# Hydrofluorocarbon Phasedown: Background and Issues Facing Congress

> Briefs, arguments, decisions, and more.

URL: https://www.frixlaw.com/law-library/documents/crs%3AIF11779

## Record

- **Collection:** Congressional research report
- **Document type:** In Focus
- **Published:** June 30, 2026
- **Citation:** IF11779

## Text

Updated June 30, 2026

Hydrofluorocarbon Phasedown: Background and Issues
Facing Congress
The United States is phasing down hydrofluorocarbons
(HFCs) under the American Innovation and Manufacturing
Act of 2020 (AIM; P.L. 116-260, Division S, §103;
codified at 42 U.S.C. §7675) and the Kigali Amendment to
the Montreal Protocol (MP). HFCs are greenhouse gases
(GHGs) used in refrigeration and air conditioning, aerosols,
foam blowing, fire suppression, solvents, semiconductor
manufacturing, and other applications. HFCs gained
widespread use as substitutes for ozone-depleting
substances (ODSs), which have largely been phased out
worldwide under the MP. According to scientists, HFCs
have a negligible impact on stratospheric ozone but are
potent GHGs. Their potency, measured as Global Warming
Potential (GWP), can be hundreds to thousands of times
greater than the equivalent mass of carbon dioxide (CO2)
when measured over near-term time horizons (e.g., 20 or
100 years).

Kigali Amendment to the Montreal
Protocol (MP)

Parties to the Vienna Convention for the Protection of the
Ozone Layer, including the United States, adopted the MP
in 1987 to set binding schedules for countries to phase out
listed ODSs, which were largely replaced by HFCs as
substitutes. The MP also provides for international
cooperation on ODS substitutes, research, and financial
assistance—including through its Multilateral Fund—and
trade restrictions with nonparties.
In 2016, MP parties agreed to phase down HFCs through
the Kigali Amendment. The Kigali Amendment requires
ratifying countries to phase down the production and
consumption of 18 HFCs. Nondeveloping (or non-Article 5)
countries, including the United States, must reduce HFC
production and consumption by 85% by 2036. Developing
(or Article 5) countries must reduce HFC production and
consumption to either 80% by 2045 or 85% by 2047. Most
Article 5 countries froze HFC consumption levels in 2024,
while a smaller group of Article 5 countries with high
ambient temperatures are to freeze consumption in 2028.
The Kigali Amendment updates the MP’s financial
mechanism to support Article 5 countries’ incremental costs
of compliance. It also sets a 2033 deadline for parties to ban
trade of HFCs with any country that has not ratified the
amendment. The Kigali Amendment entered into force in
2019. The United States ratified it in 2022. As of December
2025, there were 172 parties to the Kigali Amendment.
According to the National Oceanic and Atmospheric
Administration, scientists estimate that compliance with the
Kigali Amendment could avoid 0.3–0.5o Celsius of global
warming by 2100, relative to a scenario without controls.

American Innovation and Manufacturing
Act of 2020 (AIM)

AIM addresses domestic HFC use in three main ways: (1)
phasing down HFC production and consumption through an
allowance allocation program administered by the U.S.
Environmental Protection Agency (EPA); (2) facilitating
the transition to “next-generation technologies” by
authorizing EPA to restrict the use of HFCs in the sector or
subsectors in which they are used; and (3) directing EPA to
promulgate regulations for purposes of maximizing
reclaiming and minimizing releases of HFCs from
equipment. Examples of “next-generation technologies”
include hydrofluoroolefins (HFOs), which are sometimes
referred to as “natural refrigerants” (e.g., CO2, ammonia,
and propane), and lower-GWP HFC blends.
AIM establishes a 15-year timeline to reduce domestic HFC
production and consumption. AIM’s phasedown schedule
aligns with multiple aspects of international obligations to
phase down HFCs under the Kigali Amendment to the MP.
In AIM, production refers to the quantity of HFCs made in
the United States, while consumption refers to the HFC
domestic production plus imports minus exports. AIM
phases down the same 18 HFCs as the Kigali Amendment.
Benchmarking from a 2011-2013 baseline, AIM requires a
10% reduction in production and consumption within the
first time period, 2020-2023, and an 85% reduction by the
last, 2036 and beyond. AIM does not completely eliminate
HFCs (see Table 1) and allows limited exceptions such as
for essential uses, including for asthma inhalers and
military fire suppression.
Table 1. American Innovation and Manufacturing Act
of 2020 (AIM) Phasedown of HFCs
Percentage of
Reduction in
HFC
Production

Percentage of
Reduction in
HFC
Consumption

2020-2023

10%

10%

2024-2028

40%

40%

2029-2033

70%

70%

2034-2035

80%

80%

2036 and beyond

85%

85%

Time Period

Source: AIM, 42 U.S.C. §7675 (e)(2).
Note: The percentages shown are relative to production and
consumption baselines specified in 42 U.S.C. §7675 (e)(1). The United
States completed the initial 10% reduction phase and is currently
implementing the 40% reduction step.

https://crsreports.congress.gov

Hydrofluorocarbon Phasedown: Background and Issues Facing Congress

AIM directs EPA to administer an allowance allocation and
trading program to implement the HFC phasedown.
Pursuant to this mandate, EPA issues annual allowances for
the production and consumption of HFCs, as well as
application-specific allowances. AIM also addresses
international trade of HFCs. It provides for EPA to reduce
the number of U.S. production allowances when HFCs are
exported and bans the export of HFCs to any country that
has not enacted comparable requirements starting in 2023.
The U.S. Court of Appeals for the D.C. Circuit has twice
upheld EPA’s HFC allowance allocations and trading
regulations.
AIM authorizes EPA to evaluate petitions from any person
to accelerate the phasedown schedule after 2024. Under the
law, EPA must consider factors such as availability of
substitutes, costs, and environmental impacts when
deciding on petitions.
To support this HFC phasedown, EPA’s Technology
Transitions Program limits HFCs in specific sectors
including refrigeration, air conditioning, heat pumps,
foams, and aerosols. Technology Transition rules require
shifts to lower-GWP alternatives in particular equipment
and applications beginning in 2025, some of which EPA
announced in March 2025 that it would reconsider. As a
part of that reconsideration, in May 2026 EPA issued a final
rule extending the compliance deadlines and revising
certain GWP limits and other HFC requirements for
specific sectors and subsectors, including residential air
conditioning, retail food refrigeration, cold storage
warehouses, and semiconductor manufacturing.
In addition, EPA has established a program for managing
use and reuse of HFCs and substitutes, which regulates the
management of HFCs used in equipment, such as
refrigeration and air conditioning systems. As part of the
program, EPA has established requirements for the
installation, servicing, repair, and disposal of equipment
containing HFCs and their substitutes.
The FY2022 reconciliation law (P.L. 117-169), sometimes
referred to as the Inflation Reduction Act, appropriated
$38.5 million for EPA to implement AIM, including $15
million for small business grants and $22.5 million for
implementation and compliance. The FY2025
reconciliation law (P.L. 119-21), sometimes referred to as
the One Big Beautiful Bill Act, rescinded unobligated funds
previously appropriated under P.L. 117-169 to support
EPA’s implementation of AIM.

Considerations for Congress

Congress may consider several issues related to HFCs and
their phasedown:

• Congress may consider oversight of U.S. participation in
the international phasedown of HFCs under the Kigali
Amendment. Areas of oversight may include
compliance with international obligations, level of U.S.
engagement in international decisionmaking, scientific
and technical activities, and implementation-related

coordination. Changes in staffing levels, organizational
structure, or resource availability across agencies such
as the State Department and EPA may affect capacity
for U.S. participation in international cooperation to
phase down HFCs.

• Congress may consider oversight, including hearings or

legislation, regarding risks of illegal trade or
misreporting of bulk HFCs and pre-charged equipment,
such as air conditioning and refrigeration equipment,
and coordination among EPA, U.S. Customs and Border
Protection, and international partners. Oversight may
include implementation of reporting requirements,
enforcement activities, and federal monitoring programs
that support detection of illegal trade and global
compliance with HFC phasedown obligations.

• Congress may conduct oversight of domestic HFC

phasedown activities, including EPA’s allowance
allocation and trading program, Technology Transitions
rules and associated reconsiderations, and HFC
management and reclamation requirements. The
provisions in the rules—and the extent to which they are
reconsidered, implemented, and enforced—may affect
the pace of the U.S. phasedown of HFCs, its alignment
with Kigali Amendment obligations, and
implementation of the AIM Act. Some stakeholders
have raised concerns about the domestic implementation
of the phasedown, including potential consumer costs,
compliance burdens, and implementation challenges.
Others contend that these measures provide market
certainty and investment signals that support the
transition to lower-GWP alternatives and U.S. industry
competitiveness in emerging global markets as well as
facilitate progress toward phasedown requirements.

• Congress may also evaluate or appropriate additional

funding to support implementation of the HFC
phasedown under the Kigali Amendment and AIM. This
could include bilateral or multilateral international
support for HFC phasedown, such as U.S. contributions
to the Multilateral Fund of the MP. Congress could also
consider the role of domestic incentives—such as
rebates or grants—in supporting adoption rates, market
transitions, and consumer costs. For example, EPA has
administered grants to support small businesses. Future
appropriations could include similar programs or other
incentives supporting the HFC phasedown. For
example, programs could include federal grants and
incentive programs, such as grants for commercial and
industrial refrigeration or federal incentive programs for
air conditioning with lower-GWP refrigerants. Congress
also may determine that additional funding or incentives
are not needed to support implementation of the HFC
phasedown.

Kathryn G. Kynett, Analyst in Environmental Policy
Kristen Hite, Legislative Attorney

www.crs.gov | 7-5700

IF11779

Hydrofluorocarbon Phasedown: Background and Issues Facing Congress

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to
congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress.
Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has
been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the
United States Government, are not subject to copyright protection in the United States. Any CRS Report may be
reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include
copyrighted images or material from a third party, you may need to obtain the permission of the copyright holder if you
wish to copy or otherwise use copyrighted material.

https://crsreports.congress.gov | IF11779 · VERSION 7 · UPDATED

---

Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3AIF11779. Public record. Not legal advice.
