Common 608 Mistakes and Trick Questions

608 questions are rarely hard because the rule is complicated. They are hard because two answers look right and one word decides it. Below are ten traps that catch people, each with an original example question and the rule that settles it. None of these are real exam questions: real tests are drawn from a question bank EPA releases only to approved certifying organizations (40 CFR 82.161).

1. "Type II means high pressure only"

EPA's pages call Type II "high-pressure," but 40 CFR 82.161 makes Type II cover medium-, high- and very high-pressure appliances, except small appliances and motor vehicle systems.

2. Right number, wrong unit

Every row of the evacuation table is in inches of Hg vacuum, except low-pressure, which is 25 mm Hg absolute (40 CFR 82.156, Table 1). Inches of vacuum count down from atmospheric pressure; mm Hg absolute counts up from a perfect vacuum.

3. Forgetting which date matters

November 15, 1993 splits the evacuation table and the small appliance percentages. It refers to when the recovery or recycling equipment was manufactured or imported, not the appliance being serviced.

4. Missing the 200 lb split

For high- and medium-pressure appliances, the table changes at a full charge of 200 lb. A high-pressure appliance under 200 lb is 0 inches in both columns; at 200 lb or more it is 4 or 10.

5. Treating recycle and reclaim as the same

Recycled refrigerant is for equipment of the same owner. Used refrigerant sold for use as a refrigerant must first be reclaimed by a certified reclaimer (40 CFR 82.152 and 82.154(d)). Recovered refrigerant may go back into the same appliance, or another appliance of the same owner, without either (82.156(h)).

6. Applying leak repair to everything

The 82.157 leak repair rules apply to appliances with 50 lb or more of a class I or class II refrigerant. Since April 10, 2020 they do not apply to appliances containing only substitute refrigerants (EPA regulatory updates).

7. Mixing up the leak rates

Commercial refrigeration 20, industrial process refrigeration 30, comfort cooling and other appliances 10 percent (40 CFR 82.157(c)). A helpful order: the more a system is tied to an industrial process, the higher the allowed rate before repair; comfort cooling has the lowest.

8. Reading "de minimis" as "a little venting is fine"

De minimis releases are allowed only when they happen during good-faith attempts to recapture and recycle refrigerant while following the required practices, such as connecting and disconnecting hoses (40 CFR 82.154(a)(2)). Knowingly venting a small amount on purpose is still venting.

9. Assuming every Type I result counts toward Universal

A mail-in Type I test has an 84 percent passing score and cannot be used toward Universal (Appendix D to Subpart F). EPA also says Core taken as an open-book exam cannot be used for Universal (certification requirements).

10. Getting the card facts backwards

Three facts that tests and coworkers get wrong:

• EPA does not issue certification cards. Your certifying organization does, within 30 days of the test (Appendix D, section (f)).
• Section 608 credentials do not expire (EPA certification requirements).
• You keep a copy of your certificate at your place of business, until three years after you stop working as a technician (40 CFR 82.161).

Bonus trap: the small appliance definition

Five pounds or less is only half of it. A small appliance must also be fully manufactured, charged and hermetically sealed in a factory (40 CFR 82.152). A field-charged unit with a small charge is not a small appliance.

How to beat these traps

• Underline the one word that changes the answer: medium, absolute, same owner, mail-in, factory.
• Ask which rule the question is testing before you look at the options.
• Check units every time.

Practice on the free 12-question quiz, then read the guide for your weakest section. The exam structure guide explains the format and scoring.

Frequently asked questions

What is the most common 608 trap?

Assuming Type II means only high pressure. 40 CFR 82.161 makes Type II cover medium-, high- and very high-pressure appliances, so R-134a equipment is Type II.

Is 25 mm Hg the same as 25 inches of vacuum?

No. Low-pressure appliances must reach 25 mm Hg absolute. The other rows of the evacuation table are in inches of Hg vacuum, relative to 29.9 inches.

Does EPA issue 608 cards?

No. EPA says it does not issue certification cards. Your certifying organization issues the wallet card, within 30 days of the test per Appendix D.

Are these the real exam questions?

No. Every example here is original. Real tests are drawn from a question bank that is released only to approved certifying organizations.