22 Core Practice Questions & Answers

1. 1. What role does stratospheric ozone play that makes its depletion a concern addressed by Section 608?

   • A.It cools the lower atmosphere by reflecting heat
   • B.It traps oxygen at ground level for breathing
   • C.It generates the wind currents that drive weather
   • D.It absorbs harmful ultraviolet (UV) radiation from the sun✓ Answer

   The stratospheric ozone layer shields the Earth's surface by absorbing most of the sun's biologically damaging UV radiation, so depleting it increases UV exposure that harms humans, crops, and ecosystems.

   Source: Clean Air Act Title VI; EPA Section 608 Core, stratospheric ozone protection rationaleReport a problem with this question

2. 2. By what mechanism does chlorine released from a CFC molecule deplete ozone in the stratosphere?

   • A.Chlorine bonds permanently to one ozone molecule and stops
   • B.Chlorine freezes ozone so it falls to the ground
   • C.A single chlorine atom acts as a catalyst, destroying many ozone molecules without being used up✓ Answer
   • D.Chlorine adds oxygen atoms, thickening the ozone layer

   UV light frees a chlorine atom, which catalytically breaks ozone (O3) apart and is regenerated in the process, so one chlorine atom can destroy thousands of ozone molecules before it is finally removed.

   Source: EPA Section 608 Core, ozone-depletion chemistry (catalytic chlorine cycle)Report a problem with this question

3. 3. What is the primary purpose of the Montreal Protocol?

   • A.An international treaty to phase out the production of ozone-depleting substances✓ Answer
   • B.A standard defining refrigerant cylinder colors
   • C.A U.S. law setting minimum wages for HVAC technicians
   • D.A trade agreement lowering tariffs on air conditioners

   The Montreal Protocol is an international treaty, first agreed in 1987, under which nations committed to phasing out the production and consumption of ozone-depleting substances such as CFCs and HCFCs.

   Source: Montreal Protocol (1987); EPA Section 608 Core, international agreementsReport a problem with this question

4. 4. Which refrigerant class contains chlorine and therefore has the highest ozone-depletion potential?

   • A.HFOs (hydrofluoroolefins)
   • B.HFCs (hydrofluorocarbons)
   • C.CFCs (chlorofluorocarbons)✓ Answer
   • D.Ammonia (R-717)

   CFCs are fully halogenated and carry the most chlorine, giving them the highest ozone-depletion potential; HCFCs contain less chlorine (lower ODP) and HFCs contain no chlorine (zero ODP).

   Source: EPA Section 608 Core, refrigerant classes and ozone-depletion potentialReport a problem with this question

5. 5. Why do HFC refrigerants have an ozone-depletion potential (ODP) of essentially zero, even though they are still regulated?

   • A.They contain no chlorine, but they are regulated because they are potent greenhouse gases✓ Answer
   • B.They are natural refrigerants that pose no hazards
   • C.They break down before reaching the stratosphere, so they have no environmental effect
   • D.They contain extra chlorine that neutralizes ozone damage

   HFCs contain no chlorine, so they do not deplete stratospheric ozone; they remain regulated because many have a high global-warming potential (GWP) as greenhouse gases.

   Source: EPA Section 608 Core; refrigerant class ODP vs. GWP distinctionReport a problem with this question

6. 6. Under Section 608, what does 'recovery' of refrigerant mean?

   • A.Removing refrigerant from a system and storing it in an external container, in any condition✓ Answer
   • B.Reprocessing refrigerant to meet a certified purity standard
   • C.Cleaning refrigerant on site so it can be reused
   • D.Venting refrigerant slowly to reduce pressure spikes

   Recovery is defined as removing refrigerant in any condition from a system and storing it in an external container, without necessarily testing or processing it in any way.

   Source: 40 CFR 82.152 definition of 'recover'Report a problem with this question

7. 7. What distinguishes 'recycling' of refrigerant from 'reclaiming' it?

   • A.Recycling requires venting to the atmosphere first
   • B.Recycling always destroys the refrigerant
   • C.Recycling cleans refrigerant on site (e.g., oil separation, filtering) for reuse without meeting a certified purity spec✓ Answer
   • D.Recycling is done only at an off-site laboratory

   Recycling reduces contaminants through oil separation and single or multiple passes through filter-driers, and is typically done on site; reclaiming reprocesses refrigerant to a certified purity standard verified by chemical analysis.

   Source: 40 CFR 82.152 definitions of 'recycle' and 'reclaim'Report a problem with this question

8. 8. To what standard must refrigerant be reprocessed in order to be legally 'reclaimed'?

   • A.To half the moisture of the original charge
   • B.To the purity specified in AHRI Standard 700, verified by chemical analysis✓ Answer
   • C.To the color of a new refrigerant sample
   • D.To whatever purity the technician judges adequate by sight

   Reclaimed refrigerant must be reprocessed to at least the purity specified in AHRI (formerly ARI) Standard 700 and be chemically analyzed to verify it meets that specification; this is stricter than on-site recycling.

   Source: 40 CFR 82.152 'reclaim'; AHRI Standard 700 purity specificationReport a problem with this question

9. 9. What is the general rule regarding venting (knowingly releasing) refrigerant during service, maintenance, or disposal of appliances?

   • A.Venting is allowed as long as it is done outdoors
   • B.Venting is allowed whenever recovery equipment is unavailable
   • C.Venting is allowed if the amount is under one pound
   • D.Knowingly venting is prohibited; refrigerant must be recovered instead✓ Answer

   The Clean Air Act prohibits the knowing release (venting) of regulated refrigerants during service, maintenance, repair, and disposal; technicians must recover the refrigerant rather than release it.

   Source: Clean Air Act §608(c); 40 CFR 82.154 venting prohibitionReport a problem with this question

10. 10. Which of the following is an example of a permitted 'de minimis' release rather than illegal venting?

    • A.Emptying a full cylinder to make room for more refrigerant
    • B.Small amounts released while making or breaking connections in good-faith service after recovery✓ Answer
    • C.Blowing out a system with refrigerant to clear a blockage
    • D.Releasing the charge because a customer is in a hurry

    De minimis releases are the tiny, unavoidable amounts that escape during good-faith attempts to recover and recycle—such as when making or breaking service connections—and are not considered a violation of the venting prohibition.

    Source: 40 CFR 82.154; Clean Air Act §608 de minimis release provisionReport a problem with this question

11. 11. Which certification type covers 'small appliances,' such as household refrigerators, window air conditioners, and vending machines?

    • A.No certification is required for these
    • B.Type I✓ Answer
    • C.Type II
    • D.Type III

    Type I certification covers small appliances—products manufactured, charged, and hermetically sealed with five pounds or less of refrigerant, such as refrigerators, window units, and vending machines.

    Source: 40 CFR 82.161; EPA Section 608 Type I small-appliance definitionReport a problem with this question

12. 12. A technician who services residential central air conditioners and supermarket refrigeration racks that use high-pressure refrigerants needs which certification?

    • A.Type IV
    • B.Type I
    • C.Type II✓ Answer
    • D.Type III

    Type II certification is required to service or dispose of high-pressure and very-high-pressure appliances, which include residential and commercial air conditioning and most supermarket refrigeration.

    Source: 40 CFR 82.161; EPA Section 608 Type II high-pressure appliancesReport a problem with this question

13. 13. Type III certification is specifically required to service which category of equipment?

    • A.High-pressure automotive air conditioners
    • B.Portable window units only
    • C.Low-pressure appliances, such as chillers using refrigerants like R-11 or R-123✓ Answer
    • D.Small hermetically sealed appliances

    Type III certification covers low-pressure appliances—typically centrifugal chillers that use low-pressure refrigerants such as R-11, R-123, or R-113—which require special recovery procedures because they operate below atmospheric pressure.

    Source: 40 CFR 82.161; EPA Section 608 Type III low-pressure appliancesReport a problem with this question

14. 14. What does 'Universal' certification under Section 608 signify?

    • A.The technician has passed the Core exam plus Type I, II, and III✓ Answer
    • B.The technician can service any equipment worldwide without local rules
    • C.It is a temporary permit for apprentices
    • D.It replaces the need to pass the Core section

    A technician earns Universal certification by passing the Core section plus all three type-specific sections (I, II, and III), which qualifies them to service every category of stationary equipment covered by Section 608.

    Source: 40 CFR 82.161; EPA Section 608 Universal certificationReport a problem with this question

15. 15. Refrigerant recovery and recycling equipment manufactured for sale must meet what requirement?

    • A.It must be painted a specific color
    • B.It must be inspected annually by the fire department
    • C.It only needs the technician's personal approval
    • D.It must be certified by an EPA-approved testing organization to meet EPA standards✓ Answer

    Recovery and recycling equipment must be certified by an EPA-approved equipment-testing organization (such as UL or AHRI) as meeting EPA's performance standards, ensuring it recovers refrigerant to the required levels.

    Source: 40 CFR 82.158; EPA equipment certification requirementsReport a problem with this question

16. 16. Why must different refrigerants never be mixed together in the same recovery cylinder?

    • A.Mixed refrigerants become non-flammable
    • B.Mixing improves cooling performance
    • C.Mixed refrigerants cannot be reclaimed and usually must be destroyed, and mixing can create unsafe pressures✓ Answer
    • D.Mixing is required to fill a cylinder completely

    Mixed refrigerants cannot be separated or reclaimed to a usable purity, so they generally must be destroyed at added cost, and combining refrigerants with different pressures can create dangerous cylinder pressures.

    Source: EPA Section 608 Core, refrigerant handling and cross-contamination safetyReport a problem with this question

17. 17. To prevent dangerous overpressure, a refrigerant recovery cylinder should never be filled beyond what fraction of its capacity?

    • A.100% (completely full is safest)
    • B.95% (only vapor space matters)
    • C.50% (half is the legal maximum)
    • D.80% (to leave room for liquid expansion)✓ Answer

    Recovery cylinders must not be filled above 80% of capacity so that liquid refrigerant has room to expand as temperature rises; a fully liquid-filled cylinder can rupture from hydrostatic pressure.

    Source: DOT/EPA Section 608 Core, cylinder filling and pressure safety (80% rule)Report a problem with this question

18. 18. What color scheme identifies a DOT-approved refrigerant recovery cylinder?

    • A.Solid red overall
    • B.A blue body with a white top
    • C.A gray body with a yellow top (shoulder)✓ Answer
    • D.Solid green overall

    Recovery cylinders are identified by a gray body with a yellow top; this standardized coloring signals that the cylinder holds recovered (potentially mixed or contaminated) refrigerant, distinct from color-coded virgin refrigerant containers.

    Source: DOT cylinder marking; EPA Section 608 Core, recovery cylinder identificationReport a problem with this question

19. 19. Which personal protective equipment is most important when there is a risk of liquid refrigerant contacting the skin or eyes?

    • A.A high-visibility vest
    • B.Hearing protection
    • C.Safety glasses/goggles and protective gloves✓ Answer
    • D.A hard hat and steel-toe boots only

    Liquid refrigerant can flash-evaporate on contact and cause frostbite or severe eye injury, so gloves and eye protection are essential when there is any chance of liquid contact.

    Source: EPA Section 608 Core, technician safety and PPE for refrigerant contactReport a problem with this question

20. 20. What two hazards make working with refrigerants in a confined or poorly ventilated space especially dangerous?

    • A.Oxygen displacement/asphyxiation, and toxic decomposition products if refrigerant contacts a flame or hot surface✓ Answer
    • B.Slippery floors and bright glare
    • C.Increased humidity and mild eye irritation only
    • D.Static electricity and loud noise

    Most refrigerants are heavier than air and displace oxygen in low or confined spaces, risking asphyxiation, and when exposed to open flame or high heat they decompose into toxic products such as phosgene and acidic gases.

    Source: EPA Section 608 Core, refrigerant safety hazards (asphyxiation and thermal decomposition)Report a problem with this question

21. 21. A halide torch leak detector produces a color change in its flame only in the presence of which kind of refrigerant?

    • A.Any refrigerant, including chlorine-free HFCs
    • B.Chlorine-containing refrigerants (such as CFCs and HCFCs)✓ Answer
    • C.Only carbon dioxide
    • D.Only ammonia

    A halide torch changes flame color (green/blue) when the refrigerant contains chlorine, so it detects CFCs and HCFCs but will not respond to chlorine-free HFCs; electronic detectors or soap bubbles are used for those.

    Source: EPA Section 608 Core, leak-detection methods (halide torch chlorine sensitivity)Report a problem with this question

22. 22. In the basic refrigeration cycle, which component absorbs heat from the space being cooled as low-pressure refrigerant boils into a vapor?

    • A.The compressor
    • B.The metering (expansion) device
    • C.The condenser (on the high-pressure side)
    • D.The evaporator (on the low-pressure side)✓ Answer

    The evaporator is on the low-pressure side; low-pressure liquid refrigerant boils there, absorbing heat from the surroundings, while the condenser on the high-pressure side rejects that heat as the vapor condenses back to liquid.

    Source: EPA Section 608 Core, basic refrigeration cycle (evaporator/condenser roles, high vs. low side)Report a problem with this question

Practice questions modeled on the EPA Section 608 Technician Certification content (Clean Air Act §608; 40 CFR Part 82). Not affiliated with or endorsed by the U.S. Environmental Protection Agency or any approved certifying organization. Study the official EPA program materials before testing. Official EPA 608 →