Answer 10 free questions

EPA 608 Certification: 10 free questions

Tap an answer to see if you're right and why, or switch to Timed and get scored at the end. Each answer is also under its question.

1. EPA 608 Core

   Which atom in a refrigerant molecule is responsible for destroying ozone in the stratosphere?

   AChlorine BHydrogen CCarbon DFluorine
   Show answer

   Answer: A. Chlorine

   Chlorine released from CFC and HCFC molecules attacks ozone. Fluorine, hydrogen and carbon do not break ozone down this way. Source: general refrigeration practice.

   • B: Hydrogen does not attack ozone; it helps HCFCs break down sooner
   • C: Carbon is the backbone of the molecule, not the ozone destroyer
   • D: Fluorine stays tightly bound and is not the ozone destroyer
2. EPA 608 Type I (Small Appliances)

   Under EPA's Section 608 rules, a small appliance is one that is fully manufactured, charged, and hermetically sealed in a factory with how much refrigerant?

   A10 pounds or less B5 pounds or less CLess than 50 pounds D15 pounds or less
   Show answer

   Answer: B. 5 pounds or less

   EPA defines a small appliance by its factory-sealed charge: five pounds of refrigerant or less. Anything with a bigger charge is not a small appliance. Source: 40 CFR 82.152 (definition of small appliance).

   • A: The limit is 5 pounds, not 10.
   • C: Fifty pounds is not a limit in the definition; the limit is 5 pounds.
   • D: The limit is 5 pounds, not 15.
3. EPA 608 Type II (High-Pressure)

   A high-pressure chiller or air-conditioning system shows a higher-than-normal suction superheat and a low charge indication. What is the most likely cause?

   ANon-condensables are trapped in the condenser BThe oil charge is too high CThe condenser is overcharged with liquid DRefrigerant has leaked out and the system is undercharged
   Show answer

   Answer: D. Refrigerant has leaked out and the system is undercharged

   A leak lowers the charge, so the evaporator is starved of liquid and the vapor leaving it picks up excess superheat. Excessive superheat is one of the classic signs of a refrigerant leak in a high-pressure system. Source: general refrigeration practice.

   • A: Non-condensables raise head pressure but do not starve the evaporator.
   • B: Extra oil does not starve the evaporator of refrigerant.
   • C: An overcharge raises head pressure and lowers superheat rather than raising it.
4. EPA 608 Type III (Low-Pressure)

   A technician needs to raise the pressure in a low-pressure centrifugal chiller to look for a leak. Which pressurization method is preferred first?

   ACompressed shop air BControlled hot water or a built-in heating device CNitrogen from a cylinder through a regulator valve DPure oxygen from a welding cylinder and regulator
   Show answer

   Answer: B. Controlled hot water or a built-in heating device

   Low-pressure chillers are normally pressurized with heat first: controlled warm water circulated through the tubes, or a built-in system heating/pressurization device such as a Prevac. Heat raises the refrigerant's own vapor pressure without adding anything to the system. Nitrogen is the fallback after heat has done what it can. Source: 40 CFR 82.156(a)(1)(ii).

   • A: Shop air adds moisture and oxygen to the system and is never an acceptable test gas.
   • C: Nitrogen is the second choice, used only after heat has raised the pressure as far as it can.
   • D: Oxygen with refrigerant oil is an explosion hazard and is never used.
5. EPA 608 Core

   Which international treaty set the schedule for phasing out production of ozone-depleting substances such as CFCs?

   AThe Kyoto Protocol BThe Geneva Convention CThe Montreal Protocol DThe Paris Agreement
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   Answer: C. The Montreal Protocol

   The Montreal Protocol on Substances That Deplete the Ozone Layer is the international agreement controlling the phaseout of ozone-depleting substances. In the US the Clean Air Act, as amended in 1990, carries it out. Source: general refrigeration practice.

   • A: The Kyoto Protocol addressed greenhouse gas emissions, not ozone-depleting substances.
   • B: The Geneva Convention covers the conduct of war.
   • D: The Paris Agreement addresses climate change, not ozone depletion.
6. EPA 608 Type I (Small Appliances)

   A recovery cylinder has sat in a shop at a steady temperature for several hours. Its pressure is noticeably higher than the pressure-temperature chart shows for the refrigerant at that temperature. What is the most likely cause?

   AThe cylinder valve is a different thread size BThe cylinder is filled with too little liquid CThe refrigerant has become more dense DNoncondensable gas such as air in the cylinder
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   Answer: D. Noncondensable gas such as air in the cylinder

   Air does not condense at cylinder pressures, so it adds its own pressure on top of the refrigerant's saturation pressure. A cylinder holding only the labeled refrigerant, with liquid and vapor at a steady temperature, reads on the chart. Source: general refrigeration practice.

   • A: Valve thread size has no effect on pressure.
   • B: Fill level does not change saturation pressure while liquid and vapor are both present.
   • C: Density does not raise saturation pressure at a fixed temperature.
7. EPA 608 Type II (High-Pressure)

   Under the EPA leak repair rules, what is the applicable leak rate that triggers repair for an industrial process refrigeration appliance with a full charge of 50 pounds or more of a class I or II refrigerant?

   A30 percent B20 percent C10 percent D35 percent
   Show answer

   Answer: A. 30 percent

   Industrial process refrigeration equipment is allowed to leak up to 30 percent of its full charge per year before the owner must repair, retrofit or retire it. Above that rate the leak repair clock starts. Source: 40 CFR 82.157(c)(2).

   • B: Wrong: 20 percent is the rate for commercial refrigeration.
   • C: Wrong: 10 percent is the rate for comfort cooling and other appliances.
   • D: Wrong: there is no 35 percent rate in the rule.
8. EPA 608 Type III (Low-Pressure)

   Under the Section 608 leak repair rule, what is the allowable annual leak rate for industrial process refrigeration equipment with a charge of 50 pounds or more?

   A35 percent of the full charge B10 percent of the full charge C30 percent of the full charge D20 percent of the full charge
   Show answer

   Answer: C. 30 percent of the full charge

   The current rule sets 30 percent per year for industrial process refrigeration. Once a leak rate calculation shows more than that, the owner must repair the leaks, or retrofit or retire the appliance. The 35 percent figure is the old pre-2019 trigger. Source: 40 CFR 82.157(c)(2).

   • A: 35 percent was the old trigger rate that applied only until January 1, 2019.
   • B: 10 percent is the rate for comfort cooling and other appliances, not industrial process.
   • D: 20 percent is the rate for commercial refrigeration, not industrial process.
9. EPA 608 Core

   Under the Section 608 definitions, a low-pressure appliance uses a refrigerant whose liquid-phase saturation pressure at 104 degrees F is:

   Abetween 170 and 355 psia Bbetween 45 and 170 psia Cbelow 45 psia Dabove 355 psia
   Show answer

   Answer: C. below 45 psia

   EPA draws the lines at 104 F: under 45 psia is low pressure, 45 to 170 is medium, 170 to 355 is high, and over 355 is very high. Chillers using R-11 or R-123 are the classic low-pressure examples. Source: 40 CFR 82.152 (definitions of high-, medium-, low- and very high-pressure appliance).

   • A: That range defines a high-pressure appliance.
   • B: That range defines a medium-pressure appliance.
   • D: That is the very high-pressure range.
10. EPA 608 Type I (Small Appliances)

    What can happen to chlorinated and fluorinated refrigerants when they contact an open flame or a very hot surface?

    AThey turn into harmless water vapor and carbon dioxide BThey break down into toxic and corrosive compounds CThey convert into a different refrigerant DThey become more stable and less toxic
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    Answer: B. They break down into toxic and corrosive compounds

    Halogenated refrigerants decompose in high heat into acids and other toxic gases. The breakdown products are far more hazardous than the refrigerant itself. Source: general refrigeration practice (refrigerant safety data).

    • A: Water vapor and CO2 are not the products; the breakdown makes acids and toxic gases.
    • C: Decomposition does not produce another usable refrigerant; it produces hazardous compounds.
    • D: Heat makes them less stable, and the products are more toxic.