📋 EPA Leak Rate Thresholds: 10% / 20% / 30% — Section 608 Exam Answers (2019 & 2026 Rules)

If you learned refrigerant compliance under the old Section 608 rules, the 50-pound threshold you memorized stopped being the whole story on January 1, 2026. The EPA's AIM Act regulations (40 CFR Part 84, Subpart C) pulled the leak-repair threshold down to 15 pounds of full charge for HFC systems, and a surprising amount of the reference material floating around the internet, including several popular leak-rate calculators, still shows only the old number. The 50-pound line did not go away: it still governs the ozone-depleting refrigerants under 40 CFR Part 82, which is where an R-22 system is still handled today.

This article lays out the current rules as written in the regulation itself: who is covered, the exact trigger rates, and the deadlines that follow a failed leak test.

What Changed on January 1, 2026?

The applicability threshold dropped from 50 pounds to 15 pounds of full charge, for appliances containing an HFC refrigerant or substitute with a global warming potential greater than 53. That covers the refrigerants doing most of the work in the field today — R-410A, R-404A, R-134a, R-407C, R-448A, R-449A and friends.

The practical effect is enormous: common 5- to 10-ton rooftop units, larger split systems, and mid-size refrigeration racks that never triggered federal leak-repair requirements before are now squarely inside the program. If you maintain equipment in that range, leak-rate math is now part of your job.

The New Trigger Rates: 10 / 20 / 30

Under 40 CFR 84.106(c)(2), a leak inspection-and-repair obligation triggers when the annualized leak rate exceeds:

• ▸ 10% for comfort cooling appliances, refrigerated transport, and other refrigerant-containing appliances — this is the tier your rooftop units and split systems fall into.
• ▸ 20% for commercial refrigeration appliances — walk-ins, reach-ins, supermarket racks, ice machines.
• ▸ 30% for industrial process refrigeration (IPR).

The Deadlines After a Failed Test

When an appliance over 15 pounds exceeds its trigger rate, the owner or operator must locate and repair the leaks within 30 days of the refrigerant addition that revealed the leak — or 120 days where an industrial process shutdown is required. Longer extensions do exist under 84.106(f) for specific situations, including a needed component being genuinely unavailable, but they are conditional and documented, not something to plan around.

The part most people miss is that repairing it is not the end of it. The rule requires an initial verification test within that same 30 days (120 with a shutdown), showing the repair actually held, and then a follow-up verification test within 10 days of the successful initial test — or within 10 days of the appliance getting back to normal operating conditions, whichever applies. A repair with no verification on record is an incomplete job as far as the regulation is concerned.

There is also a chronic-leaker provision: appliances of 15 pounds or more that leak 125% or more of their full charge in a calendar year must be reported to the EPA by March 1 of the following year. For anything that leaked that badly during 2026, the first report is due March 1, 2027. That is the kind of paperwork obligation that sneaks up on portfolios without good refrigerant logs.

Whose Job Is the Leak-Rate Math?

This one causes real confusion, and it is worth being precise about. The regulation puts the obligation on the owner or operator of the appliance — they are the ones who must determine the leak rate, repair inside the deadline, and hold the verification records. The repairs themselves must be carried out by a certified technician.

So a technician saying "I don't calculate leak rate, that's an office job" is describing their own role accurately. In large supermarket and industrial accounts, the tech logs the charge and the customer's refrigerant-management system does the math. Nobody is standing on a roof with a calculator.

The catch is that this only works if such a system exists. Plenty of independent contractors, smaller commercial accounts and property managers now have equipment inside the 15-pound line and nothing running the calculation at all — the charge gets written on a ticket and the leak rate is never worked out by anyone. That is the gap the threshold change opened up, and it is the situation worth checking if you own or manage the equipment rather than just service it.

It matters on site for one practical reason: the 30-day clock starts when the exceedance happens, not when somebody gets around to the arithmetic. Knowing the number before you leave tells you whether a repair-and-verification deadline just started running.

Who Is Exempt?

The rule carves out residential and light-commercial air conditioning and heat pump systems from the leak-repair provisions. The line between a covered comfort-cooling appliance and an exempt light-commercial system is not always obvious in the field, so the conservative move — and the one we take in our own software — is to track the leak rate on everything at 15 pounds or more and note where the exemption may apply. Over-tracking costs you a log entry; under-tracking can cost a violation.

How the Annualized Math Works

The method the EPA accepts is the annualizing formula: leak rate = (pounds added ÷ full charge) × (365 ÷ days since the last addition) × 100.

Worked example: a 50-pound commercial refrigeration rack gets 5 pounds added, 180 days after the last charge. That is (5 ÷ 50) × (365 ÷ 180) × 100 = 20.3% annualized. Under the old rules of thumb that number sailed by; under 84.106 it exceeds the 20% commercial trigger and starts the 30-day repair clock. The same 20.3% on an IPR system would be fine — and on a rooftop unit it would be double the 10% trigger.

Don't Trust Old Charts

Search results are still full of 608-era tables showing 15%, 20%, 35%, or a flat 50-pound threshold. Before you rely on any chart or calculator, check it against the regulation text — the current numbers are in 40 CFR 84.106, and the EPA publishes a plain-language fact sheet on the leak-repair provisions.

Our free EPA leak-rate calculator was rebuilt against the 2026 rule and applies the 10/20/30 tiers automatically, including the 15-pound applicability gate. Equipment Tracker Pro also runs the same math on every refrigerant log entry in the app and flags threshold exceedances the moment you record a charge, so violations surface on the roof — not in an audit.

EPA 608 Exam Practice: Leak Rate Questions Answered

A steady stream of readers land on this page while studying for the EPA 608 certification exam, so here are direct answers to the leak-rate questions that show up on practice tests — the correct choice first, then why. One thing to keep straight while you study: the 608 exam tests the Section 608 rules written for ozone-depleting refrigerants, where the applicability line is 50 pounds of full charge, while day-to-day compliance on HFC systems now follows the 2026 AIM Act rule (40 CFR 84.106) covered above, with its 15-pound line. The trigger percentages, helpfully, are the same 10/20/30 under both.

When servicing a small appliance found to be leaking, is repair mandatory? Not mandatory, but recommended. Small appliances — units containing under 5 pounds of refrigerant charge — sit below every leak-repair applicability threshold, old rule or new. The mandatory locate-and-repair program applies to appliances of 50 pounds or more under the Section 608 rules the exam tests, and 15 pounds or more under the 2026 AIM Act rule for HFCs. Fixing the leak is good practice and good business; it just isn't a federal repair mandate at that size.

Starting in 2019, at what leak rate must industrial process refrigeration be repaired? 30%. The 2019 update to the Section 608 rules set the industrial process refrigeration (IPR) trigger at a 30% annualized leak rate for appliances holding 50 or more pounds of ozone-depleting refrigerant. The 30% IPR tier carried into the 2026 AIM Act rules unchanged — it now applies to HFC systems of 15 pounds or more as well.

A comfort cooling system with 50+ lbs of R-410A is leaking — what is the maximum allowable annual leak rate starting in 2019? 10%. Comfort cooling is the strictest tier, and 10% is the number the exam is looking for. It is also still the right number in the field today: R-410A is an HFC with a GWP well above 53, so under the 2026 AIM Act rule a comfort cooling appliance holding 15 or more pounds of it triggers mandatory repair when the annualized leak rate exceeds 10%.

At what annual leak rate must commercial refrigeration leaks be repaired? It depends on the vintage of your study material — and the answer choices are the giveaway. The current threshold is 20%, set by the 2019 Section 608 update and carried into the 2026 AIM Act rules. If 20% isn't among the options — as in the common 10/15/25/35 version of this question — you are looking at a pre-2019 question bank, and the expected answer is 35%, the historical commercial threshold. On any current exam that offers 20%, choose 20%.

What charge size do the EPA's leak repair requirements apply to? 50 or more pounds on the Section 608 exam; 15 or more pounds under the 2026 rule. Since January 1, 2026, the AIM Act rule (40 CFR 84.106) applies leak repair to appliances holding 15 or more pounds of an HFC refrigerant with a GWP above 53. Know both numbers: one passes the test, the other keeps your buildings out of trouble.

Starting in 2019, what is the leak rate threshold for comfort cooling appliances with 50+ lbs of an HCFC refrigerant? 10%. The 2019 Section 608 update lowered the comfort cooling threshold from the historical 15% to 10% for appliances with 50 or more pounds of HCFC or other ozone-depleting refrigerant. That 10% comfort-cooling tier is unchanged under the 2026 AIM Act rules.

The pattern worth memorizing: the tiers climb 10 → 20 → 30 as the equipment gets more industrial — 10% comfort cooling, 20% commercial refrigeration, 30% IPR. And if you want to check the math on a real system rather than a test question, our free leak-rate calculator applies the current tiers and the 15-pound gate automatically, and Equipment Tracker Pro runs the same check on every refrigerant log entry the moment you record a charge.

What is the EPA 15 lb refrigerant rule?

As of January 1, 2026, EPA leak-repair requirements under the AIM Act (40 CFR 84.106) apply to appliances with a full charge of 15 or more pounds of an HFC refrigerant with a GWP above 53 — down from the old 50-pound threshold.

What are the EPA leak rate thresholds in 2026?

10% for comfort cooling and other appliances, 20% for commercial refrigeration, and 30% for industrial process refrigeration, applied to appliances with 15+ pounds of charge.

How is the annualized leak rate calculated?

Leak rate = (pounds added ÷ full charge) × (365 ÷ days since last addition) × 100. Adding 5 lbs to a 50 lb system 180 days after the last charge is a 20.3% annualized rate.

How long do I have to repair a leak that exceeds the threshold?

Leaks must be located and repaired within 30 days of the refrigerant addition — or 120 days if repairs require an industrial process shutdown.

Are residential AC systems exempt from the 2026 leak rule?

Residential and light-commercial air conditioning and heat pump systems are carved out of the leak-repair provisions. When classification is unclear, the safe practice is to track leak rates anyway and note that the exemption may apply.

A comfort cooling system with 50 pounds or more of R-410A is leaking — what is the maximum allowable annual leak rate?

10%. Comfort cooling is the 10% tier — the answer the EPA 608 exam expects for the 'starting in 2019' version of this question, and still the threshold today under the 2026 AIM Act rules, which cover R-410A systems of 15 or more pounds.

What charge size do the EPA's leak repair requirements apply to?

On the Section 608 exam: appliances with 50 or more pounds of full charge. In the field since January 1, 2026: 15 or more pounds of an HFC refrigerant with a GWP above 53, under 40 CFR 84.106.

At what annual leak rate must commercial refrigeration leaks be repaired?

20%, under both the 2019 Section 608 update and the current 2026 AIM Act rules. Pre-2019 exam questions that don't offer 20% as a choice expect 35%, the historical commercial threshold.

Jonathan Curtis

HVAC Technician & Founder · Equipment Tracker Pro

Jonathan Curtis is an HVAC technician and the founder of Equipment Tracker Pro. He built the app to solve real-world property handoff challenges — including the absolute nightmare of losing years of maintenance histories and having to reprint physical asset tags.