these refrigerants. Any recovery equipment used should be designed for flammable refrigerants. Any refrigerant releases should be in a well-ventilated area, such as outside of a building.
				Only technicians specifically trained in handling flammable refrigerants should service refrigerators and freezers containing these refrigerants. Technicians should gain an understanding of minimizing the risk of fire and the steps to use flammable refrigerants safely.
Retail food refrigerators and freezers (stand-alone units only) (New equipment only)	Isobutane (R-600a) Propane (R-290) R-441A	Acceptable subject to use conditions	As provided in clauses SB6.1.2 to SB6.1.5 of UL Standard 471, 10th edition, the following markings must be attached at the locations provided and must be permanent: (a) On or near any evaporators that can be contacted by the consumer: “DANGER - Risk of Fire or Explosion. Flammable Refrigerant Used. Do Not Use Mechanical Devices To Defrost Refrigerator. Do Not Puncture Refrigerant Tubing.” (b) Near the machine compartment: “DANGER - Risk of Fire or Explosion. Flammable Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant Tubing.” (c) Near the machine compartment: “CAUTION - Risk of Fire or Explosion. Flammable Refrigerant Used. Consult Repair Manual/Owner's Guide Before Attempting To Service This Product. All Safety Precautions Must be Followed.” (d) On the exterior of the refrigerator: “CAUTION - Risk of Fire or Explosion. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.” (e) Near any and all exposed refrigerant tubing: “CAUTION - Risk of Fire or Explosion Due To Puncture Of Refrigerant Tubing; Follow Handling Instructions Carefully. Flammable Refrigerant Used.” All of these markings must be in letters no less than 6.4 mm (1/4 inch) high The refrigerator or freezer must have red, Pantone® Matching System (PMS) #185 marked pipes, hoses, and other devices through which the refrigerant is serviced, typically known as the service port, to indicate the use of a flammable refrigerant. This color must be present at all service ports and where service puncturing or otherwise creating an opening from the refrigerant circuit to the atmosphere might be expected (e.g., process tubes). The color mark must extend at least 2.5 centimeters (1 inch) from the compressor and must be replaced if removed	Room occupants should evacuate the space immediately following the accidental release of this refrigerant. If a service port is added then retail food refrigerators and freezers using these refrigerants should have service aperture fittings that differ from fittings used in equipment or containers using non-flammable refrigerant. “Differ” means that either the diameter differs by at least 1/16 inch or the thread direction is reversed (i.e., right-handed vs. left-handed). These different fittings should be permanently affixed to the unit at the point of service and maintained until the end-of-life of the unit, and should not be accessed with an adaptor.
Very low temperature refrigeration Non-mechanical heat transfer (New equipment only)	Ethane (R-170)	Acceptable subject to use conditions	This refrigerant may be used only in new equipment specifically designed and clearly identified for the refrigerant (i.e., the substitute may not be used as a conversion or “retrofit” refrigerant for existing equipment designed for other refrigerants) This refrigerant may only be used in equipment that meets all requirements in Supplement SB to the 10th edition of the Underwriters Laboratories (UL) Standard for Commercial Refrigerators and Freezers, UL 471, dated November 24, 2010. In cases where the final rule includes requirements more stringent than those of the 10th edition of UL 471, the appliance must meet the requirements of the final rule in place of the requirements in the UL Standard The charge size for the equipment must not exceed 150 g (5.29 oz) in each circuit	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), 1910.157 (portable fire extinguishers), and 1910.1000 (toxic and hazardous substances). Proper ventilation should be maintained at all times during the manufacture and storage of equipment containing hydrocarbon 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 re-entry should occur only after the space has been properly ventilated. Technicians and equipment manufacturers should wear appropriate personal protective equipment, including chemical goggles and protective gloves, when handling ethane. Special care should be taken to avoid contact with the skin since ethane, 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 equipment with flammable refrigerants. Any recovery equipment used should be designed for flammable refrigerants. Any refrigerant releases should be in a well-ventilated area, such as outside of a building. Only technicians specifically trained in handling flammable refrigerants should service equipment containing ethane. Technicians should gain an understanding of minimizing the risk of fire and the steps to use flammable refrigerants safely.
Very low temperature refrigeration Non-mechanical heat transfer (New equipment only)	Ethane (R-170)	Acceptable subject to use conditions	As provided in clauses SB6.1.2 to SB6.1.5 of UL Standard 471, 10th edition, the following markings must be attached at the locations provided and must be permanent: (a) On or near any evaporators that can be contacted by the consumer: “DANGER - Risk of Fire or Explosion. Flammable Refrigerant Used. Do Not Use Mechanical Devices To Defrost Refrigerator. Do Not Puncture Refrigerant Tubing.” (b) Near the machine compartment: “DANGER - Risk of Fire or Explosion. Flammable Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant Tubing.” (c) Near the machine compartment: “CAUTION - Risk of Fire or Explosion. Flammable Refrigerant Used. Consult Repair Manual/Owner's Guide Before Attempting To Service This Product. All Safety Precautions Must be Followed.” (d) On the exterior of the refrigerator: “CAUTION - Risk of Fire or Explosion. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.” (e) Near any and all exposed refrigerant tubing: “CAUTION - Risk of Fire or Explosion Due To Puncture Of Refrigerant Tubing; Follow Handling Instructions Carefully. Flammable Refrigerant Used.” All of these markings must be in letters no less than 6.4 mm (1/4 inch) high The refrigeration equipment must have red, Pantone® Matching System (PMS) #185 marked pipes, hoses, and other devices through which the refrigerant is serviced, typically known as the service port, to indicate the use of a flammable refrigerant. This color must be present at all service ports and where service puncturing or otherwise creating an opening from the refrigerant circuit to the atmosphere might be expected (e.g., process tubes). The color mark must extend at least 2.5 centimeters (1 inch) from the compressor and must be replaced if removed	Room occupants should evacuate the space immediately following the accidental release of this refrigerant. If a service port is added then refrigeration equipment using this refrigerant should have service aperture fittings that differ from fittings used in equipment or containers using non-flammable refrigerant. “Differ” means that either the diameter differs by at least 1/16 inch or the thread direction is reversed (i.e., right-handed vs. left-handed). These different fittings should be permanently affixed to the unit at the point of service and maintained until the end-of-life of the unit, and should not be accessed with an adaptor. Example of non-mechanical heat transfer using this refrigerant would be use in a secondary loop of a thermosiphon.
Vending Machines (New equipment only)	Isobutane (R-600a) Propane (R-290) R-441A	Acceptable subject to use conditions	These 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). Detaching and replacing the old refrigeration circuit from the outer casing of the equipment with a new one containing a new evaporator, condenser, and refrigerant tubing within the old casing is considered “new” equipment and not a retrofit of the old, existing equipment These substitutes may only be used in equipment that meets all requirements in Supplement SA to the 7th edition of the Underwriters Laboratories (UL) Standard for Refrigerated Vending Machines, UL 541, dated December, 2011. In cases where the final rule includes requirements more stringent than those of the 7th edition of UL 541, the appliance must meet the requirements of the final rule in place of the requirements in the UL Standard The charge size for vending machines must not exceed 150 g (5.29 oz) in each circuit	Applicable OSHA requirements at 29 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), 1910.157 (portable fire extinguishers), and 1910.1000 (toxic and hazardous substances). Proper ventilation should be maintained at all times during the manufacture and storage of equipment containing hydrocarbon 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 re-entry should occur only after the space has been properly ventilated. Technicians and equipment manufacturers should wear appropriate personal protective equipment, including chemical goggles and protective gloves, when handling these refrigerants. Special care should be taken to avoid contact with the skin since these refrigerants, 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 refrigeration equipment with flammable refrigerants. Any recovery equipment used should be designed for flammable refrigerants. Any refrigerant releases should be in a well-ventilated area, such as outside of a building. 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.
Vending Machines (New equipment only)	Isobutane (R-600a) Propane (R-290) R-441A	Acceptable subject to use conditions	As provided in clauses SA6.1.2 to SA6.1.5 of UL Standard 541, 7th edition, the following markings must be attached at the locations provided and must be permanent: (a) On or near any evaporators that can be contacted by the consumer: “DANGER - Risk of Fire or Explosion. Flammable Refrigerant Used. Do Not Use Mechanical Devices To Defrost Refrigerator. Do Not Puncture Refrigerant Tubing.” (b) Near the machine compartment: “DANGER - Risk of Fire or Explosion. Flammable Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant Tubing.” (c) Near the machine compartment: “CAUTION - Risk of Fire or Explosion. Flammable Refrigerant Used. Consult Repair Manual/Owner's Guide Before Attempting To Service This Product. All Safety Precautions Must be Followed.” (d) On the exterior of the refrigerator: “CAUTION - Risk of Fire or Explosion. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.” (e) Near any and all exposed refrigerant tubing: “CAUTION - Risk of Fire or Explosion Due To Puncture Of Refrigerant Tubing; Follow Handling Instructions Carefully. Flammable Refrigerant Used.” All of these markings must be in letters no less than 6.4 mm (1/4 inch) high The refrigeration equipment must have red, Pantone® Matching System (PMS) #185 marked pipes, hoses, and other devices through which the refrigerant is serviced, typically known as the service port, to indicate the use of a flammable refrigerant. This color must be present at all service ports and where service puncturing or otherwise creating an opening from the refrigerant circuit to the atmosphere might be expected (e.g., process tubes). The color mark must extend at least 2.5 centimeters (1 inch) from the compressor and must be replaced if removed	Room occupants should evacuate the space immediately following the accidental release of this refrigerant. If a service port is added then refrigeration equipment using this refrigerant should have service aperture fittings that differ from fittings used in equipment or containers using non-flammable refrigerant. “Differ” means that either the diameter differs by at least 1/16 inch or the thread direction is reversed (i.e., right-handed vs. left-handed). These different fittings should be permanently affixed to the unit at the point of service and maintained until the end-of-life of the unit, and should not be accessed with an adaptor.
Residential and light-commercial air conditioning and heat pumps - self-contained room air conditioners only (New equipment only)	HFC-32 Propane (R-290) R-441A	Acceptable subject to use conditions	These 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 refrigerants may only be used in equipment that meets all requirements in Supplement SA and Appendices B through F of the 8th edition of the Underwriters Laboratories (UL) Standard for Room Air Conditioners, UL 484, dated August 3, 2012. In cases where the final rule includes requirements more stringent than those of the 8th edition of UL 484, the appliance must meet the requirements of the final rule in place of the requirements in the UL Standard The charge size for the entire air conditioner must not exceed the maximum refrigerant mass determined according to Appendix F of UL 484, 8th edition for the room size where the air conditioner is used. The charge size for these three refrigerants must in no case exceed 7,960 g (280.8 oz or 17.55 lb) of HFC-32; 1,000 g (35.3 oz or 2.21 lbs) of propane; or 1,000 g (35.3 oz or 2.21 lb) of R-441A. For portable air conditioners, the charge size must in no case exceed 2,450 g (80.0 oz or 5.0 lb) of HFC-32; 300 g (10.6 oz or 0.66 lbs) of propane; or 330 g (11.6 oz or 0.72 lb) of R-441A. The manufacturer must design a charge size for the entire air conditioner that does not exceed the amount specified for the unit's cooling capacity, as specified in Table A, B, C, D, or E of this Appendix	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), 1910.157 (portable fire extinguishers), and 1910.1000 (toxic and hazardous substances). Proper ventilation should be maintained at all times during the manufacture and storage of equipment containing hydrocarbon 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 re-entry should occur only after the space has been properly ventilated. Technicians and equipment manufacturers should wear appropriate personal protective equipment, including chemical goggles and protective gloves, when handling these refrigerants. Special care should be taken to avoid contact with the skin since these refrigerants, 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. Any refrigerant releases should be in a well-ventilated area, such as outside of a building. 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.
Residential and light-commercial air conditioning and heat pumps - self-contained room air conditioners only (New equipment only)	HFC-32 Propane (R-290) R-441A	Acceptable subject to use conditions	As provided in clauses SA6.1.2 to SA6.1.5 of UL 484, 8th edition, the following markings must be attached at the locations provided and must be permanent: (a) On the outside of the air conditioner: “DANGER - Risk of Fire or Explosion. Flammable Refrigerant Used. To Be Repaired Only By Trained Service Personnel. Do Not Puncture Refrigerant Tubing.” (b) On the outside of the air conditioner: “CAUTION - Risk of Fire or Explosion. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.” (c) On the inside of the air conditioner near the compressor: “CAUTION - Risk of Fire or Explosion. Flammable Refrigerant Used. Consult Repair Manual/Owner's Guide Before Attempting To Service This Product. All Safety Precautions Must be Followed.” (d) On the outside of each portable air conditioner: “WARNING: Appliance hall be installed, operated and stored in a room with a floor area larger the “X” m2 (Y ft2).” The value “X” on the label must be determined using the minimum room size in m2 calculated using Appendix F of UL 484, 8th edition. For R-441A, use a lower flammability limit of 0.041 kg/m3 in calculations in Appendix F of UL 484, 8th edition All of these markings must be in letters no less than 6.4 mm (1/4 inch) high The air conditioning equipment must have red, Pantone® Matching System (PMS) #185 marked pipes, hoses, and other devices through which the refrigerant is serviced, typically known as the service port, to indicate the use of a flammable refrigerant. This color must be present at all service ports and where service puncturing or otherwise creating an opening from the refrigerant circuit to the atmosphere might be expected (e.g., process tubes). The color mark must extend at least 2.5 centimeters (1 inch) from the compressor and must be replaced if removed	Room occupants should evacuate the space immediately following the accidental release of this refrigerant. If a service port is added then air conditioning equipment using this refrigerant should have service aperture fittings that differ from fittings used in equipment or containers using non-flammable refrigerant. “Differ” means that either the diameter differs by at least 1/16 inch or the thread direction is reversed (i.e., right-handed vs. left-handed). These different fittings should be permanently affixed to the unit at the point of service and maintained until the end-of-life of the unit, and should not be accessed with an adaptor. Air conditioning equipment in this category includes: Window air conditioning units. Portable room air conditioners. Packaged terminal air conditioners and heat pumps.

Note: The use conditions in this appendix contain references to certain standards from Underwriters Laboratories Inc. (UL). The standards are incorporated by reference, and the referenced sections are made part of the regulations in part 82:

1. UL 471. Commercial Refrigerators and Freezers. 10th edition. Supplement SB: Requirements for Refrigerators and Freezers Employing a Flammable Refrigerant in the Refrigerating System. Underwriters Laboratories, Inc. November 24, 2010.

2. UL 484. Room Air Conditioners. 8th edition. Supplement SA: Requirements for Room Air Conditioners Employing a Flammable Refrigerant in the Refrigerating System and Appendices B through F. December 21, 2007, with changes through August 3, 2012.

3. UL 541. Refrigerated Vending Machines. 7th edition. Supplement SA: Requirements for Refrigerated Venders Employing a Flammable Refrigerant in the Refrigerating System. December 30, 2011.

4. UL Standard 60335-2-24. Standard for Safety: Requirements for Household and Similar Electrical Appliances, - Safety - Part 2-24: Particular Requirements for Refrigerating Appliances, Ice-Cream Appliances and Ice-Makers, Second edition, dated April 28, 2017.

The Director of the Federal Register approves the incorporation by reference of the material under “Use Conditions” in the table “SUBSTITUTES THAT ARE ACCEPTABLE SUBJECT TO USE CONDITIONS” (5 U.S.C. 552(a) and 1 CFR part 51). Copies of UL Standards 471, 484, 541, and 60335-2-24, may be purchased by mail at: COMM 2000, 151 Eastern Avenue, Bensenville, IL 60106; Email: [e-mail]; Telephone: [phone] in the U.S. or Canada (other countries dial 1-415-352-2178); internet address: http://www.shopulstandards.com/Catalog.aspx.

You may inspect a copy at U.S. EPA's Air Docket; EPA West Building, Room 3334; 1301 Constitution Ave. NW, Washington, DC or at the National Archives and Records Administration (NARA). For questions regarding access to these standards, the telephone number of EPA'S Air Docket is 202-566-1742. For information on the availability of this material at NARA, call 202-741-6030, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

[80 FR 19491, Apr. 10, 2015, as amended at 83 FR 38975, Aug. 8, 2018]