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Free EPA 608 Practice Test

24 practice questions across Core, Type I, Type II and Type III. Answer them all, then see your score for each section with an explanation for every question.

These 24 practice questions were written by Skill Ready Techs to help you study. They are not official EPA exam questions, and a score here is not a certification. Regulations change, so check the EPA’s current Section 608 requirements before your test.

Core

Rules and science every Section 608 technician is expected to know.

1. What does the stratospheric ozone layer do? Produces the oxygen we breathe Shields the earth from harmful ultraviolet (UV-B) radiation Filters dust and smoke out of the air Traps heat to keep the planet warm

Why: Chlorine from CFC and HCFC refrigerants destroys ozone, letting more UV-B reach the surface.

2. Which of these refrigerants has the highest ozone depletion potential? R-12 (a CFC) R-22 (an HCFC) R-410A (an HFC blend) R-134a (an HFC)

Why: CFCs carry the most chlorine and are the most damaging to ozone. HCFCs are lower, and HFCs have none.

3. HFC refrigerants such as R-134a and R-410A: Deplete ozone more than CFCs do Contain no chlorine and do not deplete ozone, but are greenhouse gases Are classified as highly flammable (A3) Are not regulated and may be vented

Why: HFCs have zero ozone depletion potential but high global warming potential, and it is illegal to knowingly vent them.

4. Which international agreement began the phase-out of ozone-depleting refrigerants? The Clean Water Act The Kyoto Protocol The Montreal Protocol The Paris Agreement

Why: The Montreal Protocol, signed in 1987, set the schedule for phasing out CFCs and later HCFCs.

5. Section 608 technician certification comes from which federal law? The Energy Policy Act The Occupational Safety and Health Act The Clean Air Act The Resource Conservation and Recovery Act

Why: Section 608 is part of the Clean Air Act, which the EPA enforces.

6. Before refrigerant is transferred into an empty recovery cylinder, the cylinder should be: Evacuated, to remove air and moisture Warmed to at least 125°F Filled with nitrogen to 50 psig Stored upside down for an hour

Why: Air and moisture left in the cylinder contaminate the recovered refrigerant and raise its pressure.

Type I: small appliances

Factory-sealed appliances holding 5 pounds or less, such as refrigerators and window units.

7. Using recovery equipment made after November 15, 1993, how much of the charge must be recovered from a small appliance whose compressor still runs? 90 percent 100 percent 70 percent 80 percent

Why: With a working compressor: 90 percent, or a 4-inch mercury vacuum.

8. Using the same equipment, how much must be recovered when the small appliance’s compressor does not run? 99 percent 90 percent 80 percent 50 percent

Why: With a non-working compressor: 80 percent, or a 4-inch mercury vacuum.

9. A system-dependent (passive) recovery process: Releases the refrigerant through a filter into the air Uses a recovery machine with its own compressor Uses the appliance’s own compressor or internal pressure to move refrigerant into the recovery container Pushes the refrigerant out with compressed air

Why: Self-contained (active) recovery uses its own compressor. Passive recovery relies on the appliance.

10. A piercing-type access valve installed to recover from a sealed small appliance should be: Removed when the work is done, because these valves tend to leak Left in place permanently for future service Brazed over while the system is under pressure Covered with tape

Why: Solderless piercing valves are for temporary access and are a known leak point if left on.

11. During recovery from a small appliance with a compressor that does not run, what helps release refrigerant trapped in the compressor oil? Warming the compressor and tapping it with a rubber mallet Adding more oil Packing the compressor in ice Disconnecting the recovery hoses

Why: Heat and vibration drive dissolved refrigerant out of the oil so it can be recovered.

12. You notice a strong, sharp odor while recovering refrigerant from a small appliance. What has most likely happened? The compressor has burned out The door gasket is leaking The filter drier is new The appliance is overcharged

Why: A burnout leaves acid and contaminants in the system. Protect yourself and your recovery equipment.

Type II: high-pressure appliances

Residential and commercial air conditioning, heat pumps and most refrigeration.

13. For a comfort cooling appliance holding 50 pounds or more of refrigerant, what annual leak rate triggers the repair requirement? 50 percent 30 percent 10 percent 20 percent

Why: Comfort cooling: 10 percent. Commercial refrigeration: 20 percent. Industrial process refrigeration: 30 percent.

14. For commercial refrigeration holding 50 pounds or more of refrigerant, what annual leak rate triggers the repair requirement? 35 percent 20 percent 10 percent 5 percent

Why: Commercial refrigeration, such as supermarket systems, has a 20 percent threshold.

15. When recovering from a high-pressure appliance that holds less than 200 pounds, with equipment made after November 15, 1993, the system must be evacuated to: 25 mm of mercury absolute 10 inches of mercury vacuum 0 inches of mercury vacuum 15 inches of mercury vacuum

Why: Under 200 pounds: 0 inches Hg. At 200 pounds or more: 10 inches Hg.

16. To shorten recovery time on a large system, a technician should begin by recovering: Vapor refrigerant The oil Liquid refrigerant Non-condensables

Why: Liquid moves far more refrigerant per minute. Recover liquid first, then the remaining vapor.

17. Recovery slows down as pressure in the recovery cylinder rises. What helps? Cooling the recovery cylinder Heating the recovery cylinder Laying the cylinder on its side Opening the cylinder’s relief valve

Why: A cooler cylinder has lower pressure, so refrigerant flows into it more easily.

18. When an appliance with 50 pounds or more of refrigerant exceeds its leak rate threshold, the leak generally must be repaired within: 1 year 30 days 24 hours 6 months

Why: Owners must repair within 30 days, then verify the repair held. Longer is allowed only in limited cases.

Type III: low-pressure appliances

Low-pressure chillers that run below atmospheric pressure.

19. Because the evaporator of a low-pressure chiller runs below atmospheric pressure, a leak usually: Has no effect until the system is shut down Sprays liquid refrigerant out Raises the oil level Draws air and moisture into the system

Why: Air and moisture leak in, which raises head pressure and causes corrosion.

20. What does the purge unit on a low-pressure chiller do? Adds refrigerant when the charge is low Removes air and other non-condensables from the system Cools the condenser water Circulates oil to the bearings

Why: Non-condensables collect at the top of the condenser, and the purge unit removes them.

21. What evacuation level is required when recovering refrigerant from a low-pressure appliance? 0 inches of mercury vacuum 25 mm of mercury absolute 500 microns 10 inches of mercury vacuum

Why: Low-pressure appliances must be pulled to 25 mm Hg absolute.

22. The rupture disc on a low-pressure chiller is typically set to relieve at: 15 psig 150 psig 5 psig 50 psig

Why: Low-pressure vessels are protected by a rupture disc set at about 15 psig.

23. When raising the pressure in a low-pressure chiller to check for leaks, do not exceed: 150 psig 10 psig 30 psig 75 psig

Why: Going higher risks blowing the 15 psig rupture disc. Controlled hot water or nitrogen is used to raise pressure.

24. How should refrigerant be added to a low-pressure chiller that is in a deep vacuum? As liquid first, as fast as possible As vapor first, until the pressure is above the point where water could freeze, then as liquid Through the purge unit With the chilled water pumps off and the tubes drained of air

Why: Liquid entering a deep vacuum can flash cold enough to freeze water in the tubes. Charge vapor until the saturation temperature is above 32°F.

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