EPA 608 Practice Test: Core, Type I, II, III
This is a free 15-question EPA Section 608 sampler, written by the StudyPDF team. It covers all four parts of the exam: Core, Type I for small appliances, Type II for high-pressure systems and Type III for low-pressure chillers, so it works as a warm-up for a single type or for Universal. Answer all 15 questions, then check your score and read the explanation for every question.
Which element, released when CFC molecules break apart in the stratosphere, destroys ozone?
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All 15 questions at a glance
Prefer to read before you play? Every question in the sampler is listed below. Answers and explanations stay collapsed until you open them.
1. Which element, released when CFC molecules break apart in the stratosphere, destroys ozone?
- A. Nitrogen
- B. Chlorine
- C. Carbon
- D. Hydrogen
Show answer and explanation
Answer: B. Chlorine
Ultraviolet light breaks CFC molecules apart high in the atmosphere and frees chlorine atoms. One chlorine atom can destroy thousands of ozone molecules because it is not used up in the reaction, which is why even small releases matter and why the Montreal Protocol targeted chlorine-containing refrigerants first.
2. Which list ranks refrigerant types from the highest to the lowest ozone depletion potential?
- A. CFCs, then HCFCs, then HFCs
- B. HCFCs, then CFCs, then HFCs
- C. HFCs, then HCFCs, then CFCs
- D. CFCs, then HFCs, then HCFCs
Show answer and explanation
Answer: A. CFCs, then HCFCs, then HFCs
CFCs such as R-12 contain the most chlorine and have the highest ozone depletion potential. HCFCs such as R-22 contain hydrogen, which makes them break down sooner in the lower atmosphere, so their potential is lower. HFCs such as R-134a and R-410A contain no chlorine, so they do not deplete ozone, although many of them are strong greenhouse gases.
3. Complete the sentence.
To _____ refrigerant means to reprocess it until it meets the purity specifications EPA sets for refrigerant sold for reuse, which must be confirmed by chemical analysis.
Options for blank 1: recover, recycle, reclaim, recharge
Show answer and explanation
Answer: reclaim
Recover means removing refrigerant from an appliance and storing it in an external container. Recycle means cleaning it, usually by separating oil and filtering, for reuse in equipment of the same owner. Reclaim is the only one that brings refrigerant back to new product specifications, and it is done by an EPA-certified reclaimer, not in the field.
4. You need to pressurize a system to check for leaks. What should you use?
- A. Oxygen from a welding cylinder
- B. Compressed shop air
- C. Dry nitrogen through a pressure regulator and relief valve
- D. Liquid refrigerant charged until the system reaches full pressure
Show answer and explanation
Answer: C. Dry nitrogen through a pressure regulator and relief valve
Dry nitrogen is inert and contains no moisture. Oxygen can react violently with compressor oil and cause an explosion, and shop air brings in moisture and also contains oxygen. A nitrogen cylinder holds far more pressure than a system can take, so the regulator and relief valve are not optional.
5. Which statements about the Clean Air Act venting prohibition are correct?
Select all that apply.
- A. Knowingly venting CFC or HCFC refrigerant during service, repair or disposal is prohibited.
- B. The prohibition also covers HFC substitutes such as R-134a and R-410A.
- C. Venting is allowed when a system holds less than 5 pounds of refrigerant.
- D. Small de minimis releases that happen while you follow proper recovery practices are not a violation.
- E. HFCs may be vented freely because they do not deplete ozone.
Show answer and explanation
Answer: A. Knowingly venting CFC or HCFC refrigerant during service, repair or disposal is prohibited., B. The prohibition also covers HFC substitutes such as R-134a and R-410A., D. Small de minimis releases that happen while you follow proper recovery practices are not a violation.
The prohibition applies at servicing and at disposal, and it extends to substitute refrigerants like HFCs, not only to ozone-depleting ones. What is tolerated is the unavoidable minimal release that happens during good-faith recovery, such as the small amount lost when you disconnect hoses. Charge size does not create an exemption, and small appliances must still be recovered.
6. Why should a refrigerant cylinder never be filled to more than 80 percent of its capacity?
- A. Because EPA charges a fee on cylinders that are full
- B. Because refrigerant cannot be recovered after the cylinder passes 80 percent
- C. Because the scale reading becomes inaccurate above 80 percent
- D. Because liquid expands as it warms, and a cylinder with no vapor space left can rupture
Show answer and explanation
Answer: D. Because liquid expands as it warms, and a cylinder with no vapor space left can rupture
The space above the liquid gives it room to expand. If a full cylinder warms up, for example in a truck on a hot day, the liquid can fill the whole cylinder and hydrostatic pressure rises very fast. That is why recovery cylinders are weighed during filling, or have a float switch, and are never filled past 80 percent.
7. Complete the sentence.
Under Section 608, a small appliance is one that is fully manufactured, charged and hermetically sealed in a factory with _____ or less of refrigerant.
Options for blank 1: 1 pound, 2 pounds, 5 pounds, 10 pounds
Show answer and explanation
Answer: 5 pounds
The definition has two parts: 5 pounds or less, and factory sealed. A household refrigerator, a window air conditioner or a dehumidifier qualifies. A unit that is field-assembled does not, even if its charge is small, and working on small appliances is what Type I certifies you for.
8. You are recovering refrigerant from a small appliance whose compressor does not run, using recovery equipment made after November 15, 1993. What is the minimum requirement?
- A. Recover 100 percent of the charge
- B. Recover 90 percent of the charge
- C. Recover 80 percent of the charge, or evacuate to 4 inches of mercury vacuum
- D. Recover 50 percent of the charge
Show answer and explanation
Answer: C. Recover 80 percent of the charge, or evacuate to 4 inches of mercury vacuum
With equipment made after that date, you must recover 90 percent of the charge when the appliance compressor works and 80 percent when it does not, or pull the appliance down to 4 inches of mercury vacuum in either case. A running compressor helps push refrigerant out, which is why the bar is higher when it works.
9. When you recover from a small appliance with an inoperative compressor, why should you install access valves on both the high side and the low side?
- A. Because refrigerant can stay trapped on one side of the system without a running compressor to move it
- B. Because the law requires two valves on every appliance, whatever its size
- C. Because a single valve would let air into the system
- D. Because the high side valve is needed to add oil during recovery
Show answer and explanation
Answer: A. Because refrigerant can stay trapped on one side of the system without a running compressor to move it
A working compressor moves refrigerant through the system, so one access point can be enough. When it does not run, refrigerant can be held on either side of the metering device, and accessing both sides gets it out faster and more completely. Solderless piercing valves used for this should be removed when the job is done, because they tend to leak over time.
10. Complete the sentence.
System-dependent recovery equipment may not be used on an appliance with a full charge of more than _____ of refrigerant, unless it is a pump-out unit permanently attached to the appliance.
Options for blank 1: 5 pounds, 15 pounds, 50 pounds, 200 pounds
Show answer and explanation
Answer: 15 pounds
System-dependent equipment relies on the appliance's own compressor or pressure to move refrigerant, so it recovers too slowly and too incompletely for larger systems. Above 15 pounds you need self-contained recovery equipment, which has its own compressor and works without help from the appliance.
11. A high-pressure appliance has a full charge of less than 200 pounds. Using recovery equipment made after November 15, 1993, to what level must you evacuate it before opening it?
- A. 0 inches of mercury
- B. 10 inches of mercury vacuum
- C. 15 inches of mercury vacuum
- D. 25 millimeters of mercury absolute
Show answer and explanation
Answer: A. 0 inches of mercury
For high-pressure appliances, EPA's evacuation table sets 0 inches of mercury for a charge under 200 pounds and 10 inches of mercury vacuum for 200 pounds or more, with modern recovery equipment. The 25 millimeters of mercury absolute level belongs to low-pressure appliances. After you reach the level, wait a few minutes and watch the gauges, because a rise in pressure means refrigerant is still in the system.
12. Which of these are signs of a leak in a high-pressure system?
Select all that apply.
- A. Oily residue around a fitting or brazed joint
- B. Head pressure holding steady at its normal reading
- C. Bubbles forming in a soap solution brushed over a joint
- D. An electronic leak detector alarming at one spot
- E. A clean, dry joint with no residue
Show answer and explanation
Answer: A. Oily residue around a fitting or brazed joint, C. Bubbles forming in a soap solution brushed over a joint, D. An electronic leak detector alarming at one spot
Refrigerant carries compressor oil with it, so oil stains at a joint are the classic visual sign of a leak. Soap bubbles and an electronic detector confirm the exact spot. Before you charge or recharge equipment, leak test it, because adding refrigerant to a leaking system only releases more of it.
13. On a large high-pressure system, why do technicians often start by recovering liquid refrigerant?
- A. Because liquid recovery removes moisture from the system
- B. Because liquid moves much more refrigerant in less time than vapor
- C. Because vapor cannot legally be recovered
- D. Because liquid recovery makes evacuation unnecessary
Show answer and explanation
Answer: B. Because liquid moves much more refrigerant in less time than vapor
The same volume of liquid holds far more refrigerant than vapor, so pulling liquid first removes most of the charge quickly. You still have to recover the vapor afterwards and reach the required evacuation level. Shorter hoses, larger diameter hoses and removing valve cores also speed up recovery.
14. When you recharge a low-pressure chiller that has been evacuated to a deep vacuum, why do you add refrigerant vapor before liquid?
- A. Because liquid would contaminate the purge unit
- B. Because vapor is cheaper than liquid
- C. Because the chiller can only be charged through the condenser
- D. Because liquid boiling at very low pressure can freeze the water in the tubes
Show answer and explanation
Answer: D. Because liquid boiling at very low pressure can freeze the water in the tubes
At a deep vacuum, liquid refrigerant flashes and gets very cold, cold enough to freeze the water in the evaporator tubes and split them. Charging vapor first raises the pressure until the refrigerant's saturation temperature is above freezing, and then liquid can follow. Centrifugal chillers are charged through the evaporator charging valve.
15. Which statements about low-pressure chillers are correct?
Select all that apply.
- A. They run at higher pressures than R-410A systems.
- B. Because parts of the system run below atmospheric pressure, leaks let air and moisture in rather than letting refrigerant out.
- C. A purge unit removes air and other noncondensables from the system.
- D. Leak testing should be done by pressurizing the system with oxygen.
- E. During refrigerant evacuation, the water in the tubes should be circulated or drained to prevent freezing.
Show answer and explanation
Answer: B. Because parts of the system run below atmospheric pressure, leaks let air and moisture in rather than letting refrigerant out., C. A purge unit removes air and other noncondensables from the system., E. During refrigerant evacuation, the water in the tubes should be circulated or drained to prevent freezing.
Low-pressure refrigerants such as R-123 boil just above room temperature at atmospheric pressure, so the evaporator of a running chiller sits in a vacuum and a leak pulls air in. That air and moisture raise pressure and cut efficiency, which is what the purge unit is there to remove. Water in the tubes can freeze as pressure drops during evacuation, so keep it moving or drain it.
How the EPA 608 exam works
Section 608 of the Clean Air Act requires anyone who maintains, services, repairs or disposes of equipment that could release refrigerant to be certified. The rule is federal, so the same certification applies in every state. There are four certification types. Type I covers small appliances, meaning units factory sealed with 5 pounds of refrigerant or less, such as household refrigerators and window units. Type II covers high-pressure and very high-pressure equipment, which includes most residential and commercial air conditioning. Type III covers low-pressure equipment, mainly centrifugal chillers. Universal means you passed all three types.
Every test includes a Core section. Under EPA's rule, each test has at least 25 questions from the Core group and at least 25 from each type you are certifying for, so a Universal exam has 100 questions. The passing score set in the rule is 70 percent for the closed-book Type I, Type II, Type III and Universal tests, and 84 percent for a Type I test taken in the mail-in format. Type II and Type III must be taken closed book with a proctor. A Type I mail-in test, or a Core section taken open book, cannot be used toward Universal.
EPA does not run the exam or print the cards itself. You test with an EPA-approved certifying organization, which issues a wallet card within 30 days. The certification does not expire, and you have to keep a copy of your certificate at your place of business. Prices, scheduling and whether you can test online are set by the organization you choose. One thing that often surprises people: car air conditioning is not Section 608. Motor vehicle AC work falls under Section 609, which is a separate certification.
How to use this sampler
The 15 questions follow the order of the exam: six Core questions, then three for Type I, four for Type II and two for Type III. If you are only sitting Core and Type I, take all of them anyway, because the Type II questions on recovery speed and leak signs are useful background for any technician.
Three topics deserve extra attention. The first is the three Rs, recover, recycle and reclaim, which are easy to mix up. The second is the evacuation table, where the required vacuum depends on the appliance type, its charge size and when your recovery equipment was made. The third is safety, especially nitrogen versus oxygen and the 80 percent cylinder fill limit. If you miss one of these here, review the whole topic, not just the single fact.
Some numbers on the exam have changed over the years, including leak repair thresholds, phaseout dates and the maximum penalty, and newer rules under the AIM Act now cover HFC equipment as well. This sampler tests the concepts behind those rules rather than numbers that move. Before your exam, check the current requirements on the EPA Section 608 pages at epa.gov and in the study manual from your certifying organization.
How StudyPDF builds full EPA 608 practice tests from your manual
Fifteen questions can show you which section is shaky. They cannot cover a 100-question Universal exam, and a generic question pool rarely matches the study manual your certifying organization hands you.
StudyPDF works from your material instead. Upload your EPA 608 study manual, your trade school slides or photos of your class notes, press New material, and StudyPDF builds practice exams from those exact pages, sectioned like the real test and graded at the end. Every question is grounded in your material and every explanation cites where the answer comes from.
You do not need a document to start. Name a topic instead, for example Type III recovery or the three Rs, and Bo sets it up with its key concepts so you can build quizzes on it. Your results track which concepts you keep missing, so the next quiz can target them. Starting is free, and the free plan covers about four materials a week.
Written by the StudyPDF team. Last updated 2026-08-19.