EPA 608 Type I mock exam
Core plus Type I, 50 questions: the test you take for Type I certification.
Before you start
- 50 questions: 25 Core and 25 Type 1.
- Each section is scored on its own. On the real exam you need 70% in a section to pass it, and the results page shows your score against that mark.
- None of these questions appear on the practice pages, so this is a fair check of what you know.
- One question per page, with the answer and explanation shown as you go. No timer and no sign-up; your answers are saved in this browser so you can stop and come back.
What this test covers
- Core: Ozone depletion, the Clean Air Act, Section 608 rules, the three Rs, recovery basics, safety and shipping. Every 608 test includes 25 Core questions. Practice Core questions.
- Type I: Small appliances: factory-sealed with 5 pounds of refrigerant or less, like refrigerators, window units and dehumidifiers. Practice Type 1 questions.
Answer key: every answer, explained
Take the test first: the answers are here for checking afterwards. Each one says why it is right, why each other choice is wrong, and which rule it comes from.
Core
1. An older centrifugal chiller is charged with R-11. What type of refrigerant is R-11?
- HFC
- HCFC
- HFO
- CFCCorrect answer
Why “CFC” is correct
R-11 is a chlorofluorocarbon, and it is the reference refrigerant for ozone depletion potential with an ODP of 1.0. Its replacement in many chillers, R-123, is an HCFC.
Source: EPA: Test Topics
Why the other answers are wrong
- HFC — HFCs contain no chlorine; R-11 does.
- HCFC — R-123, not R-11, is the HCFC used in many newer low-pressure chillers.
- HFO — HFOs are recent low-GWP refrigerants, not R-11.
2. R-123 replaced R-11 in many low-pressure chillers. How is R-123 classified?
- HCFCCorrect answer
- CFC
- HFC
- Hydrocarbon
Why “HCFC” is correct
R-123 is a hydrochlorofluorocarbon. It contains chlorine and so still depletes ozone, but far less than the CFC R-11 it replaced. Like other HCFCs, it is being phased out.
Source: EPA: Test Topics
Why the other answers are wrong
- CFC — R-11 is the CFC; R-123 contains hydrogen as well.
- HFC — R-123 contains chlorine, so it is not an HFC.
- Hydrocarbon — R-123 contains chlorine and fluorine, so it is not a hydrocarbon.
3. What range of ozone depletion potential do HCFC refrigerants fall in, compared with CFC-11 at 1.0?
- About 0.01 to 0.1Correct answer
- About 0.6 to 1.0
- About 1.0 to 10
- Exactly zero
Why “About 0.01 to 0.1” is correct
HCFCs have ODPs of roughly 0.01 to 0.1. They still contain chlorine, but much of each molecule breaks down in the lower atmosphere before it reaches the stratosphere. The highest-ODP HCFCs were phased out first.
Source: EPA: Test Topics
Why the other answers are wrong
- About 0.6 to 1.0 — 0.6 to 1.0 is the range of the common CFCs.
- About 1.0 to 10 — ODPs up to 10 belong to the halons, not HCFCs.
- Exactly zero — An ODP of zero belongs to HFCs, which contain no chlorine.
4. Which part of the Clean Air Act directs EPA to protect the stratospheric ozone layer, including rules on recycling refrigerants?
- Title I
- Title IV
- Title VICorrect answer
- Title IX
Why “Title VI” is correct
Title VI of the Clean Air Act, added in the 1990 amendments, directs EPA to protect stratospheric ozone. It covers production of ozone-depleting substances, the recycling and handling of refrigerants, and the evaluation of substitutes. Section 608 is part of Title VI.
Source: EPA: Test Topics
Why the other answers are wrong
- Title I — Title I deals with ground-level air quality standards.
- Title IV — Title IV deals with acid rain.
- Title IX — There is no Title IX ozone program in the Clean Air Act.
5. A building owner who is not a technician opens a valve and releases R-410A from his own rooftop unit. Does the venting prohibition apply to him?
- No, it applies only to certified technicians
- Yes, it applies to anyone servicing or disposing of oneCorrect answer
- No, owners may do what they want with their own equipment
- Yes, but only if the unit holds more than 50 pounds
Why “Yes, it applies to anyone servicing or disposing of one” is correct
40 CFR 82.154(a)(1) says no person maintaining, servicing, repairing or disposing of an appliance may knowingly vent refrigerant. "Person" includes individuals and companies, so the rule applies to owners as well as technicians.
Source: 40 CFR 82.154(a)(1); 40 CFR 82.152
Why the other answers are wrong
- No, it applies only to certified technicians — The prohibition covers every person, not just certified technicians.
- No, owners may do what they want with their own equipment — Owning the equipment does not give permission to vent.
- Yes, but only if the unit holds more than 50 pounds — The venting prohibition has no charge-size threshold.
6. Under 40 CFR 82.152, which of these is not considered "opening an appliance"?
- Removing a compressor for replacement
- Connecting hoses and gauges to measure pressureCorrect answer
- Cutting a refrigerant line to replace a drier
- Unbrazing a condenser coil
Why “Connecting hoses and gauges to measure pressure” is correct
The definition of opening an appliance covers service that would release refrigerant to the atmosphere. Connecting and disconnecting hoses and gauges to measure pressures, add refrigerant or recover refrigerant is specifically not "opening," though it still requires certification.
Source: 40 CFR 82.152
Why the other answers are wrong
- Removing a compressor for replacement — Removing a compressor exposes the refrigerant circuit and is opening the appliance.
- Cutting a refrigerant line to replace a drier — Cutting a line opens the refrigerant circuit.
- Unbrazing a condenser coil — Unbrazing a coil opens the refrigerant circuit.
7. Under 40 CFR 82.154(e), a new small appliance sold in the U.S. must come with what feature to make recovery possible?
- A pressure relief valve
- A sight glass
- A permanently attached recovery unit
- A process stubCorrect answer
Why “A process stub” is correct
New small appliances must have a process stub, a length of tubing that gives access to the refrigerant and can be resealed. Larger appliances must have a servicing aperture. Both make recovery at service and disposal possible.
Source: 40 CFR 82.154(e); 40 CFR 82.152
Why the other answers are wrong
- A pressure relief valve — Relief valves protect against overpressure but are not the required access point.
- A sight glass — A sight glass shows liquid flow and is not required for recovery.
- A permanently attached recovery unit — Permanently attached recovery units are not required.
8. A refrigerant wholesaler sells R-454B to a contractor. Which records must the wholesaler keep, and for how long?
- The address of the appliance being serviced, for five years
- The technician's test score, for one year
- Invoices with buyer, date and quantity, for three yearsCorrect answer
- No records, because R-454B is a substitute
Why “Invoices with buyer, date and quantity, for three years” is correct
Under 40 CFR 82.154(c)(3), sellers of class I, class II and non-exempt substitute refrigerants must keep invoices showing the purchaser's name, the date of sale and the quantity sold, plus any proof of a certified employee, for three years.
Source: 40 CFR 82.154(c)(3)
Why the other answers are wrong
- The address of the appliance being serviced, for five years — The wholesaler does not have to record where the refrigerant will be used.
- The technician's test score, for one year — Test scores are kept by certifying programs, not wholesalers.
- No records, because R-454B is a substitute — Non-exempt substitutes have been covered by the sales restriction since January 1, 2018.
9. After taking the Section 608 test, how soon must the certifying program send the results?
- Within 7 days
- Within 30 daysCorrect answer
- Within 90 days
- Within one year
Why “Within 30 days” is correct
Appendix D requires certifying programs to give applicants their results no later than 30 days from the test date and to issue the wallet card within 30 days. For mail-in Type I tests the 30 days run from when the program receives the completed test.
Source: 40 CFR Part 82, Subpart F, Appendix D; EPA: Section 608 Q&A
Why the other answers are wrong
- Within 7 days — Seven days is not the deadline in the rule.
- Within 90 days — Ninety days is longer than the rule allows.
- Within one year — One year is far longer than the 30-day deadline.
10. A technician wants to service small appliances, high-pressure systems and low-pressure chillers. Which certification covers all of them?
- Type II
- Type III
- UniversalCorrect answer
- Core only
Why “Universal” is correct
Universal certification covers everything that Types I, II and III cover. It requires passing Core and all three type sections under closed-book, proctored conditions, either in one sitting or by combining separate passing scores.
Source: 40 CFR 82.161(a)(1); 40 CFR Part 82, Subpart F, Appendix D
Why the other answers are wrong
- Type II — Type II does not cover small appliances or low-pressure chillers.
- Type III — Type III covers only low-pressure appliances.
- Core only — Core alone does not certify a technician for any equipment.
11. A technician plans to convert an R-22 system to a substitute refrigerant. What must be done with the R-22 first?
- Recover it with certified recovery equipmentCorrect answer
- Vent it, since R-22 is being phased out
- Leave it in and add the substitute on top
- Mix it with the substitute in a cylinder
Why “Recover it with certified recovery equipment” is correct
The existing charge must be recovered before the system is opened for a retrofit. The new refrigerant's lubricant and component requirements are then followed, because a retrofit is not a simple drop-in.
Source: 40 CFR 82.154(a); 40 CFR 82.152
Why the other answers are wrong
- Vent it, since R-22 is being phased out — Venting R-22 is a violation, phaseout or not.
- Leave it in and add the substitute on top — Adding a substitute on top creates a mixture of unknown composition.
- Mix it with the substitute in a cylinder — Mixing refrigerants makes them hard or impossible to reclaim.
12. Which lubricant was traditionally used in R-12 CFC refrigeration systems?
- Silicone oil
- Polyolester oil
- Polyalkylene glycol oil
- Mineral oilCorrect answer
Why “Mineral oil” is correct
CFC systems such as those using R-12 traditionally used mineral oil. Many substitute refrigerants, including HFCs, do not mix with mineral oil, which is why retrofits often require an oil change.
Source: EPA: Test Topics
Why the other answers are wrong
- Silicone oil — Silicone oil is not used as a refrigeration compressor lubricant.
- Polyolester oil — Polyolester oil is the usual partner for HFCs such as R-134a.
- Polyalkylene glycol oil — PAG oil is used mainly in automotive R-134a systems.
13. In a running system, what is in the liquid line between the condenser and the metering device?
- High-pressure liquidCorrect answer
- Low-pressure vapor
- High-pressure vapor
- Low-pressure liquid and vapor
Why “High-pressure liquid” is correct
After the condenser removes heat, the refrigerant is a high-pressure liquid, usually slightly subcooled. It flows through the liquid line to the metering device, where its pressure drops.
Source: EPA: Test Topics
Why the other answers are wrong
- Low-pressure vapor — Low-pressure vapor is in the suction line.
- High-pressure vapor — High-pressure vapor is in the discharge line before the condenser.
- Low-pressure liquid and vapor — A low-pressure mix is found after the metering device, in the evaporator.
14. When a single-component refrigerant is boiling in the evaporator at a steady pressure, what happens to its temperature?
- It rises steadily as it boils
- It stays about the same while liquid remainsCorrect answer
- It falls steadily as it boils
- It swings up and down with each compressor stroke
Why “It stays about the same while liquid remains” is correct
While a pure refrigerant changes from liquid to vapor at a fixed pressure, it stays at its saturation temperature; the heat it absorbs goes into boiling, not into raising temperature. Only after all liquid has boiled does the vapor begin to warm (superheat).
Source: EPA: Test Topics
Why the other answers are wrong
- It rises steadily as it boils — Temperature rises only after all the liquid has boiled off.
- It falls steadily as it boils — At constant pressure the boiling temperature does not fall.
- It swings up and down with each compressor stroke — Saturation temperature follows pressure, not compressor strokes.
15. Why do technicians use low-loss fittings on their hoses?
- To filter moisture out of the refrigerant as it flows
- To make hoses connect faster
- To cut refrigerant loss when hoses are disconnectedCorrect answer
- To raise the pressure rating of the hose
Why “To cut refrigerant loss when hoses are disconnected” is correct
40 CFR 82.152 defines a low-loss fitting as one that closes automatically or manually when disconnected, minimizing refrigerant released from hoses, appliances and recovery machines. It keeps the trapped hose charge from escaping.
Source: 40 CFR 82.152
Why the other answers are wrong
- To filter moisture out of the refrigerant as it flows — Fittings do not filter moisture; filter-driers do.
- To make hoses connect faster — Speed of connection is not the purpose.
- To raise the pressure rating of the hose — The fitting does not change the hose pressure rating.
16. A compressor burnout has left the R-22 in a system acidic and dirty. What must the technician do with it?
- Vent it, since it cannot be reused
- Mix it with clean R-22 to dilute it
- Leave it in the system
- Recover it into a recovery cylinderCorrect answer
Why “Recover it into a recovery cylinder” is correct
Recovery means removing refrigerant in any condition and storing it in an external container. Contaminated refrigerant must still be recovered; it can then be recycled for the same owner, sent for reclamation, or destroyed.
Source: 40 CFR 82.152; 40 CFR 82.154(a)
Why the other answers are wrong
- Vent it, since it cannot be reused — Contamination is not a reason to vent.
- Mix it with clean R-22 to dilute it — Diluting with clean refrigerant spreads the contamination.
- Leave it in the system — The system cannot be opened for repair with the refrigerant left in it.
17. In a recycling machine, what do the replaceable core filter-driers reduce?
- The amount of refrigerant in the cylinder
- Chlorine content of the refrigerant
- The refrigerant's ozone depletion potential
- Moisture, acidity and particlesCorrect answer
Why “Moisture, acidity and particles” is correct
40 CFR 82.152 notes that recycled refrigerant is generally cleaned by oil separation and passes through devices such as replaceable core filter-driers, which reduce moisture, acidity and particulate matter.
Source: 40 CFR 82.152
Why the other answers are wrong
- The amount of refrigerant in the cylinder — Filter-driers clean refrigerant; they are not meant to reduce the amount.
- Chlorine content of the refrigerant — Chlorine is part of the refrigerant molecule and is not filtered out.
- The refrigerant's ozone depletion potential — ODP is a property of the chemical and does not change.
18. Why should a new recovery cylinder be evacuated before its first use?
- To check that the cylinder is the correct color and type
- To remove air that would mix with the refrigerantCorrect answer
- To pre-cool the cylinder walls
- To meet the 80 percent fill limit
Why “To remove air that would mix with the refrigerant” is correct
A cylinder full of air would add non-condensables to the recovered refrigerant and raise cylinder pressure. Evacuating it first leaves a clean, empty container.
Source: EPA: Test Topics
Why the other answers are wrong
- To check that the cylinder is the correct color and type — Evacuation has nothing to do with cylinder color.
- To pre-cool the cylinder walls — Pulling a vacuum does not meaningfully cool the cylinder.
- To meet the 80 percent fill limit — The fill limit is met by weighing, not by evacuation.
19. Before recovering from an unfamiliar system, why should the technician confirm which refrigerant it holds?
- To pick the right cylinder and avoid mixingCorrect answer
- To decide whether the refrigerant may be vented
- To set the thermostat correctly
- To find the date the system was made
Why “To pick the right cylinder and avoid mixing” is correct
Each refrigerant should go into its own cylinder, so knowing the refrigerant first keeps it from being mixed with another. Check the nameplate and the system pressures before connecting.
Source: EPA: Test Topics
Why the other answers are wrong
- To decide whether the refrigerant may be vented — Non-exempt refrigerants may never be vented.
- To set the thermostat correctly — The thermostat setting has nothing to do with recovery.
- To find the date the system was made — The manufacture date is on the nameplate, but that is not the reason for identifying the refrigerant.
20. After evacuation the vacuum pump is valved off. The micron reading rises, then levels off and holds. What does this most likely mean?
- The vacuum is deep enough to charge
- The system has a large leak to the atmosphere
- Moisture is still boiling off inside the systemCorrect answer
- The micron gauge has failed
Why “Moisture is still boiling off inside the system” is correct
A reading that rises and then levels off usually means moisture or refrigerant is still turning to vapor inside a tight system. A reading that keeps rising without leveling off suggests a leak. More evacuation is needed before charging.
Source: EPA: Test Topics
Why the other answers are wrong
- The vacuum is deep enough to charge — A significant rise shows the system is not yet dry.
- The system has a large leak to the atmosphere — A leak to the atmosphere keeps the reading rising instead of leveling off.
- The micron gauge has failed — A gauge that responds this way is working.
21. Why must a refrigerant cylinder never be heated with a torch?
- The pressure can rise rapidly and rupture the cylinderCorrect answer
- The flame will turn the refrigerant into oxygen
- It voids the cylinder's color code
- It makes the refrigerant flammable
Why “The pressure can rise rapidly and rupture the cylinder” is correct
Heating a cylinder with an open flame can raise its pressure and weaken the metal, causing a rupture or explosion. Open flames can also break refrigerant down into toxic products.
Source: EPA: Test Topics
Why the other answers are wrong
- The flame will turn the refrigerant into oxygen — Heat does not turn refrigerant into oxygen.
- It voids the cylinder's color code — The danger is rupture, not the color code.
- It makes the refrigerant flammable — Heating does not make a nonflammable refrigerant flammable; the hazard is pressure.
22. How can a technician make sure a recovery cylinder stays under the 80 percent fill limit?
- Stop as soon as the recovery machine sounds strained
- Watch the cylinder pressure gauge
- Feel the side of the cylinder for cold spots
- Weigh it and compare with its allowed fill weightCorrect answer
Why “Weigh it and compare with its allowed fill weight” is correct
Pressure in a cylinder depends on temperature, not on how full it is, so a gauge cannot show the fill level. Weighing the cylinder, or using a float switch on cylinders that have one, shows how much liquid is inside.
Source: EPA: Test Topics
Why the other answers are wrong
- Stop as soon as the recovery machine sounds strained — Machine sound does not measure fill level.
- Watch the cylinder pressure gauge — Cylinder pressure follows temperature, not the amount of liquid.
- Feel the side of the cylinder for cold spots — Cold spots are an unreliable guess at the liquid level.
23. A technician will pressure-test a system with nitrogen. What limit should the test pressure respect?
- The full pressure available from the nitrogen cylinder
- The rated test pressure for that systemCorrect answer
- Whatever pressure the relief valve allows
- At least twice the system's normal operating pressure
Why “The rated test pressure for that system” is correct
The test pressure must not exceed what the system and its components are built for, as shown on the nameplate or in the manufacturer's instructions. A regulator sets that pressure, and a relief valve protects against regulator failure.
Source: EPA: Test Topics
Why the other answers are wrong
- The full pressure available from the nitrogen cylinder — Full cylinder pressure can be thousands of psig and would burst the system.
- Whatever pressure the relief valve allows — The relief valve is a backup, not the target pressure.
- At least twice the system's normal operating pressure — Doubling operating pressure can exceed the system rating.
24. A refrigerant leak has made the air in a small mechanical room stuffy and you feel dizzy. What should you do first?
- Light a torch to burn off the refrigerant
- Keep working quickly to finish the repair
- Leave the area and ventilate itCorrect answer
- Lie down on the floor until it passes
Why “Leave the area and ventilate it” is correct
Dizziness is a warning of oxygen deprivation or refrigerant overexposure. Get to fresh air, ventilate the space, and return only when it is safe or with proper breathing equipment.
Source: EPA: Test Topics
Why the other answers are wrong
- Light a torch to burn off the refrigerant — An open flame can break refrigerant down into toxic gases.
- Keep working quickly to finish the repair — Staying in the space can lead to unconsciousness or heart effects.
- Lie down on the floor until it passes — Refrigerant vapor collects low, so lying on the floor is the worst place to be.
25. What does the DOT classification tag on a refrigerant cylinder tell carriers and handlers?
- The technician who filled the cylinder
- The date the refrigerant was made
- The hazard class of the contentsCorrect answer
- The price per pound
Why “The hazard class of the contents” is correct
The Department of Transportation classification tag shows the hazard class of the cylinder's contents, such as nonflammable gas, so carriers handle it correctly. It goes alongside a label identifying the refrigerant itself.
Source: EPA: Test Topics
Why the other answers are wrong
- The technician who filled the cylinder — The tag does not identify who filled the cylinder.
- The date the refrigerant was made — Manufacture date is not what the DOT tag shows.
- The price per pound — Pricing is not part of hazard labeling.
Type 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.