AIM Act 2026: The HFC Leak Repair Rules for HVAC Techs

Rules as of October 20, 2026. EPA has said it will revisit parts of its HFC rules, so check the sources below before relying on a date for compliance.

The short version

• Covered: appliances with a full charge of 15 lbs or more of a refrigerant that contains an HFC, or an HFC substitute, with a GWP above 53.
• Exempt: residential and light commercial air conditioning and heat pumps.
• Repair when the annual leak rate passes 30% (industrial process refrigeration), 20% (commercial refrigeration) or 10% (comfort cooling and everything else).
• Ozone-depleting refrigerants such as R-22 and R-123 keep the older Section 608 rule: 50 lbs or more, same percentages.

Where the rule comes from

The AIM Act (2020) has EPA phase down HFC production and consumption to 15% of the historic baseline by 2036, and lets it set rules to cut HFC leaks and boost reclamation. EPA used that power in the Emissions Reduction and Reclamation (ER&R) rule, published October 11, 2024 (89 FR 82682) and codified in 40 CFR Part 84, Subpart C. Its leak repair requirements apply from January 1, 2026.

HFCs had been under Section 608 leak repair once before: a 2016 rule extended it to them, and EPA rescinded that extension in 2020. Since April 10, 2020, 40 CFR 82.157 covers only CFC and HCFC appliances. The ER&R rule brings HFCs back under a separate part of the regulations, with a 15-lb threshold instead of 50.

Which appliances and which thresholds

Swipe the table sideways to see every column.

Check the composition, not just the name: many newer blends mix HFCs with HFOs, and the GWP of the whole refrigerant decides whether the rule applies. Residential and light commercial AC and heat pumps are left out of the leak repair provisions.

How the leak rate is calculated

The leak rate is calculated every time refrigerant is added, unless the charge follows a retrofit, a new installation or a seasonal variance. Owners pick one method and stick with it. The annualizing method:

(lbs added ÷ full charge) × (365 ÷ days since the last addition) × 100

Example: a 1,000-lb system takes 50 lbs, 73 days after the previous addition. (50 ÷ 1,000) × (365 ÷ 73) × 100 = 25% a year, over the 20% trigger for commercial refrigeration. For the first calculation after January 1, 2026, the rule counts 365 days since the last addition.

When a system is over the threshold

The steps follow the long-standing ozone-depleting refrigerant rule: repair the leaks within 30 days, then confirm the repair with an initial verification test and a follow-up verification test once the system is back to normal operation. If a repair isn't practical, the owner can commit to a plan to retrofit or retire the appliance. Owners keep the records, service, leak inspections and verification tests, for three years. Extensions and the exact deadlines are in 40 CFR 84.106.

Automatic leak detection on big systems

Commercial refrigeration and industrial process refrigeration appliances with a full charge of 1,500 lbs or more also need an automatic leak detection system (40 CFR 84.108): sensors that alarm on leaked refrigerant in the air, or monitoring that flags a loss of 50 lbs or 10% of the charge, whichever is less. Systems installed from 2026 need it from the start; existing systems installed since January 1, 2017 have until January 1, 2027. Comfort cooling is not covered by this part.

Reclaimed refrigerant from 2029

Starting January 1, 2029, servicing certain existing equipment, including supermarket systems, refrigerated transport and automatic commercial ice makers, must use reclaimed HFCs rather than virgin product. Recovering refrigerant carefully, and sending it to a reclaimer, is what keeps that supply going.

What's still moving

In May 2026, EPA proposed taking road and intermodal container transport refrigeration units out of the leak repair requirements, and said it would reconsider other parts of its HFC rules, leak management included. Check the Federal Register for anything finalized since; we'll update this guide when the rules change.

What it means for the EPA 608 exam

Expect the thresholds, the 15-lb and 50-lb applicability, and how to calculate a leak rate. The Core exam guide covers the rest of the regulations section, and the EPA 608 Exam Prep app has AIM Act questions in Core, Type II and Type III.