EPA 608 Exam Prep

EPA 608 Practice Questions

Every Core question from the EPA 608 Exam Prep app (106) plus 25 sample questions each for Type I, II and III, free, each with the answer and the reasoning behind it. The real exam has 25 questions per section and you need 18 right in each. Want a score? Take the free 10-question test.

Core

The regulations, ozone, the three Rs (recover, recycle, reclaim), safety and shipping. Every technician takes it.

Ozone Depletion

  1. What is the Ozone Depletion Potential (ODP) of HFC refrigerants such as R-134a and R-410A?
  2. Which refrigerant type contains chlorine and has the highest ODP?
  3. Which of the following is an HCFC refrigerant?
  4. What is the Ozone Depletion Potential (ODP) of HFO refrigerants?
  5. What baseline refrigerant is used to establish ODP with a value of 1.0?
  6. What baseline gas is used to establish Global Warming Potential (GWP)?
  7. Where is stratospheric ozone located?
  8. Why is stratospheric ozone vital for life on Earth?
  9. Which element in CFCs and HCFCs is responsible for ozone depletion?
  10. How does chlorine destroy ozone?
  11. What makes HFC refrigerants harmful to the environment?
  12. Which metric compares a gas's global warming impact to carbon dioxide?
  13. Why can CFCs released at ground level damage the ozone layer?
  14. R-410A has a GWP of about 2,088. What does that mean?

Clean Air Act & Montreal Protocol

  1. What is the primary difference between the Montreal Protocol and the Kigali Amendment?
  2. What international agreement first phased out ozone-depleting substances?
  3. What was the primary goal of the original Montreal Protocol?
  4. Which international agreement targets the global phasedown of HFCs?
  5. Since January 1, 2020, how can existing R-22 systems be serviced?
  6. When did U.S. production of CFC refrigerants such as R-12 end?

Section 608 Regulations

  1. Under the AIM Act, EPA regulates HFCs through which three main areas?
  2. Which regulation phases down the production of HFCs in the United States?
  3. Is it legal to vent natural refrigerants like R-290 (propane) or R-744 (CO2)?
  4. What EPA certification is required to purchase HCFC or HFC refrigerants?
  5. When does an EPA Section 608 Technician Certification expire?
  6. How long must records be kept for appliance disposal (5-50 lbs charge)?
  7. What happens if a technician vents an HFC refrigerant like R-410A?
  8. What does the AIM Act authorize the EPA to do regarding HFCs?
  9. Under the AIM Act, what happens to existing HFC systems?
  10. What is the EPA's SNAP program designed to do?
  11. Is it ever legal to intentionally vent an HFC refrigerant like R-134a?
  12. What is an allowable 'de minimis' release of refrigerant?
  13. Are hydrocarbon refrigerants like R-290 exempt from the venting prohibition?
  14. Which refrigerant container may still be sold to a buyer without Section 608 or 609 certification?

Substitute Refrigerants & Oils

  1. Which refrigerant is approved as an exempt substitute for new household fridges?
  2. Which type of oil is most commonly used with HFC refrigerants?
  3. Which oil is primarily used in automotive HFC-134a AC systems?
  4. Which oil was historically the standard for CFC refrigerants?
  5. What does 'hygroscopic' mean regarding refrigeration oils?
  6. Can mineral oil be used to retrofit a CFC system to an HFC refrigerant?
  7. What oil is most commonly used in ternary blends containing HCFCs?

Refrigeration Fundamentals

  1. What characterizes a zeotropic refrigerant blend (400-series)?
  2. Which PT chart value do you use to calculate subcooling for a zeotropic blend?
  3. What happens when a zeotropic blend leaks from a system?
  4. What is the state of refrigerant entering the compressor?
  5. What is the state of refrigerant leaving the condenser?
  6. What component changes a high-pressure liquid to a low-pressure liquid?
  7. What does the 'R' in refrigerant designations (e.g., R-22) stand for?
  8. What type of refrigerant is R-134a?
  9. What type of refrigerant is R-1234yf?
  10. How does a zeotropic blend differ from a pure refrigerant?
  11. What is 'temperature glide' in a zeotropic blend?
  12. What causes fractionation in a zeotropic blend?
  13. What characterizes an azeotropic refrigerant blend (500-series)?
  14. Which of the following is a natural refrigerant?
  15. How is subcooling measured?
  16. What does superheat measure?
  17. When does a PT chart give the actual temperature of a refrigerant from its pressure?
  18. What does refrigerant do inside the evaporator?
  19. Which component raises the pressure and temperature of refrigerant vapor?

Recover, Recycle, Reclaim

  1. According to EPA regulations, what is the strict definition of 'Reclaim' when referring to refrigerants?
  2. What does 'recycle' mean according to EPA guidelines?
  3. What does 'recover' mean according to EPA regulations?
  4. What process requires chemical analysis to verify virgin specifications?
  5. Who may reprocess used refrigerant so it can be sold to a new owner?

Recovery Requirements

  1. What defines 'system-dependent' recovery equipment?
  2. Which rule applies to a technician opening a system with a mixed refrigerant?
  3. What must be done to a recovery cylinder before transferring refrigerant?

Recovery Techniques

  1. How can you safely increase the speed of refrigerant recovery?
  2. Which action speeds up refrigerant recovery from a system?
  3. What should be done to valves to speed up the recovery process?
  4. Which hose setup makes refrigerant recovery faster?

Dehydration & Evacuation

  1. What is the primary purpose of evacuating a refrigeration system?
  2. What chemical is formed when moisture mixes with CFC or HCFC refrigerants?
  3. What tool is required to accurately measure a deep vacuum?
  4. What is the standard target vacuum level for system dehydration?
  5. What happens to the boiling point of water as system pressure drops in a vacuum?
  6. If a micron gauge rises to atmospheric pressure after the pump is off, what does it mean?
  7. If a micron gauge rises and then levels off (e.g., at 2000 microns), what does it mean?

Leak Detection

  1. What gas should be used for safely pressurizing a system to leak test?
  2. Which leak detection method is best for pinpointing an exact leak location?
  3. What is a 'trace gas' used in leak detection?
  4. What is the most effective way to detect a massive system leak quickly?
  5. How does an ultrasonic leak detector find a leak?
  6. When searching for a leak with an electronic detector, how should the probe be moved?

Leak Repair Requirements

  1. Under the AIM Act (2026), what determines HFC repair thresholds?
  2. From January 1, 2026, which HFC appliances fall under EPA's leak repair rules?

Recharging Techniques

  1. How must a zeotropic blend (400-series) be charged into a system?

Safety

  1. Which ASHRAE safety classification applies to mildly flammable refrigerants like R-32 and R-454B that are replacing high-GWP HFCs under the AIM Act?
  2. Under ASHRAE Standard 34, what does an A2L refrigerant classification indicate?
  3. Under ASHRAE Standard 34, what does 'A1' signify?
  4. Under ASHRAE 34, what does the 'B' signify in B2L?
  5. Why must you never pressurize a system with pure oxygen?
  6. Which safety device is installed on all DOT recovery cylinders?
  7. What is the maximum safe fill capacity of a refrigerant recovery cylinder?
  8. Why must you never heat a refrigerant cylinder with an open flame?
  9. What personal protective equipment (PPE) is essential when handling refrigerants?
  10. What physical hazard does liquid refrigerant pose to skin?
  11. What can happen if CFC or HCFC refrigerants are exposed to high heat or open flames?
  12. What happens when refrigerant vapor is inhaled in large quantities?

Shipping

  1. Which agency regulates the specifications of refrigerant shipping cylinders?
  2. When is it legally permissible to use a disposable cylinder for recovery?
  3. How should you safely transport refrigerant cylinders?
  4. What must be done to a disposable cylinder before throwing it away?
  5. What colors are used for approved recovery cylinders?
  6. How often must a reusable DOT recovery cylinder be hydrostatically tested?

Type I sample questions

Small appliances: factory-sealed with 5 lbs of refrigerant or less. These 25 are free here; the app has 100 Type I questions.

  1. What specifically defines a 'small appliance' under EPA Section 608?
  2. What is the maximum refrigerant charge allowed for a Type I small appliance?
  3. When using a self-contained recovery device on a CFC, HCFC, or HFC small appliance with an operating compressor, what percentage of the refrigerant must be recovered?
  4. What is the recovery requirement for a Type I appliance with a non-operating compressor?
  5. Recovery equipment built before November 15, 1993 is used on a small appliance. How much refrigerant must it recover?
  6. Can system-dependent recovery equipment be used on a Type I appliance?
  7. Where is a piercing valve typically installed on a household refrigerator?
  8. Why should a piercing access valve NOT be left permanently on a system?
  9. How many access valves are needed if the compressor operates?
  10. How many access valves are needed if the compressor does NOT operate?
  11. What helps release trapped refrigerant from compressor oil during recovery?
  12. Which refrigerant used in new refrigerators requires ignition-proof equipment?
  13. Under ASHRAE 34, how is Isobutane (R-600a) classified for safety?
  14. What was the primary HFC replacement for R-12 in household refrigerators?
  15. Which oil is most commonly used with HFC-134a in small appliances?
  16. Who is responsible for making sure the refrigerant was removed from a refrigerator before it is scrapped?
  17. How long must a final processor keep the signed statements for disposed small appliances?
  18. Why isn't a ductless mini-split that holds only 3 lbs of refrigerant a small appliance?
  19. What score is needed to pass a mail-in Type I test?
  20. Can a Type I certification earned through a mail-in test count toward Universal certification?
  21. Which certification lets a technician repair a factory-sealed vending machine that holds 1 lb of R-134a?
  22. System-dependent (passive) recovery from a small appliance typically captures the refrigerant in what?
  23. How should a capillary-tube household refrigerator be recharged?
  24. Before recovering refrigerant from a small appliance, where do you first check which refrigerant it holds?
  25. What metering device do most household refrigerators use?

Type II sample questions

High- and very high-pressure appliances: split systems, rooftops, commercial refrigeration. These 25 are free here; the app has 100 Type II questions.

  1. R-22 has a saturation pressure of about 220 psia at 104°F. Which EPA category does an R-22 appliance fall in?
  2. At 104°F, R-134a has a saturation pressure of about 147 psia. Which EPA pressure category is that?
  3. What evacuation level does Table 1 require for a very high-pressure appliance, such as one using R-23?
  4. What evacuation level is required for a Type II appliance with less than 200 lbs of R-22?
  5. What evacuation level is required for a Type II appliance with 200 lbs or more of R-22?
  6. With post-1993 recovery equipment, what level is required before replacing the compressor on a 150-lb R-410A system?
  7. An R-134a system holds 250 lbs. With post-1993 recovery equipment, what level is required?
  8. For a repair that isn't major, what level may a high-pressure appliance be evacuated to instead of the Table 1 vacuum?
  9. Under the updated AIM Act regulations (effective Jan 1, 2026), what is the new threshold for mandatory leak monitoring and repair on comfort cooling appliances containing HFCs?
  10. Under the AIM Act (2026), what is the leak repair threshold for commercial HFC systems with 50+ lbs?
  11. What is the leak repair threshold for an Industrial Process Refrigeration (IPR) system with 50+ lbs?
  12. What is the leak repair threshold for Comfort Cooling appliances containing 50 or more pounds?
  13. How long do you have to repair a 50+ lb commercial system if the leak rate exceeds the threshold?
  14. To speed up recovery on a Type II system, how should refrigerant be removed first?
  15. How can a technician legally and safely speed up the refrigerant recovery process?
  16. Where should you recover refrigerant from if the system has a receiver?
  17. Why must you never pressurize a refrigeration system with oxygen or compressed air?
  18. What gas is strictly used with a trace amount of refrigerant to leak test a system?
  19. What is the approved method to pinpoint a refrigerant leak after an electronic detector finds the general area?
  20. Where is a leak most likely to occur in a belt-driven open compressor?
  21. Can you pipe two pressure relief valves in series?
  22. What prevents refrigerant from migrating to the compressor oil during the off-cycle?
  23. Why must you never start a hermetic compressor while it is in a deep vacuum?
  24. What service pressure rating must a recovery cylinder have to hold R-410A?
  25. Recovering R-454B, an A2L refrigerant, requires what kind of recovery machine?

Type III sample questions

Low-pressure appliances: centrifugal chillers running under a vacuum. These 25 are free here; the app has 100 Type III questions.

  1. Under EPA's definition, a low-pressure appliance uses a refrigerant with what saturation pressure at 104°F?
  2. Which of the following is considered a low-pressure refrigerant?
  3. Which certification covers servicing a centrifugal chiller charged with R-1233zd(E)?
  4. At what pressure does the rupture disc on a low-pressure centrifugal chiller typically burst?
  5. Where is the rupture disc typically located on a low-pressure chiller?
  6. How is the rupture disc piped to safely vent refrigerant?
  7. What is the maximum safe test pressure for a low-pressure centrifugal chiller?
  8. What is the recommended method to leak-test a low-pressure chiller without exceeding rupture disc limits?
  9. What is the primary purpose of a purge unit on a low-pressure centrifugal chiller system?
  10. Where does the purge unit take its suction from?
  11. What does frequent operation of the purge unit indicate?
  12. What indicates a tube leak in a low-pressure centrifugal chiller?
  13. How do you find a leak in the water tubes of a low-pressure chiller?
  14. Why must evaporator and condenser water pumps run when recovering refrigerant from a low-pressure chiller?
  15. What is the most efficient way to begin recovering refrigerant from a low-pressure chiller?
  16. What must be done after recovering the liquid from a low-pressure chiller?
  17. How should compressor oil be prepared before removal from a low-pressure chiller?
  18. What is the standard evacuation level for a low-pressure appliance?
  19. The Type III evacuation level of 25 mm Hg absolute equals about how many microns?
  20. Why is a low-pressure chiller introduced with refrigerant vapor before liquid refrigerant during the charging process?
  21. Before charging liquid into a chiller, what must the system pressure be?
  22. Why must low-pressure chillers be designed to be completely airtight?
  23. R-123 is rated B1 under ASHRAE 34. What does that mean?
  24. Which HCFO refrigerant is replacing R-123 in new low-pressure chillers?
  25. A chiller with a 1,000-lb full charge needs 50 lbs added, 73 days after the last addition. What is its annualized leak rate?

Practice questions written for study and checked against 40 CFR Part 82, Subpart F. They are not the official EPA exam questions, and this site is not affiliated with the U.S. EPA.