Which EPA 608 certification type do you need?
The type you need depends on the equipment you touch, and the rule defines that by the refrigerant's pressure, not by whether the job feels big or small. Here is what each type covers, in the regulation's own terms.
Which certification do you need?
Tick everything you expect to work on. The answer comes straight from 40 CFR 82.161 and the equipment definitions in 82.152.
Worth knowing first: Small appliance status is decided first and overrides the pressure class. A household fridge uses R-134a, a medium-pressure refrigerant, but it is factory-sealed with 5 lb or less, so it is Type I rather than Type II.
Select at least one to see which certification the rule requires.
The four types
Type I: Small appliances
Persons who maintain, service, or repair small appliances must be certified as Type I technicians.
A small appliance is any appliance fully manufactured, charged, and hermetically sealed in a factory with five pounds or less of refrigerant.
Typically: Household and commercial refrigerators and freezers · Window, portable and packaged terminal air conditioners and heat pumps · Dehumidifiers · Under-the-counter ice makers · Vending machines · Drinking water coolers · Medical and industrial research refrigeration
This is the only type with a mail-in testing option, and the only one where the passing score is different: 84 percent for the mail-in format rather than 70.
Type II: Medium, high and very high-pressure appliances
Persons who maintain, service, repair, or dispose of medium-, high-, or very high-pressure appliances (except small appliances, MVACs, and MVAC-like appliances) must be certified as Type II technicians.
Covers three of the four pressure classes: medium (45 to 170 psia at 104 °F), high (170 to 355 psia), and very high (above 355 psia, or a critical temperature below 104 °F).
Typically: Residential split systems and heat pumps (R-410A, R-22) · Commercial rooftop units · Supermarket and cold storage refrigeration · Process refrigeration · Ultra-low-temperature and cascade systems (R-23, R-508)
Commonly called "the high-pressure one," which undersells it. R-134a is a medium-pressure refrigerant and medium-pressure appliances are Type II as well.
Type III: Low-pressure appliances
Persons who maintain, service, repair, or dispose of low-pressure appliances must be certified as Type III technicians.
A low-pressure appliance uses a refrigerant with a liquid phase saturation pressure below 45 psia at 104 °F.
Typically: Centrifugal chillers using R-11, R-123 or R-245fa · Large building and campus chiller plants
The smallest population of technicians, and the systems run in a vacuum, which is why the evacuation and leak-detection material differs from the other types.
Universal: All of the above
Persons who maintain, service, repair, or dispose of all appliances described in paragraph (a)(1)(i) through (iii) of this section must be certified as Universal technicians.
Type I, Type II and Type III together.
Typically: Anyone who wants to work on anything without checking first
The core test must be taken proctored to attain Universal certification, so an open-book take-at-home core will not get you there.
The pressure classes that decide it
Type II versus Type III is not a judgement call. The regulation sorts appliances by the refrigerant's liquid phase saturation pressure at 104 °F, and the class determines the type.
| Class | Rule | Example refrigerants | Type |
|---|---|---|---|
| Low-pressure | Liquid phase saturation pressure below 45 psia at 104 °F. | R-11, R-123, R-113, R-245fa | Type III |
| Medium-pressure | Liquid phase saturation pressure between 45 psia and 170 psia at 104 °F. | R-114, R-124, R-12, R-134a, R-500 | Type II |
| High-pressure | Liquid phase saturation pressure between 170 psia and 355 psia at 104 °F. | R-22, R-407A, R-407C, R-410A, R-502 | Type II |
| Very high-pressure | Critical temperature below 104 °F, or liquid phase saturation pressure above 355 psia at 104 °F. | R-13, R-23, R-503, R-508A, R-508B | Type II |
Note where R-134a lands. It is a medium-pressure refrigerant, and Type II covers medium, high and very high. Calling Type II "the high-pressure one" is shorthand that leaves out a third of what it authorises.
The trap: pressure class is not the first question
Small appliance status is decided first and overrides the pressure class. A household fridge uses R-134a, a medium-pressure refrigerant, but it is factory-sealed with 5 lb or less, so it is Type I rather than Type II.
So the order matters. Ask first whether the unit was fully manufactured, charged and hermetically sealed in a factory with five pounds or less of refrigerant. If yes, it is a small appliance and Type I covers it, whatever refrigerant is inside. Only if the answer is no does the pressure class decide between Type II and Type III. Any table that maps refrigerants straight to certification types will get household refrigerators, vending machines and window units wrong.
What is not covered by 608 at all
Car and light truck air conditioning is regulated under Section 609, a different rule with its own certification. A 608 card does not authorise that work, and a 609 card does not authorise 608 work. They are separate credentials with separate exams.
Sources
Certification types and the equipment each authorises: 40 CFR 82.161. Equipment and pressure-class definitions: 40 CFR 82.152. Test structure and passing scores: 40 CFR Part 82, Subpart F, Appendix D. Verified against the live text on 2026-08-15.
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How to actually get certified, step by step · where to take the exam · free practice exam