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EPA 608 Certification

EPA 608 Core — practice test

Core is the shared part of the EPA Section 608 test. Anyone who could be expected to open the refrigerant circuit of an appliance has to be certified, and every certification includes Core, whether the card says Type I, II, III or Universal. Pass Core plus a Type and you are certified for that Type. Pass Core and all three Types and you are Universal. People fail Core because they treat it as common sense. It is not. It asks for exact definitions, exact percentages and exact record rules, and one wrong word in a choice makes it a wrong answer.

Studying for EPA 608 Core? Overhaul Prep has 206 questions written to EPA's own topic list for this part. A second expert worked out each answer and read the regulation section it cites before it went live, and every explanation ends with that source, so you can look it up.

206E608C questions
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19,209questions in total
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What's on the EPA 608 Core test

Under Appendix D, every test has 25 Core questions (Group I). A Type I, II or III test adds 25 questions for that Type, and Universal is Core plus all three Types, 100 questions in all. The passing score is 70 percent on the closed-book tests, with no notes or training materials. Type I can also be given by mail-in, which needs 84 percent and cannot count toward Universal. EPA's topic list for Core covers environmental impacts, the Clean Air Act and Montreal Protocol, the Section 608 regulations, substitute refrigerants and oils, basic refrigeration, the three R's (recover, recycle, reclaim), recovery techniques, dehydration and evacuation, safety, and shipping. Time limits and fees are set by the certifying organization, not by the regulation, so ask yours.

EPA's test topics: Core

EPA publishes the topics each Section 608 certification test covers. This is EPA's list for Core, in EPA's words: its 10 areas and 40 topics. Every one of our 206 E608C questions ends with the regulation section or practice it rests on.

The real test, per 40 CFR 82 Subpart F, Appendix D: 25 questions from this part; 70 percent passes; closed book.

AEnvironmental Impacts7 topics
  • 1.Destruction of ozone by chlorine
  • 2.Presence of chlorine in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants
  • 3.Identification of CFC, HCFC, and hydrofluorocarbon (HFC) refrigerants (not chemical formulas, but idea that R-12 is a CFC, R-22 is an HCFC, R-134 is an HFC, etc.)
  • 4.Idea that CFCs have higher ozone-depletion potential (ODP) than HCFCs, which in turn have higher ODP than HFCs
  • 5.Understanding of the atmospheric effects from the types of refrigerants
  • 6.Health and environmental effects of stratospheric ozone depletion
  • 7.Evidence of stratospheric ozone depletion and role of CFCs and HCFCs
BClean Air Act and Montreal Protocol7 topics
  • 1.CFC phaseout date
  • 2.R-22 phaseout date
  • 3.Venting prohibition at servicing
  • 4.Venting prohibition at disposal
  • 5.Venting prohibition on substitute refrigerants
  • 6.Maximum penalty under the Clean Air Act
  • 7.Montreal Protocol (the international agreement to phase out production of ozone-depleting substances)
CSection 608 Regulations7 topics
  • 1.Definition/identification of high and low-pressure refrigerants
  • 2.Definition of system-dependent versus self-contained recovery/recycling equipment
  • 3.Identification of equipment covered by the rule (all air-conditioning and refrigeration equipment containing CFCs or HCFCs except motor vehicle air conditioners)
  • 4.Need for third-party certification of recycling and recovery equipment
  • 5.Standard for reclaimed refrigerant [Air Conditioning, Heating, and Refrigeration Institute (AHRI) Standard 700-2016]
  • 6.The sales restriction
  • 7.The Clean Air Act prohibition on venting
DSubstitute Refrigerants and oils3 topics
  • 1.Absence of "drop-in" replacements
  • 2.Incompatibility of substitute refrigerants with many lubricants used with CFC and HCFC refrigerants and incompatibility of CFC and HCFC refrigerants with many new lubricants (includes identification of lubricants for given refrigerants, such as esters with R-134; alkylbenzenes for HCFCs)
  • 3.Fractionation problem--tendency of different components of blends to leak at different rates
ERefrigeration3 topics
  • 1.Refrigerant states (vapor versus liquid) and pressures at different points of refrigeration cycle; how/when cooling occurs
  • 2.Refrigeration gauges (color codes, ranges of different types, proper use)
  • 3.Leak Detection
FThree R Definitions3 topics
  • 1.Recover
  • 2.Recycle
  • 3.Reclaim
GRecovery Techniques2 topics
  • 1.Need to avoid mixing refrigerants
  • 2.Factors affecting speed of recovery (ambient temperature, size of recycling or recovery equipment, hose length and diameter, etc.)
HDehydration Evacuation1 topic
  • 1.Need to evacuate system to eliminate air and moisture at the end of service
ISafety6 topics
  • 1.Risks of exposure to refrigerant (e.g., oxygen deprivation, cardiac effects, frost bite, long-term hazards)
  • 2.Personal protective equipment [gloves, goggles, self-contained breathing apparatus (SCBA)-in extreme cases, etc.]
  • 3.Reusable (or "recovery") cylinders versus disposable cylinders [ensure former Department of Transportation (DOT) approved, know former's yellow and gray color code, never refill latter]
  • 4.Risks of filling cylinders more than 80 percent full
  • 5.Use of nitrogen rather than oxygen or compressed air for leak detection
  • 6.Use of pressure regulator and relief valve with nitrogen
JShipping1 topic
  • 1.Labels required for refrigerant cylinders (refrigerant identification, DOT classification tag)

From EPA's Section 608 test topics, read October 20, 2026. All four 608 topic lists, and the test format in the regulation's words →

High-yield EPA 608 Core topics

The material that shows up year after year. If you're short on time, start here.

  • The venting prohibition covers anyone maintaining, servicing, repairing or disposing of an appliance. It covers CFCs, HCFCs and non-exempt substitutes, which includes HFCs like R-134a and R-410A. Only the listed exemptions are free to vent, such as nitrogen, carbon dioxide and water in any application, and knowingly releasing refrigerant after you recovered it is still a violation (40 CFR 82.154(a)).
  • Know the three R's cold. Recover is removing refrigerant in any condition and storing it in an external container, with no testing or processing needed. Recycle is cleaning it for reuse in equipment of the same owner, usually with oil separation and filter-driers. Reclaim is reprocessing to the Appendix A specification, based on AHRI Standard 700-2016, and proving it with the prescribed analysis (40 CFR 82.152).
  • Used refrigerant may be sold or offered for sale as a refrigerant only after a certified reclaimer has reclaimed it, with limited exceptions such as MVAC-only refrigerant and transfers inside a parent company and its subsidiaries. Refrigerant may go back into the appliance it came from, or another appliance owned by the same person, without being recycled or reclaimed. That return rule does not apply to MVACs or MVAC-like appliances (40 CFR 82.154(d), 82.156(h)).
  • Class I substances are listed in Appendix A of 40 CFR part 82 subpart A and include CFCs like R-12. Class II substances are in Appendix B and include HCFCs like R-22. R-22 is still class II, so the venting rule still applies to it, because the phaseout limits new production and does not loosen the handling rules (40 CFR 82.152, 82.154(a)).
  • Ozone depletion order: CFCs have the highest ODP, HCFCs are far lower (about 0.01 to 0.1), and HFCs are zero because they have no chlorine. Chlorine is the culprit: UV in the stratosphere frees it from the molecule, and one chlorine atom acts as a catalyst and destroys thousands of ozone molecules. HFCs are still regulated for global warming.
  • Recovery equipment made or imported for servicing must be certified by an approved equipment testing organization. Equipment for small appliances must be certified to recover 90 percent of the refrigerant with the test-stand compressor operating and 80 percent with it not operating. Self-contained equipment does the work without the appliance's components, and system-dependent equipment needs them (40 CFR 82.152, 82.158).

Where techs lose points on EPA 608 Core

Good technicians miss these — not from lack of skill, but because the question is built to catch them.

  • Wrong belief: HFCs do not hurt the ozone layer, so you can vent them. Right answer: HFC ODP is zero, but the venting prohibition covers non-exempt substitutes. R-410A and R-134a must be recovered.
  • Wrong belief: a small leftover amount, or venting outdoors, is fine. Right answer: a release counts as de minimis only when it comes from a good-faith attempt to recover or recycle, with the required practices followed and certified equipment used. A small quantity or a quick job does not make it legal.
  • Wrong belief: if I clean the used refrigerant with a filter-drier, I can sell it. Right answer: that is recycling. Selling used refrigerant to a new owner requires reclamation by a certified reclaimer.
  • Wrong belief: mixed refrigerants can be separated in the shop. Right answer: once two refrigerants are mixed you cannot separate them, and the mix has to go to a reclaimer or be destroyed. A leaking zeotropic blend loses its higher-pressure component first, so recover the rest and recharge by weight, and pull blends from the cylinder as liquid.

A study plan that works for EPA 608 Core

Roughly two weeks of real preparation, in the order that actually builds on itself.

  1. Day 1: Ozone and refrigerant families. Learn CFC, HCFC and HFC by example (R-12, R-22, R-134a), the ODP order, how chlorine destroys ozone, and the health effects of more ultraviolet reaching the surface.
  2. Day 2: Clean Air Act, Montreal Protocol and the venting rule. Learn who it covers, what is exempt, class I versus class II, the sales restriction, certificate revocation and the final processor's paperwork.
  3. Day 3: Section 608 definitions and the three R's. Drill recover, recycle, reclaim, the pressure classes of appliances, certified equipment, and the AIM Act limit on virgin refrigerant in reclaim.
  4. Day 4: Shop practice. Cover substitutes and oils, recovery and evacuation technique, safety (frostbite, oxygen displacement, nitrogen regulators) and shipping (DOT cylinders, never refill disposables). Then take a full practice set and review every miss.

Sample EPA 608 Core questions

Straight from the bank — answers highlighted, with the explanation underneath.

Which atom in a refrigerant molecule is responsible for destroying ozone in the stratosphere?

  1. Chlorine
  2. Hydrogen
  3. Carbon
  4. Fluorine
WhyChlorine released from CFC and HCFC molecules attacks ozone. Fluorine, hydrogen and carbon do not break ozone down this way. Source: general refrigeration practice.

Which international treaty set the schedule for phasing out production of ozone-depleting substances such as CFCs?

  1. The Kyoto Protocol
  2. The Geneva Convention
  3. The Montreal Protocol
  4. The Paris Agreement
WhyThe Montreal Protocol on Substances That Deplete the Ozone Layer is the international agreement controlling the phaseout of ozone-depleting substances. In the US the Clean Air Act, as amended in 1990, carries it out. Source: general refrigeration practice.

Under the Section 608 definitions, a low-pressure appliance uses a refrigerant whose liquid-phase saturation pressure at 104 degrees F is:

  1. between 170 and 355 psia
  2. between 45 and 170 psia
  3. below 45 psia
  4. above 355 psia
WhyEPA draws the lines at 104 F: under 45 psia is low pressure, 45 to 170 is medium, 170 to 355 is high, and over 355 is very high. Chillers using R-11 or R-123 are the classic low-pressure examples. Source: 40 CFR 82.152 (definitions of high-, medium-, low- and very high-pressure appliance).

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