EPA 608 Type II mock exam
Core plus Type II, 50 questions: the test you take for Type II certification.
Before you start
- 50 questions: 25 Core and 25 Type 2.
- Each section is scored on its own. On the real exam you need 70% in a section to pass it, and the results page shows your score against that mark.
- None of these questions appear on the practice pages, so this is a fair check of what you know.
- One question per page, with the answer and explanation shown as you go. No timer and no sign-up; your answers are saved in this browser so you can stop and come back.
What this test covers
- Core: Ozone depletion, the Clean Air Act, Section 608 rules, the three Rs, recovery basics, safety and shipping. Every 608 test includes 25 Core questions. Practice Core questions.
- Type II: Medium-, high- and very high-pressure appliances such as residential split systems, rooftop units and supermarket refrigeration. Practice Type 2 questions.
Answer key: every answer, explained
Take the test first: the answers are here for checking afterwards. Each one says why it is right, why each other choice is wrong, and which rule it comes from.
Core
1. An older centrifugal chiller is charged with R-11. What type of refrigerant is R-11?
- HFC
- HCFC
- HFO
- CFCCorrect answer
Why “CFC” is correct
R-11 is a chlorofluorocarbon, and it is the reference refrigerant for ozone depletion potential with an ODP of 1.0. Its replacement in many chillers, R-123, is an HCFC.
Source: EPA: Test Topics
Why the other answers are wrong
- HFC — HFCs contain no chlorine; R-11 does.
- HCFC — R-123, not R-11, is the HCFC used in many newer low-pressure chillers.
- HFO — HFOs are recent low-GWP refrigerants, not R-11.
2. R-123 replaced R-11 in many low-pressure chillers. How is R-123 classified?
- HCFCCorrect answer
- CFC
- HFC
- Hydrocarbon
Why “HCFC” is correct
R-123 is a hydrochlorofluorocarbon. It contains chlorine and so still depletes ozone, but far less than the CFC R-11 it replaced. Like other HCFCs, it is being phased out.
Source: EPA: Test Topics
Why the other answers are wrong
- CFC — R-11 is the CFC; R-123 contains hydrogen as well.
- HFC — R-123 contains chlorine, so it is not an HFC.
- Hydrocarbon — R-123 contains chlorine and fluorine, so it is not a hydrocarbon.
3. What range of ozone depletion potential do HCFC refrigerants fall in, compared with CFC-11 at 1.0?
- About 0.01 to 0.1Correct answer
- About 0.6 to 1.0
- About 1.0 to 10
- Exactly zero
Why “About 0.01 to 0.1” is correct
HCFCs have ODPs of roughly 0.01 to 0.1. They still contain chlorine, but much of each molecule breaks down in the lower atmosphere before it reaches the stratosphere. The highest-ODP HCFCs were phased out first.
Source: EPA: Test Topics
Why the other answers are wrong
- About 0.6 to 1.0 — 0.6 to 1.0 is the range of the common CFCs.
- About 1.0 to 10 — ODPs up to 10 belong to the halons, not HCFCs.
- Exactly zero — An ODP of zero belongs to HFCs, which contain no chlorine.
4. Which part of the Clean Air Act directs EPA to protect the stratospheric ozone layer, including rules on recycling refrigerants?
- Title I
- Title IV
- Title VICorrect answer
- Title IX
Why “Title VI” is correct
Title VI of the Clean Air Act, added in the 1990 amendments, directs EPA to protect stratospheric ozone. It covers production of ozone-depleting substances, the recycling and handling of refrigerants, and the evaluation of substitutes. Section 608 is part of Title VI.
Source: EPA: Test Topics
Why the other answers are wrong
- Title I — Title I deals with ground-level air quality standards.
- Title IV — Title IV deals with acid rain.
- Title IX — There is no Title IX ozone program in the Clean Air Act.
5. A building owner who is not a technician opens a valve and releases R-410A from his own rooftop unit. Does the venting prohibition apply to him?
- No, it applies only to certified technicians
- Yes, it applies to anyone servicing or disposing of oneCorrect answer
- No, owners may do what they want with their own equipment
- Yes, but only if the unit holds more than 50 pounds
Why “Yes, it applies to anyone servicing or disposing of one” is correct
40 CFR 82.154(a)(1) says no person maintaining, servicing, repairing or disposing of an appliance may knowingly vent refrigerant. "Person" includes individuals and companies, so the rule applies to owners as well as technicians.
Source: 40 CFR 82.154(a)(1); 40 CFR 82.152
Why the other answers are wrong
- No, it applies only to certified technicians — The prohibition covers every person, not just certified technicians.
- No, owners may do what they want with their own equipment — Owning the equipment does not give permission to vent.
- Yes, but only if the unit holds more than 50 pounds — The venting prohibition has no charge-size threshold.
6. Under 40 CFR 82.152, which of these is not considered "opening an appliance"?
- Removing a compressor for replacement
- Connecting hoses and gauges to measure pressureCorrect answer
- Cutting a refrigerant line to replace a drier
- Unbrazing a condenser coil
Why “Connecting hoses and gauges to measure pressure” is correct
The definition of opening an appliance covers service that would release refrigerant to the atmosphere. Connecting and disconnecting hoses and gauges to measure pressures, add refrigerant or recover refrigerant is specifically not "opening," though it still requires certification.
Source: 40 CFR 82.152
Why the other answers are wrong
- Removing a compressor for replacement — Removing a compressor exposes the refrigerant circuit and is opening the appliance.
- Cutting a refrigerant line to replace a drier — Cutting a line opens the refrigerant circuit.
- Unbrazing a condenser coil — Unbrazing a coil opens the refrigerant circuit.
7. Under 40 CFR 82.154(e), a new small appliance sold in the U.S. must come with what feature to make recovery possible?
- A pressure relief valve
- A sight glass
- A permanently attached recovery unit
- A process stubCorrect answer
Why “A process stub” is correct
New small appliances must have a process stub, a length of tubing that gives access to the refrigerant and can be resealed. Larger appliances must have a servicing aperture. Both make recovery at service and disposal possible.
Source: 40 CFR 82.154(e); 40 CFR 82.152
Why the other answers are wrong
- A pressure relief valve — Relief valves protect against overpressure but are not the required access point.
- A sight glass — A sight glass shows liquid flow and is not required for recovery.
- A permanently attached recovery unit — Permanently attached recovery units are not required.
8. A refrigerant wholesaler sells R-454B to a contractor. Which records must the wholesaler keep, and for how long?
- The address of the appliance being serviced, for five years
- The technician's test score, for one year
- Invoices with buyer, date and quantity, for three yearsCorrect answer
- No records, because R-454B is a substitute
Why “Invoices with buyer, date and quantity, for three years” is correct
Under 40 CFR 82.154(c)(3), sellers of class I, class II and non-exempt substitute refrigerants must keep invoices showing the purchaser's name, the date of sale and the quantity sold, plus any proof of a certified employee, for three years.
Source: 40 CFR 82.154(c)(3)
Why the other answers are wrong
- The address of the appliance being serviced, for five years — The wholesaler does not have to record where the refrigerant will be used.
- The technician's test score, for one year — Test scores are kept by certifying programs, not wholesalers.
- No records, because R-454B is a substitute — Non-exempt substitutes have been covered by the sales restriction since January 1, 2018.
9. After taking the Section 608 test, how soon must the certifying program send the results?
- Within 7 days
- Within 30 daysCorrect answer
- Within 90 days
- Within one year
Why “Within 30 days” is correct
Appendix D requires certifying programs to give applicants their results no later than 30 days from the test date and to issue the wallet card within 30 days. For mail-in Type I tests the 30 days run from when the program receives the completed test.
Source: 40 CFR Part 82, Subpart F, Appendix D; EPA: Section 608 Q&A
Why the other answers are wrong
- Within 7 days — Seven days is not the deadline in the rule.
- Within 90 days — Ninety days is longer than the rule allows.
- Within one year — One year is far longer than the 30-day deadline.
10. A technician wants to service small appliances, high-pressure systems and low-pressure chillers. Which certification covers all of them?
- Type II
- Type III
- UniversalCorrect answer
- Core only
Why “Universal” is correct
Universal certification covers everything that Types I, II and III cover. It requires passing Core and all three type sections under closed-book, proctored conditions, either in one sitting or by combining separate passing scores.
Source: 40 CFR 82.161(a)(1); 40 CFR Part 82, Subpart F, Appendix D
Why the other answers are wrong
- Type II — Type II does not cover small appliances or low-pressure chillers.
- Type III — Type III covers only low-pressure appliances.
- Core only — Core alone does not certify a technician for any equipment.
11. A technician plans to convert an R-22 system to a substitute refrigerant. What must be done with the R-22 first?
- Recover it with certified recovery equipmentCorrect answer
- Vent it, since R-22 is being phased out
- Leave it in and add the substitute on top
- Mix it with the substitute in a cylinder
Why “Recover it with certified recovery equipment” is correct
The existing charge must be recovered before the system is opened for a retrofit. The new refrigerant's lubricant and component requirements are then followed, because a retrofit is not a simple drop-in.
Source: 40 CFR 82.154(a); 40 CFR 82.152
Why the other answers are wrong
- Vent it, since R-22 is being phased out — Venting R-22 is a violation, phaseout or not.
- Leave it in and add the substitute on top — Adding a substitute on top creates a mixture of unknown composition.
- Mix it with the substitute in a cylinder — Mixing refrigerants makes them hard or impossible to reclaim.
12. Which lubricant was traditionally used in R-12 CFC refrigeration systems?
- Silicone oil
- Polyolester oil
- Polyalkylene glycol oil
- Mineral oilCorrect answer
Why “Mineral oil” is correct
CFC systems such as those using R-12 traditionally used mineral oil. Many substitute refrigerants, including HFCs, do not mix with mineral oil, which is why retrofits often require an oil change.
Source: EPA: Test Topics
Why the other answers are wrong
- Silicone oil — Silicone oil is not used as a refrigeration compressor lubricant.
- Polyolester oil — Polyolester oil is the usual partner for HFCs such as R-134a.
- Polyalkylene glycol oil — PAG oil is used mainly in automotive R-134a systems.
13. In a running system, what is in the liquid line between the condenser and the metering device?
- High-pressure liquidCorrect answer
- Low-pressure vapor
- High-pressure vapor
- Low-pressure liquid and vapor
Why “High-pressure liquid” is correct
After the condenser removes heat, the refrigerant is a high-pressure liquid, usually slightly subcooled. It flows through the liquid line to the metering device, where its pressure drops.
Source: EPA: Test Topics
Why the other answers are wrong
- Low-pressure vapor — Low-pressure vapor is in the suction line.
- High-pressure vapor — High-pressure vapor is in the discharge line before the condenser.
- Low-pressure liquid and vapor — A low-pressure mix is found after the metering device, in the evaporator.
14. When a single-component refrigerant is boiling in the evaporator at a steady pressure, what happens to its temperature?
- It rises steadily as it boils
- It stays about the same while liquid remainsCorrect answer
- It falls steadily as it boils
- It swings up and down with each compressor stroke
Why “It stays about the same while liquid remains” is correct
While a pure refrigerant changes from liquid to vapor at a fixed pressure, it stays at its saturation temperature; the heat it absorbs goes into boiling, not into raising temperature. Only after all liquid has boiled does the vapor begin to warm (superheat).
Source: EPA: Test Topics
Why the other answers are wrong
- It rises steadily as it boils — Temperature rises only after all the liquid has boiled off.
- It falls steadily as it boils — At constant pressure the boiling temperature does not fall.
- It swings up and down with each compressor stroke — Saturation temperature follows pressure, not compressor strokes.
15. Why do technicians use low-loss fittings on their hoses?
- To filter moisture out of the refrigerant as it flows
- To make hoses connect faster
- To cut refrigerant loss when hoses are disconnectedCorrect answer
- To raise the pressure rating of the hose
Why “To cut refrigerant loss when hoses are disconnected” is correct
40 CFR 82.152 defines a low-loss fitting as one that closes automatically or manually when disconnected, minimizing refrigerant released from hoses, appliances and recovery machines. It keeps the trapped hose charge from escaping.
Source: 40 CFR 82.152
Why the other answers are wrong
- To filter moisture out of the refrigerant as it flows — Fittings do not filter moisture; filter-driers do.
- To make hoses connect faster — Speed of connection is not the purpose.
- To raise the pressure rating of the hose — The fitting does not change the hose pressure rating.
16. A compressor burnout has left the R-22 in a system acidic and dirty. What must the technician do with it?
- Vent it, since it cannot be reused
- Mix it with clean R-22 to dilute it
- Leave it in the system
- Recover it into a recovery cylinderCorrect answer
Why “Recover it into a recovery cylinder” is correct
Recovery means removing refrigerant in any condition and storing it in an external container. Contaminated refrigerant must still be recovered; it can then be recycled for the same owner, sent for reclamation, or destroyed.
Source: 40 CFR 82.152; 40 CFR 82.154(a)
Why the other answers are wrong
- Vent it, since it cannot be reused — Contamination is not a reason to vent.
- Mix it with clean R-22 to dilute it — Diluting with clean refrigerant spreads the contamination.
- Leave it in the system — The system cannot be opened for repair with the refrigerant left in it.
17. In a recycling machine, what do the replaceable core filter-driers reduce?
- The amount of refrigerant in the cylinder
- Chlorine content of the refrigerant
- The refrigerant's ozone depletion potential
- Moisture, acidity and particlesCorrect answer
Why “Moisture, acidity and particles” is correct
40 CFR 82.152 notes that recycled refrigerant is generally cleaned by oil separation and passes through devices such as replaceable core filter-driers, which reduce moisture, acidity and particulate matter.
Source: 40 CFR 82.152
Why the other answers are wrong
- The amount of refrigerant in the cylinder — Filter-driers clean refrigerant; they are not meant to reduce the amount.
- Chlorine content of the refrigerant — Chlorine is part of the refrigerant molecule and is not filtered out.
- The refrigerant's ozone depletion potential — ODP is a property of the chemical and does not change.
18. Why should a new recovery cylinder be evacuated before its first use?
- To check that the cylinder is the correct color and type
- To remove air that would mix with the refrigerantCorrect answer
- To pre-cool the cylinder walls
- To meet the 80 percent fill limit
Why “To remove air that would mix with the refrigerant” is correct
A cylinder full of air would add non-condensables to the recovered refrigerant and raise cylinder pressure. Evacuating it first leaves a clean, empty container.
Source: EPA: Test Topics
Why the other answers are wrong
- To check that the cylinder is the correct color and type — Evacuation has nothing to do with cylinder color.
- To pre-cool the cylinder walls — Pulling a vacuum does not meaningfully cool the cylinder.
- To meet the 80 percent fill limit — The fill limit is met by weighing, not by evacuation.
19. Before recovering from an unfamiliar system, why should the technician confirm which refrigerant it holds?
- To pick the right cylinder and avoid mixingCorrect answer
- To decide whether the refrigerant may be vented
- To set the thermostat correctly
- To find the date the system was made
Why “To pick the right cylinder and avoid mixing” is correct
Each refrigerant should go into its own cylinder, so knowing the refrigerant first keeps it from being mixed with another. Check the nameplate and the system pressures before connecting.
Source: EPA: Test Topics
Why the other answers are wrong
- To decide whether the refrigerant may be vented — Non-exempt refrigerants may never be vented.
- To set the thermostat correctly — The thermostat setting has nothing to do with recovery.
- To find the date the system was made — The manufacture date is on the nameplate, but that is not the reason for identifying the refrigerant.
20. After evacuation the vacuum pump is valved off. The micron reading rises, then levels off and holds. What does this most likely mean?
- The vacuum is deep enough to charge
- The system has a large leak to the atmosphere
- Moisture is still boiling off inside the systemCorrect answer
- The micron gauge has failed
Why “Moisture is still boiling off inside the system” is correct
A reading that rises and then levels off usually means moisture or refrigerant is still turning to vapor inside a tight system. A reading that keeps rising without leveling off suggests a leak. More evacuation is needed before charging.
Source: EPA: Test Topics
Why the other answers are wrong
- The vacuum is deep enough to charge — A significant rise shows the system is not yet dry.
- The system has a large leak to the atmosphere — A leak to the atmosphere keeps the reading rising instead of leveling off.
- The micron gauge has failed — A gauge that responds this way is working.
21. Why must a refrigerant cylinder never be heated with a torch?
- The pressure can rise rapidly and rupture the cylinderCorrect answer
- The flame will turn the refrigerant into oxygen
- It voids the cylinder's color code
- It makes the refrigerant flammable
Why “The pressure can rise rapidly and rupture the cylinder” is correct
Heating a cylinder with an open flame can raise its pressure and weaken the metal, causing a rupture or explosion. Open flames can also break refrigerant down into toxic products.
Source: EPA: Test Topics
Why the other answers are wrong
- The flame will turn the refrigerant into oxygen — Heat does not turn refrigerant into oxygen.
- It voids the cylinder's color code — The danger is rupture, not the color code.
- It makes the refrigerant flammable — Heating does not make a nonflammable refrigerant flammable; the hazard is pressure.
22. How can a technician make sure a recovery cylinder stays under the 80 percent fill limit?
- Stop as soon as the recovery machine sounds strained
- Watch the cylinder pressure gauge
- Feel the side of the cylinder for cold spots
- Weigh it and compare with its allowed fill weightCorrect answer
Why “Weigh it and compare with its allowed fill weight” is correct
Pressure in a cylinder depends on temperature, not on how full it is, so a gauge cannot show the fill level. Weighing the cylinder, or using a float switch on cylinders that have one, shows how much liquid is inside.
Source: EPA: Test Topics
Why the other answers are wrong
- Stop as soon as the recovery machine sounds strained — Machine sound does not measure fill level.
- Watch the cylinder pressure gauge — Cylinder pressure follows temperature, not the amount of liquid.
- Feel the side of the cylinder for cold spots — Cold spots are an unreliable guess at the liquid level.
23. A technician will pressure-test a system with nitrogen. What limit should the test pressure respect?
- The full pressure available from the nitrogen cylinder
- The rated test pressure for that systemCorrect answer
- Whatever pressure the relief valve allows
- At least twice the system's normal operating pressure
Why “The rated test pressure for that system” is correct
The test pressure must not exceed what the system and its components are built for, as shown on the nameplate or in the manufacturer's instructions. A regulator sets that pressure, and a relief valve protects against regulator failure.
Source: EPA: Test Topics
Why the other answers are wrong
- The full pressure available from the nitrogen cylinder — Full cylinder pressure can be thousands of psig and would burst the system.
- Whatever pressure the relief valve allows — The relief valve is a backup, not the target pressure.
- At least twice the system's normal operating pressure — Doubling operating pressure can exceed the system rating.
24. A refrigerant leak has made the air in a small mechanical room stuffy and you feel dizzy. What should you do first?
- Light a torch to burn off the refrigerant
- Keep working quickly to finish the repair
- Leave the area and ventilate itCorrect answer
- Lie down on the floor until it passes
Why “Leave the area and ventilate it” is correct
Dizziness is a warning of oxygen deprivation or refrigerant overexposure. Get to fresh air, ventilate the space, and return only when it is safe or with proper breathing equipment.
Source: EPA: Test Topics
Why the other answers are wrong
- Light a torch to burn off the refrigerant — An open flame can break refrigerant down into toxic gases.
- Keep working quickly to finish the repair — Staying in the space can lead to unconsciousness or heart effects.
- Lie down on the floor until it passes — Refrigerant vapor collects low, so lying on the floor is the worst place to be.
25. What does the DOT classification tag on a refrigerant cylinder tell carriers and handlers?
- The technician who filled the cylinder
- The date the refrigerant was made
- The hazard class of the contentsCorrect answer
- The price per pound
Why “The hazard class of the contents” is correct
The Department of Transportation classification tag shows the hazard class of the cylinder's contents, such as nonflammable gas, so carriers handle it correctly. It goes alongside a label identifying the refrigerant itself.
Source: EPA: Test Topics
Why the other answers are wrong
- The technician who filled the cylinder — The tag does not identify who filled the cylinder.
- The date the refrigerant was made — Manufacture date is not what the DOT tag shows.
- The price per pound — Pricing is not part of hazard labeling.
Type II
26. A 150-pound R-22 comfort-cooling chiller exceeded its 10 percent trigger rate and was repaired. How often must it be given leak inspections afterward?
- Every three months for four quarters
- Once a month for a year
- Once a year until it stays under the rate for a yearCorrect answer
- No further inspections once the repair has passed its tests
Why “Once a year until it stays under the rate for a year” is correct
Comfort cooling appliances that exceed the trigger rate get a leak inspection once per calendar year until the owner shows, through leak rate calculations, that the appliance has not exceeded the rate for one year. Quarterly inspections apply only to commercial and industrial process systems of 500 pounds or more.
Source: 40 CFR 82.157(g)(1)
Why the other answers are wrong
- Every three months for four quarters — Quarterly inspections are for commercial and industrial process refrigeration of 500 pounds or more.
- Once a month for a year — No monthly schedule appears in the rule.
- No further inspections once the repair has passed its tests — Inspections continue until the appliance stays under the rate for a year.
27. A technician has two recovery machines, one built in 1991 and one built in 2020, for a 350-pound R-134a chiller that needs a new evaporator. Which statement is correct?
- Both machines must reach 15 inches of Hg vacuum
- The older machine must reach 4 inches; the newer one must reach 15 inchesCorrect answer
- The older machine must reach 10 inches; the newer one must reach 15 inches
- Both machines must reach 0 inches of Hg vacuum
Why “The older machine must reach 4 inches; the newer one must reach 15 inches” is correct
R-134a is medium-pressure, and this chiller holds 200 pounds or more. Table 1 sets 4 inches of Hg vacuum for equipment made before November 15, 1993 and 15 inches for equipment made on or after that date.
Source: 40 CFR 82.156(a), Table 1; 40 CFR 82.152
Why the other answers are wrong
- Both machines must reach 15 inches of Hg vacuum — The older-equipment column for this row is 4 inches, not 15.
- The older machine must reach 10 inches; the newer one must reach 15 inches — 10 inches is the newer-equipment level for medium-pressure appliances under 200 pounds.
- Both machines must reach 0 inches of Hg vacuum — 0 inches is the level for very high-pressure and small high-pressure appliances.
28. Under 40 CFR 82.152, an appliance charged with R-407C is classified as:
- low-pressure
- medium-pressure
- very high-pressure
- high-pressureCorrect answer
Why “high-pressure” is correct
R-407C is one of EPA's listed examples of a high-pressure refrigerant, with a saturation pressure between 170 and 355 psia at 104 °F. R-22, R-407A, R-410A and R-502 are the others listed.
Source: 40 CFR 82.152
Why the other answers are wrong
- low-pressure — Low-pressure refrigerants include R-11 and R-123.
- medium-pressure — Medium-pressure refrigerants include R-134a and R-12.
- very high-pressure — Very high-pressure refrigerants include R-23 and R-508B.
29. A 200-pound R-22 commercial refrigeration system received 30 pounds of refrigerant over the previous 365 days. Using the rolling average method, what is its leak rate, and must it be repaired under Part 82?
- 15 percent; no repair is required at the 20 percent rateCorrect answer
- 30 percent; repair is required
- 15 percent; repair is required because it exceeds the 10 percent rate
- 6.7 percent; no repair is required
Why “15 percent; no repair is required at the 20 percent rate” is correct
The rolling average method divides the pounds added over the past 365 days by the full charge: 30 / 200 = 0.15, or 15 percent. Commercial refrigeration has a 20 percent trigger rate, so this appliance is under it.
Source: 40 CFR 82.152; 40 CFR 82.157(c)
Why the other answers are wrong
- 30 percent; repair is required — 30 is the pounds added, not the percentage of the charge.
- 15 percent; repair is required because it exceeds the 10 percent rate — The 10 percent rate is for comfort cooling, not commercial refrigeration.
- 6.7 percent; no repair is required — This divides the charge by the pounds added the wrong way round.
30. Recovery from a 120-pound R-22 system on a hot roof is going slowly. Which pair of actions would both speed it up?
- Heat the recovery cylinder and cool the appliance
- Lower the machine speed and close the liquid valve
- Use longer hoses and recover vapor first
- Chill the recovery cylinder and warm the applianceCorrect answer
Why “Chill the recovery cylinder and warm the appliance” is correct
Chilling the recovery vessel lowers its pressure, and heating the appliance raises the pressure of the refrigerant being removed. Both widen the pressure difference that moves refrigerant into the cylinder.
Source: EPA: Test Topics
Why the other answers are wrong
- Heat the recovery cylinder and cool the appliance — This does the opposite of each helpful step and narrows the pressure difference.
- Lower the machine speed and close the liquid valve — Closing off the liquid and slowing the machine both slow recovery.
- Use longer hoses and recover vapor first — Longer hoses restrict flow, and vapor-first is slower than liquid-first.
31. Where should a relief valve be placed when pressurizing an R-410A system with nitrogen for a leak test?
- Downstream of the nitrogen regulatorCorrect answer
- On the recovery cylinder
- Inside the compressor
- No relief valve is needed with a regulator
Why “Downstream of the nitrogen regulator” is correct
A relief valve in the line after the regulator protects the system if the regulator fails or is set too high. It vents nitrogen before the system reaches a dangerous pressure.
Source: EPA: Test Topics
Why the other answers are wrong
- On the recovery cylinder — The recovery cylinder is not part of the nitrogen test setup.
- Inside the compressor — A relief valve cannot be fitted inside the compressor for testing.
- No relief valve is needed with a regulator — Regulators can fail, so a relief valve is still good practice.
32. An R-407A appliance with a 260-pound charge is being dismantled for scrap. Using recovery equipment made in 2017, what evacuation level is required?
- 0 inches of Hg vacuum
- 4 inches of Hg vacuum
- 10 inches of Hg vacuumCorrect answer
- 15 inches of Hg vacuum
Why “10 inches of Hg vacuum” is correct
Recycling an appliance for scrap is disposal, which requires the Table 1 levels. R-407A is high-pressure, and a high-pressure appliance of 200 pounds or more needs 10 inches of Hg vacuum with equipment made on or after November 15, 1993.
Source: 40 CFR 82.156(a), Table 1; 40 CFR 82.152
Why the other answers are wrong
- 0 inches of Hg vacuum — 0 inches applies to high-pressure appliances under 200 pounds.
- 4 inches of Hg vacuum — 4 inches is for the same row with pre-1993 equipment.
- 15 inches of Hg vacuum — 15 inches is for medium-pressure appliances of 200 pounds or more.
33. On an R-22 system, the evaporator saturation temperature is 40 °F and the suction line at the evaporator outlet measures 70 °F. What is the superheat, and what might it suggest?
- 30 °F; possibly low charge from a leakCorrect answer
- 30 °F; this points to an overcharged system
- 110 °F; a failed compressor
- 40 °F; a normal reading
Why “30 °F; possibly low charge from a leak” is correct
Superheat is the suction line temperature minus the saturation temperature: 70 - 40 = 30 °F. Superheat that high is well above normal for most systems, and excessive superheat is one of the signs EPA lists for a leak, because an undercharged evaporator runs out of liquid early.
Source: EPA: Test Topics
Why the other answers are wrong
- 30 °F; this points to an overcharged system — An overcharge tends to lower superheat, not raise it.
- 110 °F; a failed compressor — This adds the temperatures instead of subtracting them.
- 40 °F; a normal reading — 40 °F is the saturation temperature, not the superheat.
34. The owner of a leaking 300-pound R-22 commercial system will retire it and install a new system that uses a refrigerant exempt under 40 CFR 82.154(a). How long is automatically allowed to retire the old appliance?
- 12 months
- 18 monthsCorrect answer
- 24 months
- 30 months
Why “18 months” is correct
Owners of any appliance type are automatically allowed 18 months to retire an appliance if the replacement uses a substitute refrigerant exempted under 82.154(a), such as certain natural refrigerants. Otherwise the plan schedule is one year.
Source: 40 CFR 82.157(i)(1)
Why the other answers are wrong
- 12 months — 12 months is the normal schedule without the exempt-substitute extension.
- 24 months — 24 months is not a period named in this rule.
- 30 months — 30 months is not a period named in this rule.
35. A refrigerant has a saturation pressure of 400 psia at 104 °F. How is an appliance using it classified?
- Medium-pressure
- High-pressure
- Very high-pressureCorrect answer
- Low-pressure
Why “Very high-pressure” is correct
Very high-pressure appliances use a refrigerant with a saturation pressure above 355 psia at 104 °F, or a critical temperature below 104 °F. 400 psia is above the high-pressure ceiling of 355 psia.
Source: 40 CFR 82.152
Why the other answers are wrong
- Medium-pressure — Medium-pressure tops out at 170 psia.
- High-pressure — High-pressure tops out at 355 psia.
- Low-pressure — Low-pressure is below 45 psia.
36. A technician recovered refrigerant from a 30-pound R-22 rooftop unit before it was scrapped. What records must the technician keep, and for how long?
- None, because the unit holds less than 50 pounds
- Company, location, date and refrigerant type, for three yearsCorrect answer
- A leak rate calculation, for one year
- A copy of the owner's retirement plan for the unit, for five years
Why “Company, location, date and refrigerant type, for three years” is correct
Since 2018, technicians who evacuate appliances with more than 5 and less than 50 pounds for disposal must keep records for three years. They include the company name, appliance location, date of recovery and type of refrigerant, plus monthly totals and transfers for reclamation or destruction.
Source: 40 CFR 82.156(a)(3)
Why the other answers are wrong
- None, because the unit holds less than 50 pounds — The 50-pound threshold is for leak repair; disposal records cover appliances over 5 and under 50 pounds.
- A leak rate calculation, for one year — No leak rate calculation is required at disposal, and the period is three years.
- A copy of the owner's retirement plan for the unit, for five years — Retirement plans belong to the leak repair rules, not disposal records.
37. A walk-in freezer at a restaurant holds 20 pounds of R-404A, an HFC. Under the 40 CFR Part 84 rule in effect from January 1, 2026, what trigger leak rate applies?
- 10 percent
- 30 percent
- 20 percentCorrect answer
- None; it is below 50 pounds
Why “20 percent” is correct
Part 84 leak repair covers appliances with 15 pounds or more of an HFC with a global warming potential above 53, such as R-404A. Restaurant refrigeration is commercial refrigeration under 40 CFR 84.102, which has a 20 percent trigger rate.
Source: 40 CFR 84.106(a); 40 CFR 84.106(c); 40 CFR 84.102
Why the other answers are wrong
- 10 percent — 10 percent is the comfort cooling rate.
- 30 percent — 30 percent is the industrial process refrigeration rate.
- None; it is below 50 pounds — The 50-pound threshold is for Part 82; Part 84 starts at 15 pounds.
38. Why should compressed shop air not be used to pressurize an R-22 system for a leak test?
- It is lighter than nitrogen
- It is exempt from the venting rules
- It cannot be regulated
- It carries oxygen and moisture into the systemCorrect answer
Why “It carries oxygen and moisture into the system” is correct
Air contains oxygen, which can form a combustible mix with compressor oil under pressure, and it carries moisture into the system. Dry nitrogen avoids both problems.
Source: EPA: Test Topics
Why the other answers are wrong
- It is lighter than nitrogen — Weight is not the reason air is unsuitable.
- It is exempt from the venting rules — Venting rules are not why air is avoided.
- It cannot be regulated — Air pressure can be regulated; the gas itself is the problem.
39. A technician pulls a 200-pound R-22 system down to 10 inches of Hg vacuum, closes the valves, and five minutes later the gauge reads 2 psig. What does this mean?
- The gauge needs recalibrating
- Air has leaked into the system through the hose connections
- Refrigerant is still in the liquid or the oilCorrect answer
- The system is ready to open
Why “Refrigerant is still in the liquid or the oil” is correct
A pressure rise after recovery stops shows refrigerant is still boiling off, from leftover liquid or from the oil. The technician must resume recovery until the required level holds.
Source: EPA: Test Topics; 40 CFR 82.156(a)
Why the other answers are wrong
- The gauge needs recalibrating — A rise like this is the expected sign of remaining refrigerant, not a gauge fault.
- Air has leaked into the system through the hose connections — Air leaking in is not the usual reason for a quick climb above 0 psig.
- The system is ready to open — The required level is no longer met, so the system cannot be opened.
40. Which of these is listed in 40 CFR 82.152 as a method for a follow-up verification test?
- Checking the nameplate
- Measuring compressor amperage
- Weighing the recovery cylinder after the repair
- Fluorescent dye and black lightCorrect answer
Why “Fluorescent dye and black light” is correct
The definition lists soap bubbles, electronic or ultrasonic leak detectors, pressure or vacuum tests, fluorescent dye and black light, infrared or near infrared tests, and handheld gas detection devices.
Source: 40 CFR 82.152
Why the other answers are wrong
- Checking the nameplate — The nameplate identifies the refrigerant but cannot verify a repair.
- Measuring compressor amperage — Amperage does not check whether a leak was repaired.
- Weighing the recovery cylinder after the repair — Cylinder weight does not test the repaired joint.
41. A low-side gauge on an R-22 system reads 0 psig. What is the absolute pressure at sea level?
- 0 psia
- 14.7 psiaCorrect answer
- 29.9 psia
- -14.7 psia
Why “14.7 psia” is correct
A gauge reads 0 at atmospheric pressure, which is about 14.7 psia at sea level. To convert any gauge reading to absolute pressure, add 14.7.
Source: EPA: Test Topics
Why the other answers are wrong
- 0 psia — 0 psia would be a perfect vacuum.
- 29.9 psia — 29.9 is atmospheric pressure in inches of mercury, not psi.
- -14.7 psia — Absolute pressure cannot be negative.
42. A technician needs to change the oil in a 75-pound R-22 system without pulling the whole system down. What does the rule allow?
- Draining the oil while the system is still at its operating pressure
- Draining it into a system receiver taken to 5 psig or lowerCorrect answer
- Draining the oil once the system is below 15 psig
- Adding nitrogen before draining the oil
Why “Draining it into a system receiver taken to 5 psig or lower” is correct
For oil changes, the technician may evacuate the appliance to no higher than 5 psig, or drain the oil into a system receiver that is evacuated or pressurized to no higher than 5 psig. Either way, the refrigerant dissolved in the oil is recovered.
Source: 40 CFR 82.156(a)(1)(iii); EPA: Service Practice Requirements
Why the other answers are wrong
- Draining the oil while the system is still at its operating pressure — Draining at operating pressure would release the refrigerant dissolved in the oil.
- Draining the oil once the system is below 15 psig — The limit is 5 psig, not 15.
- Adding nitrogen before draining the oil — Adding nitrogen does not meet the 5 psig requirement.
43. How may the full charge of a 400-pound R-22 commercial system be set using an established range from the best available data?
- The midpoint of the range is the full chargeCorrect answer
- The top of the range is the full charge
- The bottom of the range is the full charge
- The nameplate charge must always be used as the full charge
Why “The midpoint of the range is the full charge” is correct
Full charge may be set by the manufacturer's figure, by calculation, by actual measurements, or by an established range, in which case the midpoint of the range is the full charge. The owner must record the range, midpoint and how it was found.
Source: 40 CFR 82.152; 40 CFR 82.157(l)(1)
Why the other answers are wrong
- The top of the range is the full charge — The rule uses the midpoint, not the top.
- The bottom of the range is the full charge — The rule uses the midpoint, not the bottom.
- The nameplate charge must always be used as the full charge — The manufacturer's figure is only one of four allowed methods.
44. Why should liquid refrigerant never be trapped in a hose or line between two closed valves?
- The liquid will turn into oil
- It makes recovery machines lose certification
- Warming liquid expands and can burst the lineCorrect answer
- It changes the refrigerant's pressure class
Why “Warming liquid expands and can burst the line” is correct
Liquid refrigerant expands as it warms. With no vapor space to absorb the expansion, pressure in a liquid-full section rises sharply and can rupture a hose or line.
Source: EPA: Test Topics
Why the other answers are wrong
- The liquid will turn into oil — Refrigerant does not change into oil.
- It makes recovery machines lose certification — Equipment certification has nothing to do with trapped liquid.
- It changes the refrigerant's pressure class — Pressure class depends on the refrigerant, not on where it is trapped.
45. After the liquid has been recovered from a 180-pound R-410A system, what must still happen before the system is opened?
- Nothing; removing the liquid is enough
- The remaining vapor must also be recoveredCorrect answer
- The system must be charged with nitrogen to 50 psig
- The oil must be drained first
Why “The remaining vapor must also be recovered” is correct
Recovering liquid first only speeds the job. The rule requires all the refrigerant, liquid and vapor, to be evacuated to the Table 1 level, which for this high-pressure system under 200 pounds is 0 inches of Hg vacuum.
Source: 40 CFR 82.156(a); 40 CFR 82.156(a), Table 1; EPA: Test Topics
Why the other answers are wrong
- Nothing; removing the liquid is enough — Vapor left in the system would be released when it is opened.
- The system must be charged with nitrogen to 50 psig — Nitrogen does not replace recovering the refrigerant.
- The oil must be drained first — Draining oil is not required before every opening.
46. A light commercial air conditioner holds 20 pounds of R-410A and is part of the residential and light commercial air conditioning and heat pump subsector. Does the Part 84 leak repair rule apply?
- Yes, because it holds more than 15 pounds
- Yes, at the 10 percent comfort cooling rate
- No, because it holds less than 50 pounds
- No, that subsector is excludedCorrect answer
Why “No, that subsector is excluded” is correct
Part 84 leak repair covers HFC appliances of 15 pounds or more, but it expressly does not apply to appliances in the residential and light commercial air conditioning and heat pump subsector (40 CFR 84.106(a)(3)(ii)). The venting prohibition still applies.
Source: 40 CFR 84.106(a)
Why the other answers are wrong
- Yes, because it holds more than 15 pounds — The 15-pound threshold does not override the subsector exclusion.
- Yes, at the 10 percent comfort cooling rate — The comfort cooling rate does not apply to an excluded subsector.
- No, because it holds less than 50 pounds — 50 pounds is the Part 82 threshold, not the reason here.
47. Where is the filter-drier usually installed in an R-22 system, and what passes through it?
- In the liquid line, carrying high-pressure liquidCorrect answer
- In the discharge line, carrying hot vapor
- Between the evaporator and accumulator, carrying a liquid-vapor mix
- In the compressor crankcase, holding oil
Why “In the liquid line, carrying high-pressure liquid” is correct
The filter-drier is normally fitted in the liquid line ahead of the metering device. High-pressure liquid flows through it, and it traps moisture and debris before they reach the metering device.
Source: EPA: Test Topics
Why the other answers are wrong
- In the discharge line, carrying hot vapor — The discharge line is not where a liquid-line drier is fitted.
- Between the evaporator and accumulator, carrying a liquid-vapor mix — A suction-side location carries low-pressure vapor, not the main drier.
- In the compressor crankcase, holding oil — Driers are not installed inside the crankcase.
48. Why must the pressure relief valve on the liquid receiver of an R-22 system never be capped or plugged?
- It lets air into the system during evacuation
- It is used as a charging port
- It protects the receiver from bursting in a fireCorrect answer
- It meters liquid into the evaporator
Why “It protects the receiver from bursting in a fire” is correct
A relief valve opens to release pressure before a vessel can rupture, for example if the receiver is exposed to fire or overheating. Capping or plugging it removes that protection and turns the receiver into a potential bomb.
Source: EPA: Test Topics
Why the other answers are wrong
- It lets air into the system during evacuation — A relief valve is not an air inlet for evacuation.
- It is used as a charging port — Relief valves are not charging ports.
- It meters liquid into the evaporator — Metering liquid is the job of the expansion device.
49. When switching a recovery machine from R-22 to R-410A, what should be done with the machine's filter, if its manual calls for it?
- Leave it in place so it can catch any leftover R-22
- Vent it before reuse
- Rinse it with liquid R-410A
- Replace it before recovering the new refrigerantCorrect answer
Why “Replace it before recovering the new refrigerant” is correct
Recovery equipment must be used according to the manufacturer's directions. When the manual calls for a new filter at changeover, replacing it keeps the old refrigerant and contaminants from mixing into the new batch.
Source: 40 CFR 82.156(g); EPA: Test Topics
Why the other answers are wrong
- Leave it in place so it can catch any leftover R-22 — A filter holding old refrigerant can contaminate the next refrigerant.
- Vent it before reuse — Venting a filter releases refrigerant and is prohibited.
- Rinse it with liquid R-410A — Rinsing with refrigerant wastes refrigerant and is not a recognized practice.
50. A building owner services only their own appliances, which all have pump-out units. What exemption applies to them under 40 CFR 82.156?
- They need not use certified self-contained equipmentCorrect answer
- They do not need to be certified
- They may vent refrigerant from those appliances when servicing
- They need not evacuate before opening
Why “They need not use certified self-contained equipment” is correct
People who service or dispose of only appliances they own that contain pump-out units are exempt from the requirement to use certified, self-contained recovery and/or recycling equipment. They are not exempt from certification, evacuation levels or the venting ban.
Source: 40 CFR 82.156(f)
Why the other answers are wrong
- They do not need to be certified — The exemption covers equipment, not technician certification.
- They may vent refrigerant from those appliances when servicing — The venting prohibition still applies.
- They need not evacuate before opening — Evacuation requirements still apply before opening.
More EPA 608 practice
Read next
- EPA 608 Study Guide: Core, Type I, Type II and Type III: EPA does not publish a study guide for the Section 608 exam. It publishes a list of test topics. This guide works through that list section by section, explains what each topic is about, and gives the numbers from the regulation you need to know.
- How to Get EPA 608 Certified: EPA Section 608 certification is the federal credential you need to work on the refrigerant circuit of stationary air-conditioning and refrigeration equipment. Here is who needs it, how the tests work, how to pick a certification type, where and how to test, including online, and what happens after you pass.
Unofficial, not affiliated with the EPA or any EPA-approved certifying organization. Questions are original practice written from public EPA material, not real exam questions.