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EPA 608 universal practice test

A full 100-question mock of the Universal exam: 25 Core, 25 Type I, 25 Type II and 25 Type III questions, scored section by section.

Before you start

  • 100 questions: 25 Core, 25 Type 1, 25 Type 2, and 25 Type 3.
  • 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.
Start the test

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 I: Small appliances: factory-sealed with 5 pounds of refrigerant or less, like refrigerators, window units and dehumidifiers. Practice Type 1 questions.
  • Type II: Medium-, high- and very high-pressure appliances such as residential split systems, rooftop units and supermarket refrigeration. Practice Type 2 questions.
  • Type III: Low-pressure appliances, mainly centrifugal chillers using refrigerants like R-123 and R-11. Practice Type 3 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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

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.

This question on its own page

Type I

26. A water cooler holds 12 ounces of refrigerant and its compressor runs. Using recovery equipment made in 2008, how much must be recovered at minimum?
  • 10.8 ouncesCorrect answer
  • 9.6 ounces
  • 12 ounces
  • 8.4 ounces

Why “10.8 ounces” is correct

Equipment made on or after November 15, 1993 must recover 90 percent when the appliance compressor works. Ninety percent of 12 ounces is 10.8 ounces; evacuating to 4 inches of Hg vacuum would also satisfy the rule.

Source: 40 CFR 82.156(b)

Why the other answers are wrong

  • 9.6 ounces — That is 80 percent, which applies to older equipment or a compressor that is not working.
  • 12 ounces — The rule does not require the full charge.
  • 8.4 ounces — That is 70 percent, below any small-appliance level.

This question on its own page

27. A room air conditioner holds 2 pounds of refrigerant and its compressor runs. The recovery unit was made in 1992. How much must be recovered at minimum?
  • 1.6 poundsCorrect answer
  • 1.8 pounds
  • 2.0 pounds
  • 1.4 pounds

Why “1.6 pounds” is correct

Equipment made before November 15, 1993 must recover 80 percent whether or not the compressor runs, and 80 percent of 2 pounds is 1.6 pounds. A working compressor raises the target only for newer equipment.

Source: 40 CFR 82.156(b)

Why the other answers are wrong

  • 1.8 pounds — That is 90 percent, which applies only to equipment made on or after November 15, 1993.
  • 2.0 pounds — The rule does not require the full charge.
  • 1.4 pounds — That is 70 percent, below the required level.

This question on its own page

28. A commercial ice machine is factory-sealed with 6 pounds of R-404A. Which certification does a technician need to repair its sealed system?
  • Type I, because it was sealed at the factory
  • Type III, because ice machines are low-pressure
  • None, because ice machines are exempt
  • Type II, because it is over the 5-pound limitCorrect answer

Why “Type II, because it is over the 5-pound limit” is correct

A small appliance holds 5 pounds or less. At 6 pounds, this machine is a high-pressure appliance outside the small-appliance definition, and servicing it requires Type II certification, or Universal.

Source: 40 CFR 82.152; 40 CFR 82.161(a)

Why the other answers are wrong

  • Type I, because it was sealed at the factory — Factory sealing is not enough; the charge must also be 5 pounds or less.
  • Type III, because ice machines are low-pressure — R-404A is not a low-pressure refrigerant.
  • None, because ice machines are exempt — Ice machines with non-exempt refrigerants are covered by Section 608.

This question on its own page

29. How many questions does a Type I certification test contain?
  • 25 Core questions and 25 Type I questionsCorrect answer
  • 25 Type I questions only
  • 50 Type I questions only
  • 100 questions covering Core and all three types

Why “25 Core questions and 25 Type I questions” is correct

Appendix D says all Type I, Type II and Type III tests include 25 questions from Group I, the Core material, and 25 from the sector-specific group. A technician must pass both sections.

Source: 40 CFR Part 82 Subpart F, Appendix D

Why the other answers are wrong

  • 25 Type I questions only — Every Type test also includes 25 questions from the Core group.
  • 50 Type I questions only — The test is split between Core and Type I, 25 each.
  • 100 questions covering Core and all three types — One hundred questions is the size of a full Universal test.

This question on its own page

30. A technician takes the Universal test in one sitting. How many questions does it contain?
  • 75: 25 each for Types I, II and III, with no Core
  • 50: 25 Core and 25 mixed technical
  • 125: 50 Core and 25 for each type
  • 100: 25 Core and 25 each for Types I, II and IIICorrect answer

Why “100: 25 Core and 25 each for Types I, II and III” is correct

Appendix D says Universal tests include 100 questions: 25 from Group I and 25 from each of the three sector-specific areas. A Universal certification may also be built from passing scores on separate tests.

Source: 40 CFR Part 82 Subpart F, Appendix D

Why the other answers are wrong

  • 75: 25 each for Types I, II and III, with no Core — The Universal test also includes 25 Core questions.
  • 50: 25 Core and 25 mixed technical — Each of the three types gets its own 25 questions.
  • 125: 50 Core and 25 for each type — Core is 25 questions, not 50.

This question on its own page

31. A certifying program gives a Type I test. What must it do about the identity of the person taking it?
  • Nothing, if the test is taken by mail
  • Verify it, for example with a driver's license or passportCorrect answer
  • Accept the employer's word by phone
  • Check only the last four digits of the Social Security number

Why “Verify it, for example with a driver's license or passport” is correct

Appendix D says each Type I test must provide a means of verifying the identification of the person taking it, and lists drivers' licenses and passports as acceptable forms.

Source: 40 CFR Part 82 Subpart F, Appendix D

Why the other answers are wrong

  • Nothing, if the test is taken by mail — Appendix D requires identity checks for every Type I test, mail-in included.
  • Accept the employer's word by phone — An employer's phone call is not one of the forms of ID named.
  • Check only the last four digits of the Social Security number — The card number may not include a Social Security number, and photo ID is the named method.

This question on its own page

32. Must a scrap recycler that disposes of small appliances certify to its EPA Regional Office that it owns and uses certified recovery equipment?
  • Yes, once every three years
  • No, EPA no longer requires that certificationCorrect answer
  • Yes, before accepting its first appliance
  • Only if it recovers more than 100 appliances a year

Why “No, EPA no longer requires that certification” is correct

EPA's safe disposal guidance states it no longer requires persons involved in the final disposal of appliances to certify to their Regional Office that they have and properly use certified recovery equipment. The recovery and verification duties still apply.

Source: EPA: Safe Disposal Requirements

Why the other answers are wrong

  • Yes, once every three years — EPA has dropped this requirement for persons involved in final disposal.
  • Yes, before accepting its first appliance — EPA no longer requires the Regional Office certification at all.
  • Only if it recovers more than 100 appliances a year — There is no volume-based version of this requirement.

This question on its own page

33. Which appliance usually enters the waste stream with its refrigerant charge intact, so the final-processor rules apply?
  • A window air conditionerCorrect answer
  • A centrifugal chiller
  • A central residential air conditioner
  • A supermarket refrigeration system

Why “A window air conditioner” is correct

EPA lists household refrigerators and freezers, window air conditioners and MVACs as equipment that typically enters the waste stream with its charge intact. For these, the final person in the disposal chain must recover the refrigerant or verify that it was recovered.

Source: EPA: Safe Disposal Requirements

Why the other answers are wrong

  • A centrifugal chiller — Chillers are usually dismantled on site, with refrigerant recovered under the servicing rules.
  • A central residential air conditioner — EPA lists central residential AC as equipment typically dismantled on site.
  • A supermarket refrigeration system — Retail food systems are typically dismantled on site before disposal.

This question on its own page

34. Recovery equipment will be used only to remove refrigerant from small appliances before they are scrapped. Which test can it pass to be certified?
  • Reaching 25 mm Hg absolute on a calibrated micron gauge
  • Recovering 100 percent of a test charge
  • Reaching a 4-inch vacuum on a properly calibrated gaugeCorrect answer
  • Reaching 0 psig within 10 minutes

Why “Reaching a 4-inch vacuum on a properly calibrated gauge” is correct

Section 82.158(e)(5) says equipment used to evacuate refrigerant from small appliances before disposal may also be certified if it can achieve a four-inch vacuum when tested with a properly calibrated pressure gauge.

Source: 40 CFR 82.158(e)

Why the other answers are wrong

  • Reaching 25 mm Hg absolute on a calibrated micron gauge — That level belongs to low-pressure appliances, not small-appliance disposal equipment.
  • Recovering 100 percent of a test charge — No certification standard requires complete recovery.
  • Reaching 0 psig within 10 minutes — No timed test of this kind is in the rule.

This question on its own page

35. A worker removes refrigerant from a scrapped dehumidifier before disposal. To what level must the refrigerant be recovered?
  • No set level, because no certification is required for disposal
  • The same 80 or 90 percent, or 4-inch vacuum, used for serviceCorrect answer
  • Down to 0 psig
  • Down to 10 inches of Hg vacuum

Why “The same 80 or 90 percent, or 4-inch vacuum, used for service” is correct

Section 82.155(a) says persons recovering refrigerant from a small appliance for disposal must evacuate it to the levels in 82.156(b). Those are the same levels a technician must meet before opening the appliance for service.

Source: 40 CFR 82.155(a); 40 CFR 82.156(b)

Why the other answers are wrong

  • No set level, because no certification is required for disposal — Disposal does not need certification, but 82.155(a) still sets the levels.
  • Down to 0 psig — Zero psig is not the small-appliance disposal level.
  • Down to 10 inches of Hg vacuum — Ten inches is a Table 1 level for some larger appliances.

This question on its own page

36. A building engineer on a company's in-house staff wants to add refrigerant to a break-room vending machine. Does the engineer need certification?
  • No, because in-house staff are not counted as technicians
  • No, because the machine is under 5 pounds
  • Yes, but only Section 609 certification
  • Yes, Type I or Universal, since this is technician workCorrect answer

Why “Yes, Type I or Universal, since this is technician work” is correct

Under 82.152, adding or removing refrigerant is an activity that violates the integrity of the refrigerant circuit, and technicians include in-house service personnel. Persons servicing small appliances must be certified as Type I.

Source: 40 CFR 82.152; 40 CFR 82.161(a)

Why the other answers are wrong

  • No, because in-house staff are not counted as technicians — The technician definition expressly includes in-house service personnel.
  • No, because the machine is under 5 pounds — A charge under 5 pounds makes it a small appliance, which requires Type I to service; only disposal is exempt from certification.
  • Yes, but only Section 609 certification — Section 609 covers motor vehicle air conditioning, not vending machines.

This question on its own page

37. A technician finds a solderless piercing valve left on a refrigerator's process stub from an earlier repair. The unit is now low on charge. What is a likely cause?
  • The refrigerant has worn out with age
  • The thermostat has been set too warm
  • The old piercing valve has been slowly leakingCorrect answer
  • The process stub is designed to bleed off pressure

Why “The old piercing valve has been slowly leaking” is correct

Solderless access fittings are not a permanent seal and tend to leak over time, which is why EPA's test topics say to remove them at the end of service. A fitting left in place is a prime suspect when a sealed system loses charge.

Source: EPA: Test Topics

Why the other answers are wrong

  • The refrigerant has worn out with age — Refrigerant does not wear out or get used up in a sealed system; a low charge means a leak.
  • The thermostat has been set too warm — A thermostat setting cannot remove refrigerant from the system.
  • The process stub is designed to bleed off pressure — A process stub is resealed after service and is not meant to release refrigerant.

This question on its own page

38. A passive recovery device is connected to a dehumidifier that still works, but the unit is switched off and recovery is slow. What should the technician do?
  • Leave it off and heat the cabinet
  • Open the low side to the air
  • Add refrigerant to raise the system pressure first
  • Switch the dehumidifier on so its compressor runsCorrect answer

Why “Switch the dehumidifier on so its compressor runs” is correct

EPA's test topics call for operating an operative compressor when using a system-dependent device. The running compressor pushes refrigerant toward the recovery container far better than the device can alone.

Source: EPA: Test Topics

Why the other answers are wrong

  • Leave it off and heat the cabinet — Heating is an aid for a compressor that cannot run; this one can.
  • Open the low side to the air — That would vent refrigerant and let in air.
  • Add refrigerant to raise the system pressure first — Adding refrigerant during recovery is pointless and wasteful.

This question on its own page

39. Which two readings does a technician need to check a refrigerant against a pressure-temperature chart?
  • The refrigerant's pressure and its temperatureCorrect answer
  • Its pressure and the charge weight
  • Its temperature and the compressor's running amp draw
  • Its superheat and its subcooling

Why “The refrigerant's pressure and its temperature” is correct

A P/T chart lists the saturation pressure of each refrigerant at each temperature. Measuring both pressure and temperature lets the technician compare the reading with the chart to identify the refrigerant or spot noncondensables.

Source: EPA: Test Topics

Why the other answers are wrong

  • Its pressure and the charge weight — A P/T chart does not use charge weight.
  • Its temperature and the compressor's running amp draw — Amp draw is an electrical reading, not a chart value.
  • Its superheat and its subcooling — Superheat and subcooling are derived from P/T readings; they are not the two readings used to enter the chart.

This question on its own page

40. Why does warming and tapping a dead compressor help recovery from a small appliance?
  • It restarts the compressor motor
  • It seals small leaks in the compressor shell welds
  • Refrigerant in the oil is driven out as vaporCorrect answer
  • It turns noncondensables into liquid

Why “Refrigerant in the oil is driven out as vapor” is correct

Compressor oil holds dissolved refrigerant. Warming the oil and jarring the compressor release that refrigerant as vapor so it can be drawn out, which is why EPA's test topics list heating and sharply striking the compressor.

Source: EPA: Test Topics

Why the other answers are wrong

  • It restarts the compressor motor — Heat and tapping are used because the compressor will not run.
  • It seals small leaks in the compressor shell welds — Heat and tapping do not repair leaks.
  • It turns noncondensables into liquid — Noncondensables do not condense under these conditions.

This question on its own page

41. When a working compressor is run during passive recovery, where does it move most of the refrigerant?
  • Into the evaporator, where it stays trapped
  • Out through the process stub to the air
  • Back into the compressor oil
  • To the high side, where it can be capturedCorrect answer

Why “To the high side, where it can be captured” is correct

A running compressor draws refrigerant from the low side and discharges it into the condenser on the high side. A passive device connected there can capture it, which is why running an operative compressor improves recovery.

Source: EPA: Test Topics

Why the other answers are wrong

  • Into the evaporator, where it stays trapped — The compressor pulls refrigerant out of the low side and discharges it to the high side.
  • Out through the process stub to the air — A properly connected device captures it; nothing should be released.
  • Back into the compressor oil — Running the compressor drives refrigerant out of the oil, not into it.

This question on its own page

42. Which gauge would a technician read to confirm a small appliance has reached 4 inches of Hg vacuum?
  • The high-side pressure gauge
  • The recovery cylinder's scale
  • The appliance's thermostat dial
  • The low-side compound gaugeCorrect answer

Why “The low-side compound gauge” is correct

A compound gauge reads both pressure above atmosphere and vacuum in inches of mercury below it. Confirming the 4-inch option in 82.156(b)(3) is a vacuum reading, so the compound gauge is used.

Source: EPA: Test Topics; 40 CFR 82.156(b)

Why the other answers are wrong

  • The high-side pressure gauge — A high-side gauge usually reads only positive pressure, not inches of vacuum.
  • The recovery cylinder's scale — A scale reads weight, not vacuum.
  • The appliance's thermostat dial — A thermostat setting has nothing to do with system pressure.

This question on its own page

43. A refrigerator's nameplate charge is 9 ounces, and the compressor works. How can the technician confirm the 90 percent level was met with newer equipment?
  • Check that all the frost has melted off the evaporator coil
  • Run the recovery for 20 minutes and stop
  • Weigh what was recovered: it must be at least 8.1 ouncesCorrect answer
  • Check that the high side reads 0 psig

Why “Weigh what was recovered: it must be at least 8.1 ounces” is correct

Ninety percent of a 9-ounce charge is 8.1 ounces, so weighing the recovered refrigerant against the nameplate charge shows whether the level was met. The technician may instead evacuate to 4 inches of Hg vacuum.

Source: 40 CFR 82.156(b)

Why the other answers are wrong

  • Check that all the frost has melted off the evaporator coil — Frost tells you nothing about how much refrigerant was recovered.
  • Run the recovery for 20 minutes and stop — A fixed time does not prove a recovery level.
  • Check that the high side reads 0 psig — Zero psig does not equal 90 percent recovery or the 4-inch option.

This question on its own page

44. Does the advice to tap both the high and low sides of a small appliance with a dead compressor apply only to passive devices?
  • Yes, self-contained machines never need high-side access valves
  • No, it applies to any recovery when the compressor won't runCorrect answer
  • Yes, because passive devices are the only type allowed
  • No, it applies only to appliances over 5 pounds

Why “No, it applies to any recovery when the compressor won't run” is correct

EPA's test topics state the need to install both high- and low-side access valves when recovering from small appliances with inoperative compressors, without limiting it to one equipment type. The problem is refrigerant trapped in the system, whatever pulls it out.

Source: EPA: Test Topics

Why the other answers are wrong

  • Yes, self-contained machines never need high-side access valves — A self-contained machine still cannot pull trapped refrigerant through a stopped compressor quickly.
  • Yes, because passive devices are the only type allowed — Both self-contained and system-dependent equipment may be used on small appliances.
  • No, it applies only to appliances over 5 pounds — The advice is specifically about small appliances with inoperative compressors.

This question on its own page

45. A window unit charged with R-134a is leaking near a torch. Which decomposition product is the main concern?
  • Hydrochloric acid
  • Sulfuric acid
  • Hydrofluoric acidCorrect answer
  • Nitric acid

Why “Hydrofluoric acid” is correct

R-134a is an HFC made of hydrogen, fluorine and carbon. At flame temperatures its fluorine can form hydrofluoric acid; phosgene and hydrochloric acid need chlorine, which R-134a does not have.

Source: EPA: Test Topics

Why the other answers are wrong

  • Hydrochloric acid — Hydrochloric acid comes from chlorine, and R-134a contains none.
  • Sulfuric acid — R-134a contains no sulfur.
  • Nitric acid — R-134a contains no nitrogen.

This question on its own page

46. Which of these refrigerants can form phosgene and hydrochloric acid when it decomposes in a flame?
  • R-12Correct answer
  • R-134a
  • R-600a
  • R-744 (carbon dioxide)

Why “R-12” is correct

Phosgene and hydrochloric acid both contain chlorine, so only chlorine-containing refrigerants such as CFCs and HCFCs can form them. R-12 is a CFC, which makes it the one here.

Source: EPA: Test Topics

Why the other answers are wrong

  • R-134a — R-134a has no chlorine, so it cannot form phosgene or hydrochloric acid.
  • R-600a — Isobutane is a hydrocarbon and burns to carbon dioxide and water.
  • R-744 (carbon dioxide) — Carbon dioxide contains no chlorine.

This question on its own page

47. A refrigerator with a refrigerant leak sits next to a gas water heater with a pilot light. Why is this a hazard?
  • Leaking refrigerant drawn into the flame can form toxic gasesCorrect answer
  • The refrigerant will make the pilot burn hotter
  • The pilot will freeze from the cold refrigerant
  • There is no hazard, as refrigerants are nontoxic in any amount

Why “Leaking refrigerant drawn into the flame can form toxic gases” is correct

Any open flame, including a pilot light, can decompose refrigerant vapor that drifts into it. The result can include hydrochloric acid, hydrofluoric acid and, for chlorine-containing refrigerants, phosgene.

Source: EPA: Test Topics

Why the other answers are wrong

  • The refrigerant will make the pilot burn hotter — The main danger is toxic decomposition, not a hotter pilot.
  • The pilot will freeze from the cold refrigerant — A small leak does not freeze a pilot flame.
  • There is no hazard, as refrigerants are nontoxic in any amount — Low-toxicity refrigerants can still form highly toxic products in a flame.

This question on its own page

48. A portable air conditioner uses R-32, a mildly flammable refrigerant. What kind of recovery equipment should be used on it?
  • Any small-appliance recovery unit already certified for R-134a
  • Equipment certified for use with flammable refrigerantsCorrect answer
  • A homemade pump with a spark-proof switch
  • No equipment, because R-32 may be vented

Why “Equipment certified for use with flammable refrigerants” is correct

Section 82.154(b)(2) requires recovery equipment certified for that type of refrigerant and appliance. Under 82.158(e)(4), newer equipment is tested under appendix B3 for non-flammable refrigerants or appendix B4, based on AHRI 740-2016 and UL 1963 Supplement SB, for flammable refrigerants, so a flammable refrigerant such as R-32 calls for equipment certified for that use.

Source: 40 CFR 82.154(b); 40 CFR 82.158(e)

Why the other answers are wrong

  • Any small-appliance recovery unit already certified for R-134a — Equipment for non-flammable refrigerants is tested under a different appendix.
  • A homemade pump with a spark-proof switch — Recovery equipment must be certified, and a homemade rig is not.
  • No equipment, because R-32 may be vented — R-32 is not on the list of exempt substitutes in 82.154(a).

This question on its own page

49. A technician must open the tubing of a household refrigerator that uses R-290. Why use a tubing cutter instead of a torch?
  • A torch would freeze the tubing
  • A flame could ignite any propane left in the systemCorrect answer
  • Tubing cutters are required on every appliance by law
  • Propane makes copper too hard to braze

Why “A flame could ignite any propane left in the system” is correct

R-290 is propane, a flammable hydrocarbon. Any refrigerant left in the tubing could ignite if exposed to an open flame, so the system is opened with a cutter and ignition sources are kept away.

Source: EPA: Test Topics; 40 CFR 82.154(a)

Why the other answers are wrong

  • A torch would freeze the tubing — A torch heats tubing; it does not freeze it.
  • Tubing cutters are required on every appliance by law — The reason is the flammable refrigerant, not a general legal rule.
  • Propane makes copper too hard to braze — The hazard is fire, not the copper's hardness.

This question on its own page

50. Most refrigerants used in small appliances are low in toxicity. Why is a refrigerant leak near a flame still dangerous?
  • The flame makes the refrigerant radioactive
  • The refrigerant puts out the flame and causes an explosion
  • Its decomposition products are far more toxic than the refrigerantCorrect answer
  • It isn't dangerous, since the refrigerant is low in toxicity anyway

Why “Its decomposition products are far more toxic than the refrigerant” is correct

EPA's test topics list decomposition products of refrigerants at high temperatures as a Type I safety topic. Acids and, for chlorine-containing refrigerants, phosgene are far more harmful than the refrigerant itself.

Source: EPA: Test Topics

Why the other answers are wrong

  • The flame makes the refrigerant radioactive — Refrigerants do not become radioactive.
  • The refrigerant puts out the flame and causes an explosion — That is not how decomposition works; the issue is toxic gases.
  • It isn't dangerous, since the refrigerant is low in toxicity anyway — Low toxicity in normal use does not hold once the refrigerant breaks down.

This question on its own page

Type II

51. 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.

This question on its own page

52. 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.

This question on its own page

53. 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.

This question on its own page

54. 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.

This question on its own page

55. 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.

This question on its own page

56. 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.

This question on its own page

57. 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.

This question on its own page

58. 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.

This question on its own page

59. 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.

This question on its own page

60. 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.

This question on its own page

61. 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.

This question on its own page

62. 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.

This question on its own page

63. 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.

This question on its own page

64. 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.

This question on its own page

65. 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.

This question on its own page

66. 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.

This question on its own page

67. 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.

This question on its own page

68. 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.

This question on its own page

69. 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.

This question on its own page

70. 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.

This question on its own page

71. 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.

This question on its own page

72. 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.

This question on its own page

73. 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.

This question on its own page

74. 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.

This question on its own page

75. 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.

This question on its own page

Type III

76. A technician must bring an R-113 machine up to atmospheric pressure for a non-major repair. Which procedure follows 40 CFR 82.156(a)(1)(ii)?
  • Use nitrogen alone, since R-113 is exempt from the heat requirement
  • Use heat only, because nitrogen is never allowed on low-pressure machines
  • Use compressed air to reach atmospheric, then purge before opening
  • Heat it as far as heat will go, then add nitrogen up to atmosphericCorrect answer

Why “Heat it as far as heat will go, then add nitrogen up to atmospheric” is correct

For low-pressure refrigerants that boil above 85 °F at atmospheric pressure, such as R-113, the rule requires heat to raise internal pressure as much as possible. Nitrogen may then be used only to bring the pressure from that point up to atmospheric.

Source: 40 CFR 82.156(a)(1)(ii)

Why the other answers are wrong

  • Use nitrogen alone, since R-113 is exempt from the heat requirement — Heat must be used first, as much as possible, before any nitrogen is added.
  • Use heat only, because nitrogen is never allowed on low-pressure machines — Nitrogen is allowed on R-113 machines to make up the last of the pressure after heat.
  • Use compressed air to reach atmospheric, then purge before opening — Air is not an allowed method and would contaminate the refrigerant.

This question on its own page

77. An R-123 chiller is pulled down to 25 mm Hg absolute, then the pressure creeps up after the recovery unit is valved off. What should the technician do next?
  • Open the chiller, since the shell is still well under a vacuum anyway
  • Resume recovery until the pressure holds at the required levelCorrect answer
  • Break the vacuum with nitrogen and start the repair
  • Log the reading and leave the chiller as it is

Why “Resume recovery until the pressure holds at the required level” is correct

A pressure rise after recovery stops means liquid refrigerant is still present in the chiller or its oil. The technician should restart recovery and repeat the wait-and-watch check until the pressure stays at 25 mm Hg absolute.

Source: EPA: Test Topics; 40 CFR 82.156(a)

Why the other answers are wrong

  • Open the chiller, since the shell is still well under a vacuum anyway — The chiller has not held the required level, so it is not ready to open.
  • Break the vacuum with nitrogen and start the repair — The rising pressure shows refrigerant is still in the chiller, so breaking the vacuum now would be premature.
  • Log the reading and leave the chiller as it is — Logging the rise does not recover the refrigerant still in the chiller.

This question on its own page

78. A technician's micron gauge is used to confirm the evacuation of an R-11 chiller. Roughly what reading equals the 25 mm Hg absolute level in Table 1?
  • 500 microns
  • 25,000 micronsCorrect answer
  • 2,500 microns
  • 250,000 microns

Why “25,000 microns” is correct

A micron is one-thousandth of a millimetre of mercury, measured from a perfect vacuum. 25 mm Hg absolute is therefore 25,000 microns, the level a low-pressure appliance must reach before it is opened or disposed of.

Source: 40 CFR 82.156(a), Table 1; EPA: Test Topics

Why the other answers are wrong

  • 500 microns — 500 microns is a common dehydration target and is far deeper than the Table 1 recovery level.
  • 2,500 microns — This is off by a factor of ten; 1 mm Hg equals 1,000 microns.
  • 250,000 microns — This is off by a factor of ten in the other direction.

This question on its own page

79. A technician pulls the vapor space of an R-123 chiller to 25 mm Hg absolute, but liquid is still pooled in the bottom of the evaporator. Has the evacuation requirement been met?
  • No; the refrigerant must be evacuated, including all the liquidCorrect answer
  • Yes; the rule measures the vapor pressure only, not the liquid level
  • Yes, if the liquid amount is under 200 pounds
  • Only if the recovery unit was made after 1993

Why “No; the refrigerant must be evacuated, including all the liquid” is correct

40 CFR 82.156(a) requires technicians to evacuate the refrigerant, including all the liquid refrigerant, to the Table 1 level. A momentary reading over pooled liquid will not hold, because the liquid keeps boiling off and raising the pressure.

Source: 40 CFR 82.156(a)

Why the other answers are wrong

  • Yes; the rule measures the vapor pressure only, not the liquid level — The rule names liquid refrigerant specifically; pooled liquid must be removed.
  • Yes, if the liquid amount is under 200 pounds — There is no allowance for leaving liquid behind, whatever the amount.
  • Only if the recovery unit was made after 1993 — The equipment date does not change the requirement to remove the liquid.

This question on its own page

80. An R-11 chiller has a leaking evaporator that cannot reach Table 1 levels. Under the leaky-appliance rule, what is the first thing the technician should do?
  • Evacuate the whole chiller to 0 psig and open it
  • Isolate leaking components from non-leaking ones where possibleCorrect answer
  • Pressurize the whole chiller with nitrogen to locate the leak first
  • Vent the remaining vapor because it is contaminated

Why “Isolate leaking components from non-leaking ones where possible” is correct

40 CFR 82.156(a)(2) starts by asking the technician to isolate leaking from non-leaking components wherever possible. The non-leaking parts then go to the Table 1 level and the leaking parts to the lowest level attainable without substantial contamination, never above 0 psig.

Source: 40 CFR 82.156(a)(2)

Why the other answers are wrong

  • Evacuate the whole chiller to 0 psig and open it — Non-leaking parts must still reach Table 1 levels, so the whole chiller cannot simply be taken to 0 psig.
  • Pressurize the whole chiller with nitrogen to locate the leak first — The rule's first step is isolating leaking components, and adding nitrogen would contaminate the refrigerant still to be recovered.
  • Vent the remaining vapor because it is contaminated — Venting refrigerant is prohibited; contaminated refrigerant is still recovered.

This question on its own page

81. Hot water in the tubes has raised an idle R-11 chiller only to atmospheric pressure, which is not enough for a leak test. What is the accepted next step?
  • Add nitrogen until the pressure reaches about 25 psig for a stronger test
  • Add nitrogen through a regulator, staying at or under 10 psigCorrect answer
  • Add compressed air through the purge connection
  • Run the compressor to build pressure in the shell

Why “Add nitrogen through a regulator, staying at or under 10 psig” is correct

EPA lists nitrogen as the second choice for pressurizing a low-pressure system for leak testing, after heating. When nitrogen is used, it goes in through a pressure regulator and the test pressure is kept at or below 10 psig, or the manufacturer's lower limit (Trane specifies 8 psig), to protect the rupture disc.

Source: EPA: Test Topics; Trane CTV-SVX05H-EN, R-123 handling guide (8 psig leak test)

Why the other answers are wrong

  • Add nitrogen until the pressure reaches about 25 psig for a stronger test — 25 psig is far above the safe limit and risks the rupture disc.
  • Add compressed air through the purge connection — Compressed air is not an acceptable leak test gas.
  • Run the compressor to build pressure in the shell — The compressor does not raise standing pressure in the shell for a leak test.

This question on its own page

82. A 650-pound R-11 chiller that cools a chemical process exceeds the 30% leak rate. How often must leak inspections be done?
  • Once per calendar year, until a full year of calculations is under the rate
  • Once a month, until the chiller is retrofitted
  • Every six months, until two inspections find no leaks
  • Every three months, until four quarters in a row are under the rateCorrect answer

Why “Every three months, until four quarters in a row are under the rate” is correct

Industrial process refrigeration and commercial refrigeration appliances with 500 pounds or more must have a leak inspection once every three months after exceeding their leak rate. Inspections continue until leak rate calculations show four quarters in a row under the rate.

Source: 40 CFR 82.157(g)

Why the other answers are wrong

  • Once per calendar year, until a full year of calculations is under the rate — Annual inspections apply to smaller IPR and commercial systems and to comfort cooling.
  • Once a month, until the chiller is retrofitted — The rule does not set a monthly schedule.
  • Every six months, until two inspections find no leaks — Semiannual inspections are not part of 40 CFR 82.157(g).

This question on its own page

83. An automatic leak detection system that senses R-123 in the equipment-room air is used in place of leak inspections. At what concentration must it alert the owner?
  • 10 parts per million
  • 50 parts per million
  • 1,000 parts per million
  • 100 parts per millionCorrect answer

Why “100 parts per million” is correct

A system that detects refrigerant in air must accurately sense 10 ppm of the refrigerant and alert the owner when the concentration reaches 100 ppm. Its sensors must sit close to the compressor, evaporator, condenser and other likely leak points inside an enclosed building.

Source: 40 CFR 82.157(g)

Why the other answers are wrong

  • 10 parts per million — 10 ppm is the level the system must be able to detect accurately, not the alert level.
  • 50 parts per million — 50 ppm is not a figure in the rule.
  • 1,000 parts per million — 1,000 ppm is ten times higher than the required alert level.

This question on its own page

84. After a required leak inspection on an R-123 chiller, what must the technician's documentation to the owner include?
  • The lot number and AHRI 700 test result of any reclaimed refrigerant used
  • A signature from an EPA regional official
  • The technician's certification test score
  • A certification that all visible and accessible parts were inspectedCorrect answer

Why “A certification that all visible and accessible parts were inspected” is correct

Leak inspection records must show the date, the method used, the location of each leak found, and a certification that all visible and accessible parts of the appliance were inspected. The technician provides this to the owner, who keeps it.

Source: 40 CFR 82.157(l)

Why the other answers are wrong

  • The lot number and AHRI 700 test result of any reclaimed refrigerant used — Reclaim lot numbers are not part of the leak inspection record.
  • A signature from an EPA regional official — EPA does not sign leak inspection records.
  • The technician's certification test score — Test scores are not part of the inspection record.

This question on its own page

85. A 500-pound R-11 chiller serves an industrial process. Roughly how much refrigerant would it have to lose over 12 months to exceed its leak rate?
  • More than 50 pounds
  • More than 100 pounds
  • More than 150 poundsCorrect answer
  • More than 625 pounds

Why “More than 150 pounds” is correct

Industrial process refrigeration has a 30 percent leak rate, and the leak rate is the share of full charge that would be lost over 12 months. Thirty percent of 500 pounds is 150 pounds.

Source: 40 CFR 82.157(c); EPA: Leak Repair Requirements

Why the other answers are wrong

  • More than 50 pounds — 50 pounds would be the 10 percent comfort cooling threshold for this charge.
  • More than 100 pounds — 100 pounds would be the 20 percent commercial refrigeration threshold.
  • More than 625 pounds — 625 pounds is 125 percent, the chronic leaker reporting level.

This question on its own page

86. A replacement part for a leaking R-123 comfort chiller is not available within 30 days. If the owner meets the extension conditions, what is the longest the repair can be delayed?
  • 60 days after delivery, with no overall limit
  • Until the next cooling season begins
  • 30 days after delivery, but not over 180 days totalCorrect answer
  • 30 days after delivery, but not over 270 days total

Why “30 days after delivery, but not over 180 days total” is correct

When parts are not available, 40 CFR 82.157(f) allows up to 30 days after delivery of the needed components, not to exceed 180 days from when the appliance exceeded its leak rate. The cap is 270 days only when an industrial process shutdown is needed, and the owner must request the extension from EPA.

Source: 40 CFR 82.157(f)

Why the other answers are wrong

  • 60 days after delivery, with no overall limit — The extension is 30 days after delivery and is capped.
  • Until the next cooling season begins — The rule ties the extension to part delivery, not to the season.
  • 30 days after delivery, but not over 270 days total — 270 days is the cap only when an industrial process shutdown is required.

This question on its own page

87. An owner wrote a retrofit plan for a leaking R-11 chiller but then got the leaks under control. To ask EPA for relief from retrofitting, by when must the owner show the chiller no longer exceeds its leak rate?
  • Within 30 days of the plan's date
  • Within 180 days of the plan's dateCorrect answer
  • Within one year of the plan's date
  • Within 10 days of the plan's date

Why “Within 180 days of the plan's date” is correct

40 CFR 82.157(h)(5)(ii) lets an owner ask to be relieved of a retrofit or retirement plan if, within 180 days of the plan's date, it can show the appliance no longer exceeds its leak rate. The owner must also agree in writing to repair all identified leaks within one year of the plan date.

Source: 40 CFR 82.157(h); EPA: Leak Repair Requirements

Why the other answers are wrong

  • Within 30 days of the plan's date — 30 days is when the plan must be written, not the relief window.
  • Within one year of the plan's date — One year is the deadline for finishing the plan's work.
  • Within 10 days of the plan's date — 10 days is the follow-up verification test window.

This question on its own page

88. How long must the owner of a 300-pound R-123 chiller keep its service and leak inspection records?
  • At least three yearsCorrect answer
  • At least one year
  • At least five years
  • Until the next chiller overhaul

Why “At least three years” is correct

40 CFR 82.157(l) requires that leak repair records be kept for at least three years, in paper or electronic form, unless another period is stated. Full-charge records are kept until three years after the appliance is retired.

Source: 40 CFR 82.157(l)

Why the other answers are wrong

  • At least one year — One year is too short; the rule says three years.
  • At least five years — Five years is longer than the general Part 82 requirement.
  • Until the next chiller overhaul — Retention is set in years, not by service events.

This question on its own page

89. Why does removing liquid at the start of recovery from an R-11 chiller save time?
  • Liquid recovery needs no certified equipment
  • Liquid recovery skips the 25 mm Hg requirement
  • Liquid moves far more refrigerant per minute than vaporCorrect answer
  • Liquid leaves the oil behind, along with all the refrigerant dissolved in it

Why “Liquid moves far more refrigerant per minute than vapor” is correct

A pound of liquid takes up far less volume than a pound of vapor, so pulling the liquid first moves most of the charge quickly. Vapor recovery then handles what is left.

Source: EPA: Test Topics

Why the other answers are wrong

  • Liquid recovery needs no certified equipment — Certified equipment is required whether liquid or vapor is recovered.
  • Liquid recovery skips the 25 mm Hg requirement — The chiller must still reach 25 mm Hg absolute.
  • Liquid leaves the oil behind, along with all the refrigerant dissolved in it — Leaving refrigerant in the oil does not save time; it has to be recovered too.

This question on its own page

90. The chilled-water pump on an R-123 chiller cannot run while the refrigerant is being recovered. How can the technician protect the tubes from freezing?
  • Add antifreeze to the refrigerant
  • Speed up recovery to finish faster
  • Drain the water from the tubesCorrect answer
  • Close the water valves and leave the water in place

Why “Drain the water from the tubes” is correct

EPA's test topics list two ways to prevent freezing during evacuation: circulate the water or remove it. If the water cannot be circulated, draining the tubes removes the risk.

Source: EPA: Test Topics

Why the other answers are wrong

  • Add antifreeze to the refrigerant — Nothing should be added to the refrigerant; the water side is what needs attention.
  • Speed up recovery to finish faster — Faster recovery cools the refrigerant faster and makes freezing more likely.
  • Close the water valves and leave the water in place — Stagnant water in the tubes is exactly what freezes.

This question on its own page

91. Which order of steps is correct when recovering refrigerant from an R-11 chiller before a major repair?
  • Recover liquid, then vapor, then wait to see if pressure risesCorrect answer
  • Recover vapor, then liquid, then open the chiller
  • Recover liquid only, then open the chiller once it reaches 0 psig
  • Recover vapor, add nitrogen, then recover liquid

Why “Recover liquid, then vapor, then wait to see if pressure rises” is correct

Removing the liquid first gets most of the charge out fastest. Vapor recovery then pulls the chiller to 25 mm Hg absolute, and a few minutes' wait shows whether liquid is still boiling off before the chiller is opened.

Source: EPA: Test Topics; 40 CFR 82.156(a)

Why the other answers are wrong

  • Recover vapor, then liquid, then open the chiller — Liquid should come first, and the pressure must be checked before opening.
  • Recover liquid only, then open the chiller once it reaches 0 psig — A major repair needs 25 mm Hg absolute, which takes vapor recovery as well.
  • Recover vapor, add nitrogen, then recover liquid — Nitrogen is not part of recovery, and liquid should come out before vapor.

This question on its own page

92. A technician is charging vapor into an evacuated R-11 chiller. At what point is it safe to switch to charging liquid?
  • When the pressure is above the saturation pressure for 32 °FCorrect answer
  • When the shell pressure reaches 0 psig
  • After exactly 10 pounds of vapor have gone in
  • As soon as the purge unit starts running

Why “When the pressure is above the saturation pressure for 32 °F” is correct

Liquid will not boil below freezing once the chiller pressure is above the saturation pressure that matches 32 °F. Until then, vapor is charged; after that, liquid can be added without freezing the water in the tubes.

Source: EPA: Test Topics

Why the other answers are wrong

  • When the shell pressure reaches 0 psig — Liquid can be safely added well before atmospheric pressure, once the 32 °F point is passed.
  • After exactly 10 pounds of vapor have gone in — The switch point depends on pressure, not a fixed weight.
  • As soon as the purge unit starts running — Purge operation does not tell you when liquid charging is safe.

This question on its own page

93. Which plan is correct for charging 600 pounds of R-123 into an evacuated centrifugal chiller?
  • Charge vapor, then liquid, through the evaporator charging valve with water flowingCorrect answer
  • Charge liquid, then vapor, through the condenser relief connection with the pumps off
  • Charge liquid only, through the purge unit, with water drained
  • Charge vapor only, through the compressor discharge, with pumps off

Why “Charge vapor, then liquid, through the evaporator charging valve with water flowing” is correct

EPA's test topics combine two charging points for centrifugals: introduce vapor before liquid to keep tube water from freezing, and charge through the evaporator charging valve. Keeping water circulating adds another layer of protection.

Source: EPA: Test Topics

Why the other answers are wrong

  • Charge liquid, then vapor, through the condenser relief connection with the pumps off — Liquid first risks freezing, and still water in the tubes makes it worse.
  • Charge liquid only, through the purge unit, with water drained — The purge unit is not a charging point, and liquid first risks freezing.
  • Charge vapor only, through the compressor discharge, with pumps off — Centrifugals are charged through the evaporator charging valve, not the discharge.

This question on its own page

94. Low-pressure refrigerants such as R-123 are most often used in which type of equipment?
  • Household refrigerators
  • Residential split heat pumps
  • Supermarket display cases
  • Large centrifugal chillersCorrect answer

Why “Large centrifugal chillers” is correct

Low-pressure refrigerants have low vapor density and suit centrifugal compressors that move very large volumes of vapor. That is why the Type III exam centers on centrifugal chillers.

Source: EPA: Test Topics; 40 CFR 82.152

Why the other answers are wrong

  • Household refrigerators — Household refrigerators are small appliances, covered by Type I.
  • Residential split heat pumps — Residential splits use higher-pressure refrigerants such as R-410A.
  • Supermarket display cases — Display cases use medium- or high-pressure refrigerants.

This question on its own page

95. On an idle R-11 chiller, the refrigerant and water are both at 72 °F, but the gauge reads well above the pressure-temperature chart value for 72 °F. What is the likely cause?
  • A refrigerant undercharge
  • Too much oil in the sump
  • Chilled water flowing too fast
  • Air or other noncondensables in the chillerCorrect answer

Why “Air or other noncondensables in the chiller” is correct

With liquid and vapor present at a steady temperature, the pressure should match the P-T chart for that refrigerant. Extra pressure above that value comes from gases that do not condense, which the purge unit should remove.

Source: EPA: Test Topics

Why the other answers are wrong

  • A refrigerant undercharge — An undercharge does not raise standing pressure above the saturation value.
  • Too much oil in the sump — Oil level does not push pressure above the P-T value.
  • Chilled water flowing too fast — The chiller is idle, and water flow does not raise pressure above saturation.

This question on its own page

96. A closed R-123 chiller holds both liquid and vapor. If the refrigerant warms from 70 °F to 90 °F, what happens to its pressure?
  • It goes from below to above atmospheric pressureCorrect answer
  • It stays the same, since the chiller is closed
  • It falls further into a vacuum
  • It jumps to about 100 psig

Why “It goes from below to above atmospheric pressure” is correct

R-123 boils at about 82 °F at atmospheric pressure. Below that temperature its saturation pressure is a vacuum; above it, slightly positive. The same rule is why warming the refrigerant can bring a chiller above atmosphere for leak testing.

Source: EPA: Test Topics; Hudson Technologies R-123 and R-11 P-T charts

Why the other answers are wrong

  • It stays the same, since the chiller is closed — Saturated refrigerant pressure follows temperature even in a closed vessel.
  • It falls further into a vacuum — Warming raises saturation pressure; it does not lower it.
  • It jumps to about 100 psig — R-123 at 90 °F is only slightly above atmospheric pressure.

This question on its own page

97. Under ASHRAE Standard 34, which safety group is R-123 assigned to?
  • A1
  • A2L
  • B1Correct answer
  • B2L

Why “B1” is correct

R-123 is classed B1: "B" for higher toxicity and "1" for no flame propagation. Its higher toxicity is why EPA's test topics single out a refrigerant sensor for R-123 equipment rooms; current editions of ASHRAE Standard 15 require one for every refrigerant.

Source: ASHRAE Standard 34; Hudson Technologies R-123 P-T chart (ASHRAE 34 rating); EPA: Test Topics

Why the other answers are wrong

  • A1 — A1 is the lower-toxicity, non-flammable group of refrigerants such as R-11 and R-134a.
  • A2L — A2L is for lower-toxicity, mildly flammable refrigerants.
  • B2L — B2L is for higher-toxicity, mildly flammable refrigerants such as ammonia.

This question on its own page

98. The R-123 alarm is sounding in an equipment room after a major leak. What protection is needed to go in?
  • A paper dust mask
  • Safety glasses and gloves only
  • A self-contained breathing apparatusCorrect answer
  • A cartridge respirator for paint fumes

Why “A self-contained breathing apparatus” is correct

A large leak can leave the room short of oxygen and full of refrigerant vapor. In that extreme case only self-contained breathing apparatus supplies safe air; otherwise people should stay out until the room is ventilated.

Source: EPA: Test Topics; ASHRAE 15-2016 Addendum c, Appendix E

Why the other answers are wrong

  • A paper dust mask — Dust masks do not protect against refrigerant vapor or low oxygen.
  • Safety glasses and gloves only — Glasses and gloves do not protect breathing.
  • A cartridge respirator for paint fumes — Cartridge respirators do not supply oxygen in a displaced atmosphere.

This question on its own page

99. What is the job of the rupture disc on a low-pressure chiller?
  • Remove noncondensables from the condenser
  • Relieve excess pressure before the shell can burstCorrect answer
  • Let refrigerant out during normal operation
  • Act as the charging point for liquid

Why “Relieve excess pressure before the shell can burst” is correct

ASHRAE Standard 15 requires pressure relief on refrigerant vessels. On a low-pressure chiller this is usually a rupture disc, which bursts if pressure gets too high, protecting the shell but releasing refrigerant. That is why leak test pressures stay well below its setting.

Source: ASHRAE Standard 15; EPA: Test Topics

Why the other answers are wrong

  • Remove noncondensables from the condenser — Removing noncondensables is the purge unit's job.
  • Let refrigerant out during normal operation — A rupture disc only opens on dangerous overpressure.
  • Act as the charging point for liquid — The evaporator charging valve is the charging point.

This question on its own page

100. Under ASHRAE Standard 15, what should an equipment-room refrigerant detector do when it senses refrigerant above its set point?
  • Sound an alarm and start mechanical ventilationCorrect answer
  • Shut off all power to the building
  • Open the chiller rupture disc
  • Start the purge unit to remove the leak

Why “Sound an alarm and start mechanical ventilation” is correct

ASHRAE Standard 15 ties the equipment-room detector to visual and audible alarms and to mechanical ventilation, with a set point no higher than the refrigerant's occupational exposure limit. People are warned to leave, and fresh air is brought in to clear the leaked refrigerant.

Source: ASHRAE 15-2016 Addendum c (detector set point at OEL); EPA: Test Topics

Why the other answers are wrong

  • Shut off all power to the building — The detector does not cut building power.
  • Open the chiller rupture disc — Opening the disc would release the whole charge.
  • Start the purge unit to remove the leak — The purge removes noncondensables from inside the chiller, not refrigerant from the room.

This question on its own page

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.