HFC Refrigerants: AIM Act Step-Downs, GWP Limits, and Penalties

The federal phase-down schedule for HFC refrigerants cuts U.S. production and imports to 15 percent of a historical baseline by 2036, stepping down in five tiers under the American Innovation and Manufacturing Act of 2020. A separate EPA rule, running on its own calendar, caps the global warming potential of refrigerants allowed in newly manufactured equipment. Together, the two tracks determine what refrigerant you can buy, what equipment you can install, and what it will cost to keep older systems running.

The AIM Act Step-Down Percentages

The AIM Act works through tradable allowances. Every producer or importer of HFCs must hold enough allowances to cover its volume, and the EPA shrinks the total pool on a fixed schedule tied to a baseline built from each company’s three highest production or import years between 2011 and 2019.¹

The statute caps production and consumption at these percentages of the baseline:²

2020–2023: 90 percent (a 10 percent cut)
2024–2028: 60 percent (a 40 percent cut)
2029–2033: 30 percent (a 70 percent cut)
2034–2035: 20 percent (an 80 percent cut)
2036 and beyond: 15 percent (an 85 percent cut)

The country is in the 60 percent tier through 2028. As the cap tightens, the price of high-GWP refrigerants keeps climbing, which is the point of the design: the economics push buyers toward lower-GWP alternatives.

Why the pressure? Global warming potential compares how much heat one ton of a gas absorbs over 100 years relative to one ton of carbon dioxide.³ R-410A, the workhorse of residential air conditioning for two decades, carries a GWP of 2,088. One ton of it traps roughly as much heat as 2,088 tons of CO₂.

GWP Limits Already in Effect for New Equipment

The AIM Act also authorized the EPA to restrict which refrigerants can go into new products. The resulting Technology Transitions rule sets maximum GWP values by equipment category. Once a compliance date passes, manufacturers cannot produce, import, or sell equipment above the threshold, and contractors cannot install new systems that exceed it.⁴

Residential and light commercial AC and heat pumps: GWP limit of 700. Manufacture and import of higher-GWP systems banned since January 1, 2025; installation of new higher-GWP systems restricted as of January 1, 2026.
Household refrigerators and freezers: GWP limit of 150, effective January 1, 2025.
Stand-alone retail food refrigeration: GWP limit of 150, effective January 1, 2025.
Vending machines: GWP limit of 150, effective January 1, 2025.
Variable refrigerant flow (VRF) systems: GWP limit of 700, with installation compliance starting January 1, 2026.
Light-duty passenger vehicle AC: GWP limit of 150, starting with model year 2025.
Medium- and heavy-duty vehicle AC: GWP limit of 150, starting model year 2028.
Industrial process chillers operating above −30°C: GWP limit of 700, effective January 1, 2026.
Residential dehumidifiers: GWP limit of 700, effective January 1, 2025.

These restrictions apply to new products and new installations, not to existing equipment. If you own a system running R-410A or another high-GWP refrigerant, you can keep operating and repairing it using existing or reclaimed supplies. Nobody is going to force you to remove a working air conditioner. When it comes time to replace it, though, the new unit will use a different refrigerant.

Sell-Through Windows for Pre-Deadline Inventory

The transition does not happen overnight, and the EPA built sell-through windows into the rule so equipment made before a deadline is not stranded.

For residential and light commercial AC and heat pumps, an interim final rule extended the installation deadline to January 1, 2026, for equipment manufactured or imported before January 1, 2025.⁴ In October 2025, the EPA proposed removing the installation deadline entirely for that pre-2025 inventory, which would allow remaining R-410A systems to be installed without a fixed cutoff.⁵ That proposal was submitted for final interagency review in April 2026. Until it is finalized, the EPA has stated that enforcement of the current installation deadline is a low priority.

VRF systems follow a different timeline. Higher-GWP VRF equipment manufactured or imported before January 1, 2026, may be installed until January 1, 2027. Projects that received an approved building permit before October 5, 2023, have until January 1, 2028.⁶

What Is Replacing R-410A

The two refrigerants leading the residential transition are R-454B (GWP 466) and R-32 (GWP 675). Both sit under the 700 ceiling. R-454B has been adopted by several major manufacturers as their primary R-410A replacement in North America; R-32 is widely used in ductless mini-splits and dominates in many other countries.

Both carry an ASHRAE safety classification of A2L: low toxicity and mildly flammable, with a low burning velocity that makes ignition far less likely than with traditional flammable gases.⁷ Mild flammability is not zero flammability, and the shift triggered updates to equipment design and building codes.

Equipment designed for A2L refrigerants under UL 60335-2-40 includes factory-installed leak detection sensors that activate at less than 25 percent of the refrigerant’s lower flammability limit. When a leak is detected, the system automatically runs circulation fans to dilute the concentration. If the sensor fails, the fans run continuously as a fail-safe. Charge limits are tied to room size.

The 2024 editions of the International Building Code, International Residential Code, International Fire Code, and International Mechanical Code all permit A2L refrigerants in residential and commercial settings.⁸ If your local jurisdiction has not adopted the 2024 codes, your contractor may need to work through local amendments or variances before installing new A2L equipment.

Reclaimed Refrigerant Rules

As the allowance cap tightens and new high-GWP refrigerant grows scarcer, reclaimed refrigerant becomes essential for keeping older systems running. Two rules matter.

Since January 1, 2026, refrigerant sold as “reclaimed” cannot contain more than 15 percent virgin (newly produced) HFCs by weight. EPA-certified reclaimers must label every container to certify compliance and keep records for three years.⁹

Starting January 1, 2029, servicing or repairing equipment in three sectors must use reclaimed refrigerant rather than virgin product: supermarket systems, refrigerated transport, and automatic commercial ice makers. Reclaimers and distributors serving those sectors face annual reporting obligations beginning in 2027. If your operation depends on any of that equipment, lining up a reliable reclaimed-refrigerant supplier well before 2029 is the practical move.

The Venting Ban and Technician Certification

Intentionally releasing HFC refrigerants during service, repair, or disposal is illegal under Section 608 of the Clean Air Act.¹⁰ The prohibition covers both ozone-depleting substances and their HFC substitutes. Permitted releases are narrow: small de minimis amounts during good-faith connection or disconnection of service hoses, normal operational emissions such as slow leaks and mechanical purging during regular use, and a handful of exempt hydrocarbon substitutes the EPA has cleared, such as isobutane (R-600a) in household refrigerators and propane (R-290) in stand-alone retail food units.

Recovered refrigerant must be recycled on-site, returned to the equipment, or sent to an EPA-certified reclaimer.

Anyone who maintains, services, repairs, or disposes of refrigeration or air conditioning equipment that could release refrigerant must hold EPA Section 608 certification.¹¹ Four types exist:

Type I: small appliances such as window AC units and household refrigerators.
Type II: high-pressure or very-high-pressure systems, excluding small appliances and motor vehicle AC.
Type III: low-pressure systems, such as large centrifugal chillers.
Universal: all equipment types; requires a proctored core exam rather than an open-book version.

Section 608 credentials do not expire. Apprentices are exempt while a certified technician closely and continuously supervises their work. If you are hiring someone to work on your system, ask for proof of certification.

Penalties

The AIM Act uses the enforcement provisions of the Clean Air Act, so violations of the phase-down, equipment restrictions, venting ban, and certification rules all sit under the same penalty structure.² The statute sets a base civil penalty of $25,000 per day per violation, with annual inflation adjustments required by federal law.¹² The inflation-adjusted maximum civil penalty currently exceeds $121,000 per day per violation.¹³

Criminal prosecution is available for knowing violations, including illegal import or smuggling of HFCs without allowances and deliberate false reporting. Enforcement activity has grown as the tightening cap creates black-market incentives. For building owners and facility managers, the practical checklist is short: verify contractor certification, use approved refrigerants in new installations, keep records of every service call, and never let anyone vent refrigerant into the air.

1
U.S. Environmental Protection Agency. HFC Allowances
2
Office of the Law Revision Counsel. 42 USC 7675 – American Innovation and Manufacturing
3
U.S. Environmental Protection Agency. Understanding Global Warming Potentials
4
Environmental Protection Agency. Technology Transitions HFC Restrictions by Sector
5
Federal Register. Phasedown of Hydrofluorocarbons: Reconsideration of Certain Regulatory Requirements Promulgated Under the Technology Transitions Provisions of the American Innovation and Manufacturing Act of 2020
6
U.S. Environmental Protection Agency. Regulatory Actions for Technology Transitions
7
ASHRAE. UNEP/ASHRAE Refrigerant Fact Sheet 1 – Update on New Refrigerants Designations and Safety Classifications
8
International Code Council. A2L Refrigerants Transition
9
Environmental Protection Agency. American Innovation and Manufacturing Act: Reclamation Requirements for Hydrofluorocarbon Refrigerants
10
Environmental Protection Agency. Stationary Refrigeration – Prohibition on Venting Refrigerants
11
U.S. Environmental Protection Agency. Section 608 Technician Certification Requirements
12
GovInfo. 42 USC 7413 – Federal Enforcement
13
U.S. Environmental Protection Agency. Amendments to the EPAs Civil Penalty Policies to Account for Inflation