Regulations last checked for updates: Nov 22, 2024

Title 40 - Protection of Environment last revised: Nov 20, 2024
Appendix Appendix R - 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

Substitutes That Are Acceptable Subject to Use Conditions

End-use Substitute Decision Use conditions Further information
1. Household refrigerators, freezers, and combination refrigerators and freezers (New equipment only)Isobutane (R-600a), Propane (R-290), R-441AAcceptable subject to use conditionsAs 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 requirements listed in UL 60335-2-24. 1 2 6
Applicable OSHA requirements at 29 CFR part 1910 must be followed, including those at 29 CFR 1910.94 (ventilation), 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.
2. Retail Food Refrigeration—stand-alone units only (New equipment only) manufactured on or after February 21, 2012, and up to but not including 7/15/2024Isobutane (R-600a) Propane (R-290) R-441AAcceptable 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 equipment that meets requirements in Supplement SB to UL 471. 1 2 3 In cases where this listing 2 includes requirements more stringent than those of UL 471, the appliance must meet the requirements of this listing 2 in place of the requirements in the UL Standard.
The charge size for the retail food refrigerator or freezer shall not exceed 150 grams (5.3 ounces) in each circuit.
As provided in clauses SB6.1.2 to SB6.1.5 of UL 471, 1 2 3 the following markings shall be attached at the locations provided and shall be permanent:
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 reentry should occur only after the space has been properly ventilated.
Technicians and equipment manufacturers should wear appropriate personal protective
(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 shall be in letters no less than 6.4 mm ( 1/4 inch) high.
The refrigerator or freezer must have red, Pantone® Matching System #185 or RAL 3020 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.
equipment, including chemical goggles and protective gloves, when handling propane. Special care should be taken to avoid contact with the skin since propane, 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 propane.
Recovery equipment designed for flammable refrigerants should be used.
Only technicians specifically trained in handling flammable refrigerants should service refrigerators and freezers 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.
If a service port is added then stand-alone retail food refrigeration units 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.
3. Retail Food Refrigeration—stand-alone units only (New equipment only) manufactured from 7/15/2024, through September 29, 2024, or equipment manufactured on or after September 30, 2024, except for equipment manufactured on or after September 30, 2024, that remains unchanged, other than cosmetic changes, from an earlier model or design that was already certified to the UL 471 1 2 3 standard before September 30, 2024Isobutane (R-600a) Propane (R-290) R-441AAcceptable subject to use conditionsThese substitutes may only be used in equipment that meets requirements of either:
1. Supplement SB to UL 471 1 2 3 and listing 2 of this table or
2. ASHRAE 15-2022, 1 9 12 UL 60335-2-89, 1 2 8 and listing 4 of this table.
4. Retail Food Refrigeration—stand-alone units only (New equipment only) manufactured on or after September 30, 2024, except for equipment manufactured on or after September 30, 2024, that remains unchanged, other than cosmetic changes, from an earlier model or design that was already certified to the UL 471 1 2 3 standard before September 30, 2024Isobutane (R-600a) Propane (R-290) R-441AAcceptable subject to use conditionsThis refrigerant may be used only in new equipment specifically designed and clearly identified for the refrigerant (i.e., this substitute may not be used as a conversion or “retrofit” refrigerant for existing equipment designed for other refrigerants).
This refrigerant may be used in new stand-alone units if and only if such equipment meets all requirements listed in ASHRAE 15-2022. 1 9 12 In cases where this listing 4 includes requirements different than those of ASHRAE 15-2022, the appliance would need to meet the requirements of this listing in addition to the requirements in ASHRAE 15-2022.
This refrigerant may only be used in stand-alone units that meet all requirements in UL 60335-2-89 1 2 8 except as provided otherwise in UL 60335-2-89, in ASHRAE 15-2022, 1 9 12 or in this listing 4. In cases where this listing includes requirements more stringent than those of UL 60335-2-89, the appliance must meet the requirements of this listing 4 in addition to requirements in UL 60335-2-89. Where similar requirements of ASHRAE 15-2022 and UL 60335-2-89 differ, the more stringent or conservative condition shall apply unless superseded by this listing 4.
The following markings must be attached at the locations provided and must be permanent:
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 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.
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
(a) On the outside of the equipment: “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 equipment: “WARNING—Risk of Fire Or Explosion. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.”
(c) On the inside of the equipment near the compressor: “DANGER—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) For any equipment pre-charged at the factory, on the equipment packaging or on the outside of the equipment: “WARNING—Risk of Fire Due to Flammable Refrigerant Used. Follow Handling Instructions Carefully in Compliance with National Regulations.”
a. If the equipment is delivered packaged, this label shall be applied on the packaging.
when working on equipment containing 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.
Any person commissioning, maintaining, repairing, decommissioning, and disposing of appliances with this refrigerant should obtain training and follow practices consistent with Annex 101.DVT of UL 60355-2-89, 2nd edition. 1 2 8
Department of Transportation requirements for transport of flammable gases must be followed.
Flammable refrigerants being recovered or otherwise disposed of from stand-alone units are likely to be hazardous waste under the Resource Conservation and Recovery Act (RCRA) (see 40 CFR parts 260 through 270).
b. If the equipment is not delivered packaged, this label shall be applied on the outside of the equipment near the control panel or nameplate.
(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 60335-2-89. The terms “X” and “W” shall be replaced by the numeric height as calculated per UL 60335-2-89. Note that the formatting here is slightly different than UL 60335-2-89; 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 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 UL 60335-2-89. Note that the formatting here is slightly different than UL 60335-2-89; specifically, the area in Inch-Pound units is placed in parentheses and the word “and” has been replaced by the opening parenthesis.
(f) For non-fixed equipment, 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 that is ducted, near the nameplate: “WARNING—Risk Of Fire Or Explosion—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 #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.
In addition to or instead of the markings described in Clause 7.6DV D1 of UL 60335-2-89, 1 2 8 the equipment may display the GHS warning symbol for hazard category 1 flammable gases (black flame on a white background in a diamond with equal length sides with a red border), as defined in Chapter 2.2, Flammable Gasses, and Annex 1, Classification and Labelling Summary Tables, of ST/SG/AC.10/30/Rev.9, Global Harmonized System (GHS) of Classification and Labelling of Chemicals, Ninth revised edition 1 13 14 on the following three locations:
• Outside of the equipment (label (a));
• on the appliance packaging for a factory-charged unit or adjacent to the control panel or nameplate of a unit charged in place (label (d)); and
• in a location visible when accessing a service port and where service puncturing or otherwise creating an opening from the refrigerant circuit to the atmosphere might be expected (e.g., process tubes) (service label).
The perpendicular height of the diamond containing the GHS warning symbol for hazard category 1 flammable gases shall be at least 15 mm ( 9/16 in). In addition, next to the GHS warning symbol for hazard category 1 flammable gases must be text of the refrigerant safety class of the refrigerant according to ASHRAE 34-2022, 1 9 10 11 in letters at least one-third the height of the diamond symbol.
5. Very low temperature refrigeration. Non-mechanical heat transfer (New equipment only)Ethane (R-170)Acceptable subject to use conditionsThis 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 requirements in Supplement SB to UL 471. 1 2 3 In cases where this listing 5 of this table includes requirements more stringent than those of UL 471, the appliance must meet the requirements of listing 5 of this table in place of the requirements in UL 471.
The charge size for the equipment must not exceed 150 g (5.29 oz) in each circuit.
As provided in clauses SB6.1.2 to SB6.1.5 of UL 471, 1 2 3 the following markings must be attached at the locations provided and must be permanent:
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
(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 #185 or RAL 3020 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.
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. 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.
An example of non-mechanical heat transfer using this refrigerant would be use in a secondary loop of a thermosiphon.
6. Vending machines (New equipment only)Isobutane (R-600a), Propane (R-290), R-441AAcceptable 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). 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 requirements in Supplement SA to UL 541. 1 2 5 In cases where this listing 6 of this table includes requirements more stringent than those of UL 541, the appliance must meet the requirements of this listing 6 of this table in place of the requirements in UL 541. The charge size for vending machines must not exceed 150 g (5.29 oz) in each circuit.
As provided in clauses SA6.1.2 to SA6.1.5 of UL 541, 1 2 5 the following markings must be attached at the locations provided and must be permanent:
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) 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.”
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.
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 #185 or RAL 3020 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.
7. Residential and light-commercial air conditioning and heat pumps—self-contained room air conditioners only (New equipment only)Propane (R-290), R-441AAcceptable 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 refrigerants may only be used in equipment that meets requirements in Supplement SA and Appendices B through F of UL 484. 1 2 4 In cases where listing 7 of this table includes requirements more stringent than those of UL 484, the appliance must meet the requirements of this listing 7 of this table in place of the requirements in UL 484.
The charge size for the entire air conditioner must not exceed the maximum refrigerant mass determined according to Appendix F of UL 484 for the room size where the air conditioner is used. The charge size for these three refrigerants must in no case exceed 1,000 g (35.3 oz or 2.21 pounds) of propane or 1,000 g (35.3 oz or 2.21 pounds) of R-441A. For portable air conditioners, the charge size must in no case exceed 300 g (10.6 oz or 0.66 pounds) of propane or 330 g (11.6 oz or 0.72 pounds) 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 R.
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.
As provided in clauses SA6.1.2 to SA6.1.5 of UL 484, 1 2 4 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 shall be installed, operated and stored in a room with a floor area larger the “X” m 2 (Y ft 2).” The value “X” on the label must be determined using the minimum room size in m 2 calculated using Appendix F of UL 484. For R-441A, use a lower flammability limit of 0.041 kg/m 3 in calculations in Appendix F of UL 484.
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 #185 or RAL 3020 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.
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 air conditioning 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.
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.
Examples of air conditioning equipment in this category include window air conditioning units, portable room air conditioners, and packaged terminal air conditioners and heat pumps.
8. Residential and light-commercial air conditioning and heat pumps—self-contained room air conditioners only (New equipment only) manufactured from May 10, 2015, and up to but not including May 30, 2023HFC-32Acceptable subject to use conditionsThis refrigerant may be used only in new equipment specifically designed and clearly identified for the refrigerant (i.e., this 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 SA and Appendices B through F of UL 484. 1 2 4 In cases where this listing 8 of this table includes requirements more stringent than those of UL 484, the appliance must meet the requirements of listing 8 of this table in place of the requirements in UL 484.
The charge size for the entire air conditioner must not exceed the maximum refrigerant mass determined according to Appendix F of UL 484 for the room size where the air conditioner is used. 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.
For equipment following this listing 8, and as provided in clauses SA6.1.2 to SA6.1.5 of UL 484, 1 2 4 the following markings must be attached at the locations provided and must be permanent:
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.
(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 shall be installed, operated and stored in a room with a floor area larger the “X” m 2 (Y ft 2).” The value “X” on the label must be determined using the minimum room size in m 2 calculated using Appendix F of UL 484.
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.
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.
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.
9. Residential and light-commercial air conditioning and heat pumps—self-contained room air conditioners only (New equipment only) manufactured from May 30, 2023 through January 1, 2024HFC-32Acceptable subject to use conditionsThis refrigerant may only be used in equipment that meets all requirements in either:
(1) Supplement SA and Appendices B through F of UL 484 1 2 4 and listing 8 of this table, or
(2) UL 60335-2-40 1 2 7 and listing 10 of this table.
10. Residential and light-commercial air conditioning and heat pumps—self-contained room air conditioners only. (New equipment only) manufactured on or after January 2, 2024HFC-32Acceptable subject to use conditionsThis refrigerant may be used only in new equipment specifically designed and clearly identified for the refrigerant (i.e., this substitute may not be used as a conversion or “retrofit” refrigerant for existing equipment designed for other refrigerants).
This substitute may only be used in air conditioning equipment that meets all requirements in UL 60335-2-40 1 2 7 and this listing 10 of this table.
In cases where this listing 10 includes requirements more stringent than those of UL 60335-2-40, the appliance must meet the requirements of this listing 10 in place of the requirements in UL 60335-2-40.
The following markings must be attached at the locations provided and must be permanent:
(a) On the outside of the 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 equipment: “WARNING—Risk of Fire. Dispose of Properly In Accordance With Federal Or Local Regulations. Flammable Refrigerant Used.”
(c) On the inside of the 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.”
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.
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 flam-
(d) For any equipment pre-charged at the factory, on the equipment packaging or on the outside of the equipment: “WARNING—Risk of Fire due to Flammable Refrigerant Used. Follow Handling Instructions Carefully in Compliance with National Regulations”
a. If the equipment is delivered packaged, this label shall be applied on the packaging.
b. If the equipment is not delivered packaged, this label shall be applied on the outside of the equipment near the control panel or nameplate.
(e) On the equipment 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 the UL 60335-2-40. The terms “X” and “W” shall be replaced by the numeric height as calculated per UL 60335-2-40. Note that the formatting here is slightly different than UL 60335-2-40; 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 marking (a) of this listing 8 or at the top of the marking if marking (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 UL 60335-2-40. Note that the formatting here is slightly different than UL 60335-2-40; specifically, the area in Inch-Pound units is placed in parentheses and the word “and” has been replaced by the opening parenthesis.
(f) For non-fixed equipment, 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) 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.
mable 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. 2 7
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 through 270).

1 The Director of the Federal Register approves this incorporation by reference (5 U.S.C. 552(a) and 1 CFR part 51). You may inspect a copy at the U.S. EPA or at the National Archives and Records Administration (NARA). Contact the U.S. EPA at: EPA Docket Center, WJC West Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004, https://www.epa.gov/dockets, (202) 566-1742. For information on the availability of this material at NARA, visit https://www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

2 You may obtain the UL material from: Underwriters Laboratories Inc. (UL) COMM 2000; 151 Eastern Avenue; Bensenville, IL 60106; phone: 1-888-853-3503 in the U.S. or Canada (other countries +1-415-352-2168); email: [email protected]; website: https://ulstandards.ul.com or www.shopulstandards.com.

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

4 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.

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

6 UL 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, 2nd edition, dated April 28, 2017.

7 UL 60335-2-40, Standard for Safety: Household And Similar Electrical Appliances—Safety—Part 2-40: Particular Requirements for Electrical Heat Pumps, Air-Conditioners and Dehumidifiers, 3rd edition, dated November 1, 2019.

8 UL 60335-2-89, Standard for Safety for Household and Similar Electrical Appliances—Safety—Part 2-89: Particular Requirements for Commercial Refrigerating Appliances and Ice-Makers with an Incorporated or Remote Refrigerant Unit or Motor-Compressor, 2nd edition, dated October 27, 2021.

9 You may obtain the ANSI/ASHRAE material from: American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), 180 Technology Parkway NW, Peachtree Corners, Georgia 30092; phone: 1-800-527-4723 or 1-404-636-8400 in the U.S. or Canada; email: [email protected]; website: https://www.ashrae.org/technical-resources/bookstore/ashrae-refrigeration-resources.

10 ANSI/ASHRAE Standard 34-2022. Designation and Safety Classification of Refrigerants, copyright 2022.

11 ANSI/ASHRAE Addendum a to ANSI/ASHRAE Standard 34-2022, Designation and Safety Classification of Refrigerants, ANSI-/ASHRAE-approved December 20, 2022.

12 ANSI/ASHRAE Standard 15-2022. Safety Standard for Refrigeration Systems, copyright 2022.

13 You may obtain the material from the United Nations Publications section at: https://shop.un.org/books/global-harmon-syst-class-9-92280; United Nations Publications Customer Service, P.O. Box 960, Herndon, VA 20172; phone: 1-703-661-1571; email: [email protected].

14 ST/SG/AC.10/30/Rev.9, Global Harmonized System (GHS) of Classification and Labelling of Chemicals, Ninth revised edition, copyright 2021; Chapter 2.2, Flammable Gasses, and Annex 1, Classification and Labelling Summary Tables.

[80 FR 19491, Apr. 10, 2015, as amended at 83 FR 38975, Aug. 8, 2018; 88 FR 26418, Apr. 28, 2023; 89 FR 50463, June 13, 2024]
authority: 42 U.S.C. 7414,7601,7671
source: 57 FR 33787, July 30, 1992, unless otherwise noted.