EPA 608 Leak Rate Thresholds & Evacuation Chart (2026)

In 2026, federal Clean Air Act enforcement penalties for improper refrigerant recovery or ignored appliance leaks reach up to $69,733 per day per violation under inflation-adjusted EPA schedules, while legacy exam question banks still test the $44,539 per day statutory figure (EPA Section 608 Enforcement, 2026). For HVAC/R technicians preparing for proctored certification exams or managing commercial mechanical rooms, two numerical tables govern almost every compliance decision: the annual leak rate trigger percentages and the mandatory recovery evacuation vacuum table.

Missing these numbers is the primary reason candidates fail the Type II and Type III sections of the EPA 608 Universal certification exam. Worse, 2026 marks a major regulatory milestone: under the American Innovation and Manufacturing (AIM) Act, the mandatory leak repair charge threshold dropped from 50 pounds down to 15 pounds for HFC and A2L appliances.

This reference guide answers the exact leak repair, verification test, and evacuation questions that appear on 2026 proctored exams. Pair this breakdown with our printable EPA 608 cheat sheet and active-recall EPA 608 flashcards to lock in every regulatory number before test day.

Starting in 2019, What Are the EPA 608 Leak Rate Thresholds?

Starting in 2019, the EPA lowered the mandatory annual leak rate thresholds to 10% for comfort cooling, 20% for commercial refrigeration, and 30% for industrial process refrigeration (IPR) under 40 CFR § 82.157 (eCFR 40 CFR § 82.157, 2026). These stricter triggers replaced the pre-2019 thresholds of 15% for comfort cooling and 35% for both commercial refrigeration and industrial process refrigeration.

Why do so many proctored exam questions begin with the exact phrase, "Starting in 2019, what is the leak rate threshold..."? When the EPA updated Section 608 under the 2016 Refrigerant Management Rule (which took full effect on January 1, 2019), certifying organizations added the year anchor to distinguish the current 10% / 20% / 30% limits from older 1990s textbook answers. Under the 2026 AIM Act Subsection (h) regulations (40 CFR § 84.106), the EPA kept these exact same 10%, 20%, and 30% annual trigger percentages.

Which Leak Repair Categories Does the EPA Define?

When an exam question asks "which leak repair category does the EPA define" for a specific piece of mechanical equipment, you must classify the system by its primary thermal purpose rather than its physical compressor style (EPA Compliance Guidance, 2026). The EPA defines three mutually exclusive leak repair categories:

Comfort Cooling Appliances (10% Threshold): Any air conditioning or heat pump appliance used to provide cooling and humidity control for human occupants in residential, office, institutional, hospitality, or commercial buildings. Examples include commercial rooftop package units (RTUs), split-system air conditioners, variable refrigerant flow (VRF) heat pumps, and centrifugal or screw chillers supplying chilled water to office air handlers.

Commercial Refrigeration Appliances (20% Threshold): Any refrigeration appliance used in the retail food, cold storage warehouse, hospitality, or beverage sectors to store, display, or preserve goods for sale or distribution. Examples include supermarket multiplex compressor racks, walk-in coolers and freezers, reach-in display cases, and commercial ice machines.

Industrial Process Refrigeration / IPR (30% Threshold): Complex, customized refrigeration equipment directly linked to an industrial, chemical, pharmaceutical, petrochemical, metallurgical, or food-manufacturing production line where temperature control is integral to manufacturing a product rather than storing finished goods.

What happens if a single chiller loop cools both an industrial manufacturing reactor and an adjacent office building? Under 40 CFR § 82.152, the EPA classifies a dual-purpose appliance as Industrial Process Refrigeration (30%) only if 50% or more of its total cooling capacity serves the industrial process. If less than 50% serves the process line, the entire system is regulated under the stricter Comfort Cooling (10%) threshold.

How Did the 2026 AIM Act Subsection (h) Rule Change the Appliance Charge Threshold?

Effective January 1, 2026, the EPA's AIM Act Subsection (h) rule (40 CFR Part 84, Subpart C) lowered the mandatory leak repair appliance charge threshold from 50 pounds down to 15 pounds for any system containing an HFC or substitute refrigerant with a Global Warming Potential (GWP) greater than 53 (eCFR 40 CFR Part 84, 2026). Legacy Section 608 (40 CFR § 82.157) retains the 50-pound threshold for ozone-depleting substances (CFCs and HCFCs like R-22 and R-123).

Here is how to answer charge-threshold questions on your exam and in the field in 2026:

1. If the question specifies an HFC or A2L substitute with GWP > 53 (or references the 2026 AIM Act rule): The mandatory leak repair, inspection, and recordkeeping rules apply at 15 pounds or more of full charge. This covers R-410A (GWP 2,088), R-134a (GWP 1,430), R-404A (GWP 3,922), R-407C (GWP 1,774), R-32 (GWP 675), and R-454B (GWP 466). For more on how R-454B and R-32 are regulated, see our R-410A vs R-454B transition guide.
2. If the question is from a traditional Section 608 exam bank or specifies an ODS refrigerant (R-22, R-123, R-11, R-12): Select 50 pounds or more (`50+ lbs`), which remains the statutory threshold printed in 40 CFR § 82.157 for ozone-depleting substances.
3. If the question asks about Automatic Leak Detection (ALD) systems in 2026: Under 40 CFR § 84.108, commercial refrigeration and industrial process refrigeration appliances containing 1,500 pounds or more of a refrigerant with GWP > 53 must be equipped with an Automatic Leak Detection system (effective January 1, 2026 for new installations, and January 1, 2027 for existing systems installed between 2017 and 2025).

How to Calculate the Leak Rate: Annualizing vs. Rolling Average

Every time a technician adds refrigerant to an appliance with a charge of 15+ lbs (GWP > 53) or 50+ lbs (ODS)—other than during a seasonal variance or initial installation—the owner or operator must calculate the appliance's leak rate (40 CFR § 82.157(b), 2026). The EPA permits two standardized mathematical formulas, and whichever method an owner selects must be used consistently across all appliances at that facility:

Method 1: The Annualizing Method projects the current refrigerant addition over a full 365-day year based on the number of days elapsed since the previous refrigerant addition (or 365 days if no refrigerant was added in the prior year). The formula is: `(Pounds of Refrigerant Added ÷ Pounds of Full Charge) × (365 ÷ Shorter of Days Since Last Addition or 365) × 100%`.

Method 2: The Rolling Average Method sums all refrigerant added to the appliance over the previous 365 days (including the current addition) and divides directly by the full system charge. The formula is: `(Total Pounds of Refrigerant Added in Past 365 Days ÷ Pounds of Full Charge) × 100%`.

For example, if a supermarket rack holds a 200-lb full charge of R-404A and a technician adds 25 lbs of refrigerant exactly 182.5 days (half a year) after the last top-off, the Rolling Average Method yields `25 ÷ 200 = 12.5%` (assuming no other additions in the past 365 days), whereas the Annualizing Method yields `(25 ÷ 200) × (365 ÷ 182.5) = 25%`, which exceeds the 20% Commercial Refrigeration trigger!

What Happens If an Initial or Follow-Up Leak Verification Test Fails?

Under 40 CFR § 82.157(e) and 40 CFR § 84.106(e), whenever an appliance exceeds its applicable leak rate threshold (10%, 20%, or 30%), the owner must repair the appliance within 30 days (or 120 days if an industrial process shutdown is required) and pass two separate leak verification tests: an initial verification test and a follow-up verification test (eCFR 40 CFR § 82.157, 2026).

Initial Verification Test vs. Follow-Up Verification Test Rules

The EPA strictly separates the timing and operating state of these two tests to prevent technicians from simply topping off a leaking system and walking away:

Initial Leak Verification Test: Must be performed immediately after repairs are completed and before any refrigerant is added back into the appliance (or before returning the appliance to normal operating characteristics). This test proves the brazed joint, flare, or gasket holds under a standing pressure or vacuum test.

Follow-Up Leak Verification Test: Must be performed within 10 days of the successful initial verification test, after the appliance has been recharged and returned to normal operating temperature, pressure, thermal expansion, and compressor vibration. If the appliance was never evacuated during the repair, the follow-up test can be conducted as soon as the system reaches normal operating characteristics, up to 10 days post-repair.

Step-by-Step Protocol When an Initial Leak Verification Test Failed

One of the highest-frequency questions on the proctored Type II and Type III exam asks: "An initial leak verification test failed—what must the technician or owner do next?"

Here are the exact legal rules when an initial leak verification test failed or a follow-up test fails:

1. Do NOT recharge or return the appliance to normal service: If an initial leak verification test failed, the repair is legally incomplete. You may not add regulated refrigerant or place the system back into normal operation until it passes an initial verification test.
2. Conduct additional repairs within the 30-day window: Technicians may perform as many additional repair attempts and repeat initial/follow-up verification tests as necessary, provided both verification tests pass before the 30-day repair deadline expires (or 120 days for an IPR shutdown).
3. What if a verification test fails AFTER the 30-day deadline?: If a follow-up verification test fails after the 30-day (or 120-day) repair window has expired, the owner or operator has 30 days from the date of the failed verification test to draft a written Retrofit or Retirement Plan and must execute that retrofit or retirement within 1 year (40 CFR § 82.157(f), 2026).

Mandatory Leak Inspections & The 125% Chronic Leaker Rule

Once an appliance exceeds its 10%, 20%, or 30% leak rate threshold, repairing the leak is not the end of the owner's obligation. The system must also undergo periodic proactive leak inspections for the next year (and continuously for larger charges) until the owner demonstrates the appliance has not exceeded its threshold for four consecutive quarters:

500+ lbs Full Charge: Mandatory leak inspections once every 3 months (quarterly) unless monitored by an approved Automatic Leak Detection (ALD) system.

50 to 499 lbs (ODS) / 15 to 499 lbs (HFCs & Substitutes with GWP > 53 as of Jan 1, 2026): Mandatory leak inspection once per calendar year (annually).

Chronic Leaker Reporting Rule (125% Threshold): If any regulated appliance leaks 125% or more of its full refrigerant charge in a single calendar year, the owner or operator must submit a written Chronic Leaker Report to the EPA by March 1 of the following year detailing the root cause of the leaks and the remediation steps taken (40 CFR § 82.157(j), 2026).

What Are the Required EPA 608 Evacuation Levels (40 CFR § 82.156 Table 1)?

Under 40 CFR § 82.156 Table 1, before opening any appliance for maintenance, service, repair, or disposal, a certified technician must evacuate the refrigerant to a mandatory vacuum depth based on four factors: the appliance type (Type I, II, or III), the refrigerant pressure classification, the full system charge (`< 200 lbs` vs. `≥ 200 lbs`), and whether the recovery equipment was manufactured before or on/after November 15, 1993 (eCFR 40 CFR § 82.156, 2026).

Many simplified study guides accidentally omit the distinction between HCFC-22 (R-22) and Other High-Pressure Refrigerants (R-410A, R-454B, R-32, R-134a, R-404A, R-12, R-500, R-502). On the proctored exam, confusing those two rows will cost you points. Use the complete statutory table below as your definitive reference:

Why Type II Separates HCFC-22 from R-410A, R-134a, and R-502

Notice how HCFC-22 (`< 200 lbs`) only requires recovery down to 0 in. Hg (`0 psig`) even with post-1993 equipment, whereas an identical `< 200 lb` appliance charged with R-134a, R-410A, R-454B, R-12, or R-502 must be pulled down to 10 in. Hg vacuum (40 CFR § 82.156 Table 1, 2026). Similarly, at 200 lbs or more (`≥ 200 lbs`) using post-1993 recovery equipment:

HCFC-22 (`≥ 200 lbs`) requires 10 inches of mercury (10 in. Hg) vacuum.

Other High-Pressure & Medium-Pressure refrigerants (`≥ 200 lbs`)—including R-134a, R-410A, R-404A, R-12, R-500, and R-502—require 15 inches of mercury (15 in. Hg) vacuum.

When answering a Type II evacuation question on our free EPA 608 practice test, always check three details in the question stem before clicking an answer: (1) Which specific refrigerant is inside the appliance? (2) Is the charge under 200 lbs or 200+ lbs? (3) Was the recovery machine manufactured before or after November 15, 1993?

Why Type III Low-Pressure Evacuation Changes Units (25 in. Hg Vacuum vs. 25 mm Hg Absolute)

On the Type III exam section, the EPA tests whether you understand the physical difference between gauge vacuum (`in. Hg vacuum`) and barometric-independent absolute pressure (`mm Hg absolute`):

Pre-November 15, 1993 Recovery Equipment: Must evacuate a low-pressure chiller to 25 inches of mercury vacuum (`25 in. Hg vacuum`), which is a relative gauge reading affected by local weather and altitude.

Post-November 15, 1993 Recovery Equipment: Must evacuate a low-pressure chiller to 25 millimeters of mercury absolute (`25 mm Hg absolute`), which equals approximately 29 in. Hg vacuum or 25,000 microns and is unaffected by barometric pressure changes.

Remember that while recovering refrigerant from a Type III water-cooled centrifugal chiller, you must circulate water through the chiller tubes (or use a hot-water heater loop) because boiling liquid R-123 or R-11 under a vacuum rapidly drops the vessel temperature below 32°F, which can freeze standing water and burst the internal copper tubes. Likewise, when recharging an evacuated Type III chiller, always introduce vapor refrigerant first until saturation pressure rises above the 32°F freeze point (~16.9 in. Hg vacuum for R-11 or ~20 in. Hg vacuum for R-123) before adding liquid refrigerant.

When Does the EPA Allow Evacuating to 0 PSIG Instead of Full Table 1 Vacuum?

Under 40 CFR § 82.156(a)(2), technicians are legally permitted to stop recovery at 0 psig (atmospheric pressure) instead of pulling the deep vacuum levels listed in Table 1 in only two specific field situations (eCFR 40 CFR § 82.156, 2026):

1. Leaking Appliances Where Vacuum Would Pull in Air or Water: If an appliance has a severe external leak or a ruptured water-cooled heat exchanger tube, pulling the system into a vacuum (`in. Hg` or `mm Hg`) would suck non-condensable air or liquid water directly into the recovery cylinder, contaminating the recovered refrigerant and prevents the machine from ever reaching the target vacuum. In this scenario, you may stop recovery at 0 psig.
2. Non-Major Repairs Not Followed by System Evacuation: If you isolate a section of a large appliance to perform a non-major repair (such as replacing a liquid-line filter-drier, solenoid coil, or sight glass) and the isolated section is not subsequently evacuated to the atmosphere, bringing the isolated section to 0 psig is permitted.

What counts as a Major Repair where full Table 1 evacuation is mandatory? Under 40 CFR § 82.152, the EPA defines a Major Repair as any maintenance, service, or repair that involves the removal or replacement of any of four core components:

The Compressor

The Condenser

The Evaporator

An Auxiliary Heat Exchanger

Wait a few minutes after reaching your required Table 1 recovery vacuum and watch the manifold gauge. If system pressure rises back above 0 psig, liquid refrigerant is still trapped in the compressor crankcase oil or isolated piping—meaning you must run the recovery machine again until the vacuum holds steady.

High-Yield EPA 608 Exam Practice Questions (Leak Rates & Evacuation)

Test your mastery of these 2026 rules with four representative exam questions modeled directly on proctored Section 608 test banks. For a complete 3-week study schedule covering all four sections, read our guide on how to pass the EPA 608 exam.

Question 1: Starting in 2019, what is the mandatory annual leak rate threshold that triggers repair requirements for a supermarket walk-in freezer rack?

A) 10%

B) 15%

C) 20%

D) 30%

Answer: C (20%). Supermarket racks, walk-in freezers, and cold storage systems fall under the Commercial Refrigeration category, which has a 20% annual leak rate threshold (lowered from 35% in 2019). Comfort cooling is 10%, and Industrial Process Refrigeration (IPR) is 30%.

Question 2: Effective January 1, 2026 under the AIM Act Subsection (h) rule (40 CFR Part 84), at what minimum refrigerant charge size do mandatory leak repair and inspection rules apply to appliances containing R-410A or R-454B?

A) 5 pounds

B) 15 pounds

C) 50 pounds

D) 200 pounds

Answer: B (15 pounds). As of January 1, 2026, 40 CFR § 84.106 lowered the leak repair appliance threshold from 50 lbs to 15 lbs for HFCs and substitutes with a GWP greater than 53 (which includes R-410A at GWP 2,088 and R-454B at GWP 466). Note that 50 lbs still applies to legacy ODS systems under 40 CFR Part 82.

Question 3: After repairing a leak on a regulated commercial refrigeration system, an initial leak verification test failed. What must the technician do?

A) Recharge the system immediately and perform the follow-up test within 10 days

B) Perform additional repairs and repeat the initial verification test before recharging or returning the system to normal operation

C) Evacuate the system to 25 mm Hg absolute and file a Chronic Leaker report within 48 hours

D) Draft a 1-year appliance retirement plan immediately after the first failed test

Answer: B. Under 40 CFR § 82.157(e), an appliance cannot be recharged or returned to normal operating characteristics until it passes an initial leak verification test. Technicians may perform additional repairs and re-tests as many times as needed within the 30-day repair window.

Question 4: Using recovery equipment manufactured after November 15, 1993, what is the required evacuation level for a high-pressure appliance containing 240 lbs of R-134a before performing a compressor replacement?

A) 0 psig

B) 4 inches of mercury vacuum

C) 10 inches of mercury vacuum

D) 15 inches of mercury vacuum

Answer: D (15 inches of mercury vacuum). Per 40 CFR § 82.156 Table 1, an appliance containing 200 lbs or more of an "Other High-Pressure or Medium-Pressure" refrigerant (such as R-134a, R-410A, R-404A, R-12, or R-502) requires evacuation to 15 in. Hg vacuum when using post-Nov 15, 1993 recovery equipment (whereas HCFC-22 at 200+ lbs requires 10 in. Hg).

Once you pass your exam and receive your credential, bookmark our EPA 608 certification lookup and replacement card guide so you always know how to verify your certification ID online, or review our offline EPA 608 iOS study guide to keep all 50 quick-reference evacuation and leak tables accessible in mechanical rooms without cell service.

Frequently Asked Questions

Starting in 2019, what is the leak rate threshold for comfort cooling, commercial refrigeration, and IPR?

Starting in 2019 and continuing in 2026 under 40 CFR Section 82.157 and 40 CFR Section 84.106, the mandatory annual leak rate thresholds are 10% for comfort cooling appliances, 20% for commercial refrigeration appliances, and 30% for industrial process refrigeration (IPR) systems. These replaced the pre-2019 rates of 15%, 35%, and 35%.

How did the January 1, 2026 AIM Act rule change the 50-lb leak repair requirement?

Effective January 1, 2026 under 40 CFR Section 84.106 (AIM Act Subsection h), the EPA lowered the mandatory leak repair charge threshold from 50 pounds down to 15 pounds for appliances containing HFCs or substitutes with a GWP above 53, including R-410A, R-454B, R-32, R-134a, and R-404A. Legacy ODS systems still use the 50-pound threshold.

What must a technician do if an initial leak verification test failed?

If an initial leak verification test failed, the technician must not add refrigerant or return the appliance to normal operating characteristics. Under 40 CFR Section 82.157(e), the technician must conduct additional repairs and repeat the initial verification test until it passes, followed by a follow-up verification test within 10 days, all within the 30-day repair window.

What is the EPA 608 evacuation level for a Type II system with 200+ lbs of R-22 versus R-410A?

Under 40 CFR Section 82.156 Table 1, when using recovery equipment built on or after November 15, 1993, an appliance containing 200 pounds or more of HCFC-22 (R-22) must be evacuated to 10 inches of mercury vacuum. An appliance containing 200 pounds or more of R-410A, R-134a, or R-502 requires 15 inches of mercury vacuum.

Why is Type III low-pressure evacuation measured in 25 mm Hg absolute instead of inches of mercury?

Recovery equipment manufactured on or after November 15, 1993 must evacuate Type III low-pressure chillers to 25 mm Hg absolute (25,000 microns) rather than the pre-1993 target of 25 in. Hg vacuum. Absolute pressure measurement eliminates errors caused by local barometric pressure fluctuations and altitude differences during deep vacuum recovery.

When does an industrial process refrigeration (IPR) system get 120 days instead of 30 days to repair a leak?

Under 40 CFR Section 82.157(d), the standard leak repair deadline is 30 days from discovering that an appliance exceeded its threshold. An industrial process refrigeration (IPR) system is granted an extended 120-day repair window only when an industrial process shutdown is required to access and repair the leaking component.

Summary & Next Steps for Exam Prep

Mastering the EPA 608 leak rate thresholds (`10%`, `20%`, `30%`), the January 1, 2026 AIM Act `15-lb` charge rule (alongside the `50-lb` legacy ODS rule), the 30-day/10-day verification workflow, and the 40 CFR § 82.156 Table 1 evacuation matrix guarantees you will not drop easy points on Type II or Type III exam questions.

Ready to test yourself under timed conditions? Drill all 21 exam subtopics with our free interactive EPA 608 flashcards, keep our one-page EPA 608 cheat sheet on your workbench, and explore long-term trade earnings in our HVAC technician career guide.

Regulatory Sources & Documentation

U.S. Code of Federal Regulations, 40 CFR § 82.156 — Proper Evacuation of Refrigerant from Appliances (Table 1), retrieved October 2026, https://www.ecfr.gov/current/title-40/part-82/section-82.156

U.S. Code of Federal Regulations, 40 CFR § 82.157 — Appliance Maintenance and Leak Repair, retrieved October 2026, https://www.ecfr.gov/current/title-40/part-82/section-82.157

U.S. Code of Federal Regulations, 40 CFR Part 84, Subpart C — Management of Regulated Substances (AIM Act Subsection h 15-lb Rule), retrieved October 2026, https://www.ecfr.gov/current/title-40/part-84

U.S. Environmental Protection Agency (EPA), Stationary Refrigeration Leak Repair Requirements, retrieved October 2026, https://www.epa.gov/section608/stationary-refrigeration-leak-repair-requirements