20 EPA 608 Sample Questions to Test Yourself
These 20 EPA 608 sample questions were written by 608Prep from EPA’s own published test topics for the Section 608 Technician Certification exam, five questions per section: Core, Type I, Type II, and Type III. They’re original questions built to test the same concepts the real exam covers, not copies of any certifying organization’s actual test bank, which none of us have access to and none is publicly published.
(608Prep is not affiliated with the EPA or any certifying organization. These questions are our own, written against EPA’s public test topics page, not reproduced from any exam.)
Answer each one before checking the explanation underneath. If you miss more than one or two per section, that section needs more review time before you book the real test, since the actual exam only gives you 25 questions per section and requires 70% correct (18 of 25) if proctored, or 84% (21 of 25) for an open-book Core or Type I attempt.
Core section (ozone science, regulations, safety, recovery)
1. Which refrigerant class has an ozone depletion potential of zero because it contains no chlorine or bromine? A) CFCs B) HCFCs C) HFCs D) Halons
Answer: C, HFCs. HFCs contain hydrogen, fluorine, and carbon only, no chlorine or bromine, so they don’t break down stratospheric ozone the way CFCs and HCFCs do.
2. Under the Clean Air Act, intentionally releasing refrigerant to the atmosphere during service or disposal is: A) Allowed for appliances under 5 pounds B) Prohibited regardless of refrigerant type C) Allowed only for CFCs being phased out D) Allowed with a state permit
Answer: B. The venting prohibition applies to all covered refrigerants, ozone-depleting or substitute, with no small-appliance exception.
3. Recovery cylinders approved for reuse under DOT rules are traditionally identified by which color code? A) Red top, white body B) Yellow top, gray body C) Blue top, silver body D) Green top, black body
Answer: B. Reusable DOT-approved recovery cylinders use a yellow-top, gray-body scheme; disposable cylinders should never be refilled regardless of color.
4. Filling a refrigerant recovery cylinder beyond what percentage of its rated capacity creates a serious overfill hazard? A) 60% B) 80% C) 95% D) 100%
Answer: B. Refrigerant expands with temperature, so cylinders filled past 80% capacity have too little vapor space and can rupture as pressure builds.
5. For leak detection, which gas is recommended over oxygen or compressed air to pressurize a system? A) Nitrogen B) Argon C) Carbon dioxide D) Propane
Answer: A. Nitrogen is inert and won’t support combustion. Oxygen or compressed air introduces both an explosion risk and moisture into the system.
Type I, small appliances (fridges, window units, vending machines)
6. Under EPA’s rule, a “small appliance” is defined as equipment that: A) Weighs less than 50 pounds B) Contains 5 pounds or less of refrigerant and is manufactured, charged, and hermetically sealed at the factory C) Is portable D) Uses only R-410A
Answer: B. The 5-pound, factory-sealed definition is what separates small appliances (refrigerators, window units, vending machines) from other equipment classes.
7. What is the correct recovery method for a small appliance with an inoperative (non-working) compressor? A) Vent to atmosphere, since the compressor can’t assist B) A system-dependent “passive” recovery device paired with a vacuum pump C) Wait for the compressor to restart D) No recovery is required if the compressor doesn’t run
Answer: B. A passive recovery device combined with a vacuum pump and a non-pressurized recovery container is the standard method when the compressor itself can’t be used to help recover refrigerant.
8. When recovering refrigerant from a small appliance with an inoperative compressor, a technician should install: A) Only a low-side access valve B) Only a high-side access valve C) Both high-side and low-side access valves D) No access valve is needed
Answer: C. Both access points are required so refrigerant can be recovered from the full system, not just one side of it.
9. R-134a is the common substitute refrigerant for which older CFC in small appliances? A) R-22 B) R-12 C) R-410A D) R-404A
Answer: B. R-134a (an HFC) replaced R-12 (a CFC) in most small hermetic appliances as the ozone-depleting refrigerant was phased out.
10. After completing service on a small appliance, a technician should generally: A) Leave solderless access fittings in place for future service B) Remove solderless access fittings C) Weld a new permanent port regardless D) Overcharge the system slightly
Answer: B. Solderless fittings are meant to be temporary service points and should come off once the job’s done, since they’re a common leak source if left on.
Type II, high-pressure systems (split AC, most heat pumps)
11. Which appliances fall under Section 608’s leak repair threshold as “other” (non-comfort-cooling) equipment? A) Any appliance with a compressor B) Appliances containing 50 pounds or more of refrigerant C) Appliances under 5 pounds D) Only industrial equipment
Answer: B. EPA’s leak repair requirements kick in for appliances holding 50 pounds or more of refrigerant; exact allowable leak rates vary by equipment category, so check the current rule for your appliance type.
12. Before charging or recharging a high-pressure system, a technician should first: A) Leak test the system B) Pull an immediate deep vacuum without testing C) Add oil D) Vent old refrigerant from the lines
Answer: A. Leak testing before charging catches problems before refrigerant, and money, goes into a system that won’t hold it.
13. Which leak-test approach is preferred for high-pressure systems? A) Nitrogen alone B) Pure refrigerant C) Compressed shop air D) Pure oxygen
Answer: A. Nitrogen alone is the top choice; nitrogen with a trace amount of tracer refrigerant is an acceptable second option. Shop air introduces moisture, and oxygen is a serious explosion hazard, never use it for leak testing.
14. After reaching the required recovery vacuum on a high-pressure appliance, a technician should: A) Disconnect immediately B) Wait a few minutes to check whether pressure rises again C) Add nitrogen to the system D) Discard the recovery cylinder
Answer: B. A pressure rise after reaching vacuum usually means liquid refrigerant is still boiling off somewhere in the system or the oil, so the recovery isn’t actually finished.
15. System-dependent (“passive”) recovery equipment is prohibited on systems containing more than how much refrigerant? A) 5 pounds B) 15 pounds C) 50 pounds D) 200 pounds
Answer: B. Above 15 pounds, passive recovery methods aren’t allowed, active recovery/recycling equipment is required instead.
Type III, low-pressure systems (large chillers)
16. Which leak-test pressurization method is preferred first for low-pressure systems? A) Hot water method or a built-in heating/pressurization device B) Nitrogen C) Compressed air D) Pure oxygen
Answer: A. The hot water method or an equivalent built-in heating device ranks above nitrogen as the preferred pressurization method for low-pressure equipment specifically.
17. Before removing oil from a low-pressure chiller, a technician should heat it to approximately what temperature to minimize refrigerant release? A) 90°F B) 130°F C) 180°F D) 250°F
Answer: B. Heating the oil to roughly 130°F drives off dissolved refrigerant before the oil is removed, cutting emissions.
18. When recharging a centrifugal chiller, which phase of refrigerant should be introduced first? A) Liquid B) Vapor C) A 50/50 mix D) Whichever is more convenient
Answer: B. Vapor goes in first to prevent water inside the tubes from freezing; liquid refrigerant introduced too fast can drop tube temperature too quickly.
19. What is the purpose of a purge unit on a low-pressure system? A) To remove air and moisture that leak into the system under vacuum B) To add refrigerant automatically C) To measure superheat D) To lubricate the compressor
Answer: A. Low-pressure systems commonly run below atmospheric pressure, so air and moisture (non-condensables) leak in over time; the purge unit removes them.
20. Under ASHRAE Standard 15, equipment rooms housing low-pressure chillers that use R-123 require what safety device? A) A carbon monoxide detector B) A refrigerant (oxygen deprivation) sensor C) A smoke detector only D) No special device is required
Answer: B. R-123 equipment rooms need a refrigerant sensor under ASHRAE Standard 15, since a leak in an enclosed space can displace breathable oxygen before anyone notices a smell.
Quick answer key
| # | Answer | # | Answer | # | Answer | # | Answer |
|---|---|---|---|---|---|---|---|
| 1 | C | 6 | B | 11 | B | 16 | A |
| 2 | B | 7 | B | 12 | A | 17 | B |
| 3 | B | 8 | C | 13 | A | 18 | B |
| 4 | B | 9 | B | 14 | B | 19 | A |
| 5 | A | 10 | B | 15 | B | 20 | B |
What does missing several questions in one section actually mean?
It usually points to a gap in one topic area, not the whole section. Someone who missed questions 11, 13, and 15 above is weak on Type II leak procedures specifically, not on high-pressure refrigeration overall, so the fix is targeted review of leak testing and recovery equipment limits, not rereading the entire Type II chapter from scratch. That’s the value of working through sample questions by section instead of one long mixed quiz: you can see exactly where the weak spot is.
Run 608Prep’s free practice quiz for a full-length, timed version of this same section-by-section format, with a larger question pool than these 20. If you want the reasoning behind every answer explained in plain language before you hit the real exam, the 608Prep study guide walks through Core, Type I, Type II, and Type III one at a time.
FAQ
Are these the actual questions on the EPA 608 exam? No. These are original questions 608Prep wrote from EPA’s published test topics to test the same knowledge areas. No certifying organization publishes its actual exam questions, so any sample-question set online, including ours, is written to mirror the topics, not to reproduce real test content.
How many questions does each real EPA 608 section have? 25 questions per section (Core, Type I, Type II, Type III), or 100 total across all four for Universal certification, per EPA’s certification requirements.
What score counts as passing? 70% correct (18 of 25) for a proctored section. Core and Type I can also be taken open-book at a required 84% (21 of 25), but that result won’t count toward Universal certification.
Which section do people usually struggle with most? Type III (low-pressure/chillers) and Type II (high-pressure) tend to trip people up more than Core or Type I, mainly because the leak repair thresholds, recovery sequencing, and equipment-room safety rules are more procedural and less intuitive than the ozone-science material in Core.
Do I need to memorize exact pressure-temperature numbers? You need to know how to read a pressure-temperature chart and apply it, not memorize specific psig values for every refrigerant. The real exam tests understanding of the relationship, not recall of a lookup table.
Bottom line: if you cleared most of these 20 without guessing, you’re in reasonable shape; if a specific section gave you trouble, review that section’s test topics directly rather than retaking a mixed quiz that hides where the gap actually is.