Regulation Database – Hydrochlorofluorocarbons (HCFCs) and Hydrofluorocarbons (HFCs)

On December 24, 2013, EPA published a proposed rule on compliance with Clean Air Act and Montreal Protocol requirements for phasing out ozone-depleting hydrochlorofluorocarbons (HCFCs). According to the Protocol, the United States must reduce consumption and production of HCFCs to be no more than 10% of the established cap by January 1, 2015. The proposed rule also proposed changes to section 608 of the Clean Air Act, dealing with HCFC recycling and emissions reductions requirements.

On October 28, 2014, EPA finalized adjustments to the allowance system for consumption and production of HCFCs. The rule lists specific allowances for four HCFCs for 2015 to 2019. The plan dictates that HCFC-22 will be phased out completely by 2020; HCFC-123 will be capped at 2,000 MT per year through 2019; HCFC-124 will be allocated 200 MT per year through 2019; HCFC-142b is allocated 35 MT in 2015, decreasing by 5 MT per year through 2019 and reaching zero at 2020; and HCFC-225ca/cb received zero percent of the baseline.

Kigali Amendment and HFCs

On October 20, 2022, the EPA issued a notice of proposed rulemaking designed to implement the Kigali Amendment to the Montreal Protocol following the Senate’s bipartisan ratification in September of 2022. The Kigali Amendment is a global agreement to phase down climate-damaging hydrofluorocarbons (HFCs), and avoid up to 0.5°C of global warming by the end of this century.

The proposed rules would amend existing regulations to implement certain provisions of the American Innovation and Manufacturing Act, as enacted on December 27, 2020. This rulemaking proposes to establish the methodology for allocating HFC production and consumption allowances for the calendar years of 2024 through 2028. EPA is also proposing to amend the consumption baseline to reflect updated data and to make other adjustments based on lessons learned from implementation of the HFC phasedown program thus far, including proposing to: codify the existing approach of how allowances must be expended for import of regulated substances; revise recordkeeping and reporting requirements; and implement other modifications to the existing regulations.

The EPA is accepting comments until 45 days after publication of this notice in the Federal Register. [Note: This post will be updated with specific comment deadlines when the notice is formally published and the comment period is formally established]

EPA’s Significant New Alternatives Policy (SNAP) program expands the list of acceptable substitutes to ozone-depleting substances, and lists unacceptable substitutes. EPA has been regulating under the program since the early 1990s. Recent EPA rules under the SNAP program have considered global warming potential as a criterion in evaluating the impacts of substances under consideration.

In April 2015, EPA published a rule to name five refrigerants acceptable substitutes to ozone-depleting HCFCs in compliance with the agency’s Significant New Alternatives Policy  (SNAP) program. The substitutes are to be used in several end uses, including household and stand-alone commercial refrigerators, vending machines, and room air conditioning units, subject to use conditions. The substitutes (ethane, isobutane, propane, HFC-32, and R-441A) are legal to use in new appliances, and are exempt from the Clean Air Act Section 608’s prohibition on venting, release, or disposal.

In July 2015, also under the Significant New Alternatives Policy program, EPA made changes to the listing for certain HFCs used in aerosols, refrigeration and air conditioning, and foam blowing, and prohibited the use of HFCs that are powerful greenhouse gases as replacements for ozone-depleting substances.

In December 2016, among other things, EPA listed certain substances as acceptable in refrigeration, air conditioning, and fire suppression; listed several substances as unacceptable in certain end uses in refrigeration and air conditioning; and changed the listing status for certain substances that had been listed as acceptable in refrigeration, air conditioning, and foam blowing. 


On August 8, 2017, the D.C. Circuit Court of Appeals ruled that EPA lacked authority to force regulated entities that had already switched from ozone-depleting substances to HFCs to switch to another substitute. See Mexichem Fluor, Inc. v. EPA, 866 F.3d 451.

Deregulatory Action:

On April 27, 2018, EPA announced that it will not enforce the 2015 SNAP rule, and will begin a notice-and-comment rulemaking to address the remand of the rule.


On April 7, 2020, the D.C. Circuit Court of Appealed ruled that EPA acted unlawfully by announcing that it would not enforce the 2015 rule prohibiting the use of HFCs as substitutes for ozone-depleting substances. The Court explained that in Mexichem, it held that EPA could not compel operators who had already switched to HFCs to make another switch to a new substitute--but that EPA did have the authority to prohibit operators currently using ozone-depleting substances from switching to HFCs in the first place. The Court ruled that EPA could not stop enforcing the 2015 rule without going through notice-and-comment rulemaking. NRDC v. Wheeler, D.C. Cir. 18-1172.

In November 2016, EPA extended safe handling requirements under section 608 of the Clean Air Act that currently apply to ozone depleting refrigerants, extending them to substitutes like hydrofluorocarbons (HFCs). According to EPA estimates, annual GHG emissions reductions from this rule will be approximately 7.3 million metric tons of carbon dioxide equivalent and 114 ozone-depletion weighted metric tons.

Deregulatory Action:

On October 1, 2018, EPA proposed a rule that would amend the 2016 rule by, among other things, rescinding provisions that extend leak repair requirements to appliances using substitute refrigerants. EPA finalized the rule on March 11, 2020.


On May 11, 2020, NRDC filed a challenge to the rollback.

On May 3, 2021, the Environmental Protection Agency (EPA) proposed a rule to create an allowance trading program to phase down the production and consumption of hydrofluorocarbons (HFCs). HFCs became widely used in air-conditioning and refrigeration equipment as substitutes for ozone-depleting substances, but they are powerful greenhouse gases. The HFC rule was proposed pursuant to the American Innovation and Manufacturing Act, which was enacted in December 2020.

EPA finalized its rule establishing an allowance trading program for the phase out of HFCs on September 23, 2021. 

On October 7, 2021, EPA granted ten petitions and partially granted an eleventh to restrict the use of hydrofluorocarbons in the refrigeration, air conditioning, aerosols, and foam sectors. EPAs notice of determination to grant and partially grant these petitions begins a rulemaking process for each use of HFCs. Under the American Innovation and Manufacturing Act of 2020, EPA now has two years to issue final rules, each of which must take effect within one year of their publication. 

Litigation: On December 2, 2021, industry groups filed a petition for review of EPA's September 23, 2021 final rule in the D.C. Circuit Court of Appeals. 

On September 29, 2021, the Environmental Protection Agency proposed a rule under its Clean Air Act authority that would require manufacturing plants to control, capture, and/or destroy HFC-23. HFC-23 is a powerful greenhouse gas that is generated during the manufacture of certain class II ozone-depleting substances, including HCFC-22. According to EPA, HFC-23 has a substantially longer atmospheric lifetime and higher global warming potential than all other HFCs. 

Under the proposed rule, HFC-23 must be captured and employed for a commercial use or destroyed using a technology approved by the Environmental Protection Agency, thereby ensuring it is not directly emitted. The rule would be narrow in scope, only affecting plants that continue to manufacture HCFCs under an exception to the HCFC phaseout under the Clean Air Act and its implementing regulations.