EPA 608 Cheat Sheet: Key Numbers and the Rules Behind Them

This unofficial EPA 608 cheat sheet puts key numbers and rules on one page, and each number sits next to the condition that makes it true. It's a U.S. study reference, not a test-day aid: Type II, Type III, and Universal tests are closed book; Type I-only programs may offer an open-book route.

The numbers people mix up most

Sources: 40 CFR 82 Subpart F, Appendix D (§e); §82.152; §82.156; §82.157; 40 CFR 84.106; 40 CFR 19.4, Table 1; EPA Test Topics. See also §82.154(c)(3), §82.155(c), and Appion cylinder-safety bulletin (PDF).

Recovery levels: pick the right row first

Appliances other than small appliances, MVACs, and MVAC-like appliances

MVAC means motor vehicle air conditioning; MVAC-like equipment includes certain off-road vehicle A/C systems. The date columns refer to when the recovery or recycling machine was manufactured or imported, not the appliance. Values are inches of mercury (in. Hg) vacuum relative to standard atmospheric pressure of 29.9 in. Hg, except the low-pressure row. Use the appliance's full charge (or the full charge of the applicable isolated component you're opening); recover the liquid refrigerant as well as reaching the listed level.

Source: 40 CFR 82.156(a), Table 1.

Read it in three steps: find the refrigerant's pressure class, then the charge size, then the machine's date. Two boundaries trip people up:

• Exactly 200 lb goes in the "200 lb or more" row.
• R-134a is medium-pressure, not high-pressure. With recovery equipment manufactured or imported on or after Nov 15, 1993, a 250-lb R-134a system goes to 15 in. Hg, not 10.

A reading of 0 in. Hg isn't a vacuum at all. It's atmospheric pressure (0 psig), and it doesn't mean the system is empty.

When the full table level isn't required

A major repair removes the compressor, condenser, evaporator, or an auxiliary heat exchange coil. Leaving an opening of more than 4 square inches of flow area for more than 15 minutes also counts.

Sources: §82.156(a)(1)–(2); §82.152, "major maintenance, service, or repair".

Small appliances (Type I)

Or evacuate the small appliance to 4 in. Hg vacuum. That's an alternative route, not an extra step after reaching the percentage.

Source: §82.156(b).

Core

Dates

Sources: 42 U.S.C. 7671g(c) (venting dates; the substitutes date is "5 years after November 15, 1990"); EPA Class I phaseout; EPA Class II phaseout; §82.154(c); §82.161; §84.106(a)(4); UNEP, Montreal Protocol adoption.

Refrigerant families

The ranking to remember is CFC > HCFC > HFC. CFCs are stable enough to reach the stratosphere, where strong UV light breaks them apart and frees chlorine. That chlorine destroys ozone, the layer that screens out harmful UV.

Zero ODP doesn't mean harmless or unregulated. Many HFCs have a high global warming potential (GWP), and venting them is still illegal.

Sources: EPA Test Topics, Core → Environmental Impacts; EPA basic ozone-layer science; EPA Class II phaseout, HCFC/HFC distinction.

Pressure classes

EPA classifies an appliance by its refrigerant's liquid saturation pressure at 104°F.

\At standard atmospheric pressure, subtract 14.7 from psia to get psig; at another ambient pressure, use that ambient pressure instead. ESCO Institute's 2026 pressure-temperature chart prints these rounded psig boundaries.*

Sources: §82.152, pressure-class definitions; ESCO 2026 PT chart (PDF).

Recover, recycle, reclaim

You may put recovered refrigerant back into the same appliance, or another appliance owned by the same person, without recycling or reclaiming it (motor vehicle A/C and MVAC-like appliances excepted).

Sources: §82.152; §82.156(h); §82.154(d).

Venting: what's allowed

• Never knowingly vent a CFC, HCFC, or non-exempt substitute such as an HFC, whether it's still in the system or already recovered.
• EPA permits only three kinds of release:

1. Tiny (de minimis) amounts lost during good-faith recovery done by the rules, such as connecting and disconnecting hoses.
2. Losses during normal operation, such as leaks and mechanical purging. Leak-repair rules still apply to larger systems.
3. Refrigerants EPA has exempted.

• Exempt in any application: carbon dioxide, nitrogen, water.
• Exempt only in certain uses: ammonia in commercial or industrial process refrigeration and absorption units; propane (R-290), isobutane (R-600a), and R-441A in listed equipment such as household refrigerators and stand-alone retail cases. Check the exact end use before assuming a hydrocarbon is exempt.
• Nitrogen trace gas: you can't add nitrogen to a fully charged system and then vent the mix. Recover the charge first. Calling a refrigerant–nitrogen mixture a "trace gas" does not create a general venting exemption.

Sources: §82.154(a); EPA venting prohibition page.

Who can buy refrigerant

• A Section 608-certified technician, or an employer that proves to the seller it employs one.
• A Section 609 (motor vehicle A/C) technician may buy only refrigerant acceptable for motor vehicle A/C.
• One exception: non-exempt substitute refrigerant for motor vehicle A/C in containers designed for 2 lb or less, with a unique fitting and, if manufactured or imported on or after Jan 1, 2018, a self-sealing valve. The rule also lists resale, manufacturer, and other exceptions.

Source: §82.154(c).

Safety, cylinders, and shop basics

Sources: EPA Test Topics, Core → Safety, Shipping, Refrigeration, Substitute Refrigerants and Oils; Appion G5Twin manual, pp. 3, 6, 14–15 (PDF); Appion cylinder-safety bulletin (PDF); Hudson R-22 safety data sheet, §§2, 4–8, 14 (PDF); Mainstream R-410A manual, pp. 32–36 (PDF).

The refrigeration cycle in four parts

The system doesn't make cold. It moves heat out of one space and dumps it somewhere else.

Sources: Danfoss, how the refrigeration cycle works; EPA Test Topics, Core → Refrigeration.

Certification basics

• Types: Type I covers small appliances. Type II covers medium-, high-, and very high-pressure appliances, apart from the separate small-appliance and motor-vehicle categories. Type III covers low-pressure appliances. Universal covers all three. Every Type also requires passing Core.
• No expiration. Keep a copy of your certificate at your place of business until three years after you stop working as a technician.
• Apprentices may work without a card only while closely and continually supervised by a certified technician. They must be registered with the U.S. Department of Labor's Office of Apprenticeship (or a recognized state council), and apprentice status lasts at most two years.
• Penalties: besides the civil penalty of up to $124,426 per day per violation under the provision and dates above, EPA can revoke or suspend certification.

Sources: EPA certification requirements; §82.161(a); §82.152, "apprentice"; 40 CFR 19.4.

Type I: small appliances

Sources: §82.152, small appliance and retrofit definitions; §82.154(e); §82.155; EPA Test Topics, Type 1; Hudson R-22 safety data sheet, §§5–6 (PDF) (heat/decomposition hazards).

Type II: medium-, high-, and very high-pressure

Sources: §82.156(e), (g); EPA Test Topics, Type 2; Mainstream R-410A manual, pp. 35–36 (PDF); Appion G5Twin manual, pp. 6, 9, 14–15 (PDF); Hudson R-22 safety data sheet, §§5–8 (PDF); EPA SNAP, residential/light-commercial A/C listings.

Type III: low-pressure chillers

Much of a low-pressure chiller runs below atmospheric pressure, so leaks in those areas pull air and moisture in instead of pushing refrigerant out. That one fact explains most of Type III. The service reminders below are for study, not a complete chiller operating procedure.

Sources: §82.156(a)(1)(ii), Table 1; EPA Test Topics, Type 3; Trane PRGD-SVX01F-EN, p. 7, purge-system overview (manufacturer document hosted by ManualsLib); ESCO 2026 PT chart, p. 1 (PDF) (R-123 B1 classification).

Leak repair: two rulebooks since January 1, 2026

Before you use any leak percentage, identify three things: the refrigerant, the full charge, and what the equipment does.

Sources: 40 CFR 82.157 (a), (c)(2), (d)–(h), (j), (l); 40 CFR 84.106 (a), (c)–(h), (j), (l); EPA leak-repair fact sheet, January 2026 (PDF).

A refrigerant blend can require checking both frameworks; the columns are not necessarily mutually exclusive. Qualifying automatic leak-detection systems can replace some periodic inspections under each rule's conditions. The 2026 panel is current regulatory context, not a claim about every certifying program's exam content.

Two quick notes:

• EPA proposed on May 26, 2026 to exempt road and intermodal container transport refrigeration units from 84.106. As of September 28, 2026, the cited action is a proposal, and the current §84.106 text still includes refrigerated transport (Federal Register).
• Section 82.156(i) still shows the old 35%/15% leak rules, but its own text says it ended in 2019. Don't memorize it as current.

Worked example: the annualizing leak-rate formula

Leak rate (%) = (lb added ÷ full charge) ÷ (days since the last addition ÷ 365) × 100 If more than 365 days have passed, use 365. Use pounds added to return the appliance to full charge, including multiple additions related to the same leak; the full charge and elapsed days must be positive.

A 60-lb R-22 rooftop unit cools an office. A tech adds 3 lb, 91 days after the last addition.

(3 ÷ 60) ÷ (91 ÷ 365) × 100 = 20.054945…% ≈ 20.1%

R-22 is ozone-depleting, the charge is 50 lb or more, and office cooling is comfort cooling, so the trigger is 10%. At 20.1%, the owner must repair within 30 days or make a retrofit or retirement plan.

EPA also allows a second method, the rolling average: total the pounds added over the past 365 days—or since the last successful follow-up test showing all identified leaks were repaired, if that period is shorter—divide by the full charge, and multiply by 100. A facility has to use the same method for all of its appliances.

Part 84 first-calculation rule: for the first annualizing calculation after January 1, 2026, substitute 365 days for days since the last addition. For the first rolling calculation, count pounds added since January 1, 2026. Do not apply the ordinary 91-day example above to that first Part 84 calculation. The chronic-leaker report uses a calendar year, not this rolling 365-day window.

Sources: §82.152, “leak rate”; §84.106(b)(1)–(2), first calculations.

Numbers you'll still see, and how to read them

If your certifying program's own study material uses an older figure, that reflects when it was printed. The regulation is the current authority. For how your program words its questions, use its current manual.

Check yourself: 16 questions

Cover the answer, commit to one, then check. Each answer explains the rule behind it. If you miss one, reread that section, then retest tomorrow rather than five minutes from now.

These are original, unofficial self-checks built from the sheet above. They aren't real exam questions, and your score here doesn't predict your exam result.

Before exam day

Check which exam version you're taking. ESCO Institute, one of EPA's approved certifying programs, released an updated Section 608 test bank in August 2026. Its 2018 exam remains available until January 1, 2027. ESCO publishes a separate manual and pressure-temperature chart for each version. Ask your testing program which version you'll take, and study with the chart that matches it. Other approved programs set their own schedules. (ESCO EPA 608 exam resources)

Leave this sheet at home. Type II, Type III, and Universal tests are closed book and proctored, and proctors must make sure no notes are used. Some programs offer a mail-in or open-book Type I test. That program's rules decide what materials you can use. Open-book Core credit cannot be used for Universal, and Appendix D says mail-in Type I tests do not count toward Universal. (Appendix D §a–b; EPA certification requirements)

Know what the card covers. Universal means all three Section 608 Types. It isn't a state contractor license, and it isn't Section 609 certification for motor vehicle A/C. (EPA: Section 608 and 609 overlap)

Next step: revisit the section behind any answer you could not explain without looking. To arrange an exam, use EPA’s list of approved certifying programs; the chosen program can confirm its version and permitted references.

Quick answers

Is there a PDF? You can use your browser's print command and choose "Save as PDF." Check the preview for all tables, answers, and sources before saving; this page does not require a separate download.

Does this cover R-410A, R-454B, and other newer refrigerants? The Section 608 rules here apply to non-exempt substitutes, including HFCs such as R-410A. EPA's public test-topic list doesn't name A2L refrigerants, but ESCO’s 2026 chart includes A2L refrigerants such as R-454B. A2L is a flammability classification, not permission to use any recovery machine. For handling, follow the refrigerant and equipment manufacturer's instructions and the codes that apply to your job.

Does Section 608 certification expire? No. EPA says Section 608 credentials don't expire.

Related free Castleport guides: EPA 608 exam prep, evacuation requirements, and leak repair requirements.

Sources

Last verified September 28, 2026: the cited recovery, certification, leak-repair, reporting, sales, disposal, and penalty provisions; EPA's published study reminders; ESCO's exam-version notice and chart; and the linked technical references. The eCFR pages displayed Title 40 as current through September 24, 2026. The 16 self-check answers and worked arithmetic were checked against those sources and stated inputs.

This resource was developed with AI assistance. Source checking is not credentialed subject-matter review. See our editorial standards.

EPA and federal rules

• EPA, Section 608 Test Topics, Technician Certification Requirements, and approved certifying programs
• EPA, Prohibition on Venting Refrigerants and Section 608 and Section 609 Overlap
• EPA, Phaseout of Class I and Class II ozone-depleting substances; basic ozone-layer science
• 40 CFR Part 82, Subpart F: §82.152, §82.154, §82.155, §82.156, §82.157, §82.161, Appendix D
• 40 CFR 84.106; EPA's January 2026 leak-repair fact sheet (PDF); the May 26, 2026 proposed transport-refrigeration exemption
• 40 CFR 19.4, Table 1 (42 U.S.C. 7413(b) penalty row) and 42 U.S.C. 7671g(c) (venting dates)
• EPA, SNAP residential/light-commercial A/C listings; UNEP, Montreal Protocol adoption

Exam versions and charts

• ESCO Institute, EPA Section 608 exam resources and 2026 PT chart (PDF)
• Mainstream Engineering, Section 608 exam format and passing-score explanation

Technical explanations

• Appion, G5Twin instruction manual (PDF) and refrigerant-container safety bulletin (PDF)
• Hudson Technologies, R-22 safety data sheet (PDF)
• Mainstream Engineering, R-410A manual, technical recovery and lubricant explanations (PDF)
• Danfoss, how the refrigeration cycle works
• Trane, PRGD-SVX01F-EN, p. 7, purge-system overview (manufacturer document hosted by ManualsLib)

Castleport Test Prep Editorial Team. Castleport Test Prep is an independent exam prep publisher. We're not affiliated with, endorsed by, or approved by the U.S. Environmental Protection Agency, ESCO Institute, Mainstream Engineering, or any Section 608 certifying program, and EPA doesn't review or approve prep materials. Exam and credential names are used for identification; trademarks belong to their respective owners. This sheet is study guidance, not legal or compliance advice. The current regulations and your certifying program's written terms control. Found an error? Tell us.