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United States · Certification test

EPA Section 608 certification study guide

The Environmental Protection Agency (EPA) doesn’t publish a study guide. It posts the topics each section of the test covers, and the rules themselves are in Title 40 of the Code of Federal Regulations (CFR), Part 82, Subpart F. Approved programs such as ESCO Institute, Mainstream Engineering and the Air Conditioning Contractors of America (ACCA) offer manuals, and EPA doesn’t review or approve any of them, so any EPA Section 608 certification study guide you buy is that program’s own take on EPA’s topics.

  • NoneStudy guide published by EPA
  • December 5, 2025Last update to EPA’s test topics page
  • Not reviewed by EPAProgram manuals and prep courses
Where to study

Updated October 2026 · Written from official sources, listed at the bottom of this page

What the regulation says each section must ask

Appendix D to Subpart F sets the subject areas. Core questions come from three:

  • The environmental impact of CFCs (chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons) and substitute refrigerants
  • Laws and regulations
  • The changing industry outlook

Each type section asks about five areas for that kind of equipment: leak detection, recovery techniques, safety, shipping and disposal.

What should an EPA Section 608 certification study guide cover for Core?

EPA’s test topics page breaks Core into these areas:

  • Environmental impacts: how chlorine destroys ozone, telling CFC, HCFC and HFC (hydrofluorocarbon) refrigerants apart, and why CFCs deplete more ozone than HCFCs, and HCFCs more than HFCs
  • The Clean Air Act and Montreal Protocol: the CFC and R-22 phaseout dates, the venting bans at service, at disposal and for substitutes, and the maximum Clean Air Act penalty
  • Section 608 rules: high- and low-pressure refrigerants, system-dependent and self-contained recovery equipment, the equipment covered, third-party certification of recovery equipment, the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) 700‑2016 standard for reclaimed refrigerant and the sales restriction
  • Substitute refrigerants and oils: why there are no drop-in replacements, which lubricants go with which refrigerants, and fractionation in blends
  • Refrigeration: refrigerant states and pressures around the cycle, gauge color codes and ranges, and leak detection
  • The three Rs: recover, recycle and reclaim
  • Recovery techniques, and evacuating to remove air and moisture at the end of service
  • Safety: exposure risks, protective equipment, recovery versus disposable cylinders, the 80 percent fill limit, and nitrogen with a regulator for leak testing
  • Shipping: cylinder labels with the refrigerant name and the Department of Transportation (DOT) classification tag
Type I topics: small appliances →Type II topics: high-pressure equipment →Type III topics: low-pressure equipment →

Manuals and courses from approved programs

  • ESCO Institute: EPA’s list notes a training manual.
  • Mainstream Engineering: manuals for open-book Type I (in English and Spanish) and Section 609, and free Type I training software with practice exams.
  • ACCA: a Technicians Guide and Workbook for the 608 test, and a self-paced online prep course.
  • EPA also says some programs have guides made for people who haven’t taken a test in a long time.

Two rules keep this material apart from the test. A program’s training has to be completely separate from giving the test, and the training that comes with a mail-in Type I test can’t include sample questions that copy the test’s wording.

Free EPA 608 practice tests and courses →

Rules newer than the test topics

EPA’s test topics page was last updated December 5, 2025, and it describes the Part 82 leak repair rules for ozone-depleting refrigerants. Since January 1, 2026, the American Innovation and Manufacturing (AIM) Act rules in 40 CFR Part 84 also set leak repair duties for HFC systems with 15 pounds or more of refrigerant, apart from home and light commercial air conditioning, and more dates follow from 2027. EPA suggests checking its Stationary Refrigeration pages for regulatory updates while you study.

HFC leak repair rules on the Type II page →
Sources: EPA · eCFR · Mainstream Engineering and 4 more. Checked October 2026.

Rules and fees can change, so check the official site before your test.

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