How to use these EPA 608 study guides
Each study guide below matches one EPA 608 exam section. They are sourced from regulatory text, not from other study guides, so you study the exact facts certifying organizations test on, not interpretations or opinions.
Recommended study order: Core first, then Type II, then Type I, then Type III if you are pursuing Universal.
Core establishes the legal framework all type specific content builds on. Skip Core and jump to Type II, and you will struggle with regulation based questions because the underlying law is unfamiliar. Type II comes second because it covers the broadest real world equipment (split systems, walk in coolers, rooftop units). Type I is simpler: the 5 pound rule and the 80 percent and 90 percent thresholds are its main content. Type III comes last because vacuum operation and low pressure physics are counterintuitive to most technicians.
Study pace by experience level
Field technicians: 4 to 8 hours of focused study per section.
Apprentices and those new to HVAC: 8 to 16 hours per section.
EPA 608 Core section study guide
Core is mandatory for all EPA 608 types. It covers Clean Air Act Section 608 law, venting prohibition dates, civil penalties, and the recovery, recycling, and reclamation distinction.
Read the full Core study guide to master these facts. The four critical Core facts:
Venting prohibition dates. July 1, 1992 (CFCs and HCFCs). November 15, 1995 (HFCs). Both dates appear on the exam. Know which date applies to which refrigerant class.
Civil penalty. More than $44,539 per day per knowing violation under 40 CFR Part 82.166. This exact number is tested.
De minimis exemption. 0.1 ounce or less of refrigerant is the only quantity based exception to the recovery obligation. Anything above 0.1 oz requires recovery.
Recovery vs recycling vs reclamation. Recovery means removed and stored in a cylinder. Recycling means cleaned on site using filter driers and oil separation (does NOT meet ARI 700). Reclamation means reprocessed to ARI 700 purity at a certified facility and is required before resale.
EPA 608 Type I study guide
Type I covers small appliances of 5 pounds or smaller. Examples include window AC units, portable dehumidifiers, and small commercial units.
Read the full Type I study guide to understand recovery procedures and system requirements.
Type I recovery thresholds. When the compressor is running, recover 90 percent of the refrigerant. When the compressor is off, recover 80 percent. These are the two most tested numbers in Type I.
The 5 pound rule misunderstood. The 5 pound limit applies to the original manufactured charge, not the current charge in the system. Technicians commonly assume it means systems currently holding 5 pounds. It does not. A system originally charged with 4.8 pounds is still Type I even if it now holds 3 pounds from leaks.
Disposable cylinder prohibition. You cannot transfer refrigerant from a Type I system into a disposable cylinder. Only approved recovery cylinders or the appliance itself can hold recovered Type I refrigerant.
EPA 608 Type II study guide
Type II has the highest fail rate of all four sections. It covers high pressure systems: split systems, heat pumps, rooftop units, walk in coolers.
Read the full Type II study guide for detailed recovery procedures and equipment specific rules.
Type II leak rate tiers. Equipment falls into three categories. Comfort cooling systems (residential AC, heat pumps): 10 percent leak rate. Commercial refrigeration: 20 percent leak rate. Industrial process: 35 percent leak rate. If a system exceeds its tier threshold, you must repair it before using it again.
Vacuum recovery standards. For systems under 200 pounds of refrigerant, recover to 10 inches of mercury below atmospheric pressure. For systems 200 pounds and over, recover to 15 inches Hg. These are tested frequently and often appear as distractor questions.
A2L refrigerants now on the exam. Most candidates who fail Type II did so because they memorized R-22 data and skipped A2L refrigerants, including the AIM Act HFC phasedown regulations that have been added to current exam question sets. R-454B and R-455A are replacing R-410A under the AIM Act. R-22 production ended in 2020. Study sheets that focus only on R-22 will leave gaps on test day.
EPA 608 Type III study guide
Type III covers low pressure centrifugal chillers. These are large capacity systems that operate below atmospheric pressure.
Read the full Type III study guide to understand vacuum operation and low pressure physics.
Recovery vacuum standard. Equipment manufactured after November 15, 1993 requires recovery to 25 mm Hg absolute pressure. This is the deepest vacuum requirement across all four sections.
Air enters the system during a leak. This is the counterintuitive part. High pressure systems (Type II) lose refrigerant when they leak. Low pressure systems operate below atmospheric pressure, so leaks bring air and moisture in. That is why purge units exist: to remove non condensable gases before running the system again.
Leak test with dry nitrogen only. Never use refrigerant to pressure test a Type III chiller. Use dry nitrogen only, at pressures below 60 psig, to avoid explosion risk.
EPA 608 Universal study guide
Universal combines all four sections into one 100 question exam. You answer 25 Core questions, then 25 Type I, then 25 Type II, then 25 Type III.
Each of the four sections is scored independently. You need 18 of 25 (72 percent) in every section to earn Universal, so a weak section can fail the whole exam even if your overall total looks fine. The Core section also has to be taken proctored: an open book Core cannot count toward Universal.
Read the full Universal study guide for integrated content covering all four sections.
Most employers require Universal. Field technicians generally pursue Universal certification because it qualifies them to service all equipment types. If you are in an apprenticeship or early career role, Universal is the standard certification.
Night before study strategy
I recommend spending 30 minutes the night before your exam drilling your weakest section only. For a full prep plan from week one, read how to study for EPA 608.
Reviewing complete study guides the night before increases anxiety without improving scores. Instead, take a timed 30 question drill on whichever section tripped you up most in practice. This reinforces weak spots and builds confidence in your strongest areas.
30 minute night before drill checklist: Core dates (July 1, 1992 and November 15, 1995). Type I recovery thresholds (90 percent running, 80 percent off). Type II vacuum levels (10 in Hg under 200 lbs, 15 in Hg over 200 lbs). Type III vacuum (25 mm Hg absolute). Leak rates by Type II category (10 percent, 20 percent, 35 percent). De minimis threshold (0.1 oz). Civil penalty amount ($44,539/day). Passing score per section (18 of 25, which is 72 percent).
After working through the guides, test yourself on the EPA 608 practice test or drill the bank of 569 verified EPA 608 practice questions across all four sections, free with an account.
EPA 608 study guides frequently asked questions
The full EPA 608 study guide library
Core section
Clean Air Act, venting prohibition, civil penalties, recovery, recycling, and reclamation.
Type I
Small appliances, 5 pound rule, 80 percent and 90 percent recovery thresholds, process stubs.
Type II
High pressure systems, three tier leak rates, vacuum requirements, A2L transition.
Type III
Low pressure chillers, 25 mm Hg recovery, purge units, freezing risk.
Universal
All four sections combined. Core, Type I, Type II, and Type III in one exam.
Cheat sheet
One page reference: dates, thresholds, refrigerant classes, key numbers.
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