EPA 608 Practice Test Core Question Answers 2026 [Online Free]

Last Updated on February 9, 2026

EPA 608 Practice Test Core Question Answers 2026[Online Free] EPA-approved test to earn the Section 608 Technician Certification core exam – free practice test. This sample online quiz test helps you test your knowledge and prepare for the 608 Technician Certification final exam.

EPA 608 Practice Test Core Question Answers 2026

EPA stands for	Environmental Protection Agency
Test Name	EPA Certification Test Prep
Section Name	608
Type of test	sample test
Type of question	multiple-choice
Answers availability	Yes
Total question	45
Time limit	N/A
Topics	EPA 608 Core
See also	EPA 608 Certification Exam Practice Test And Study Guide

EPA 608 Practice Test Core

These Practice questions are NOT the actual exam questions. The actual test contains four sections: the Core and sections I, II, and III. Each section includes twenty-five (25) multiple-choice questions. A minimum score of 70 percent (18 out of 25 correct).

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EPA 608 Exam Core Practice Test 1

EPA 608 Exam Test
Free Technician Certification Core Practice Test

1 / 45

1) What is a refrigerant recovery machine used for?

A) Removing refrigerant from a system for storage or disposal

B) Adding refrigerant to a system

C) Compressing refrigerant

D) Heating refrigerant

A refrigerant recovery machine is used to remove refrigerant from a system for storage or disposal.

2 / 45

2) What type of refrigerant is R-134a classified as?

A) CFC

B) HCFC

C) HFC

D) HFO

R-134a is classified as a hydrofluorocarbon (HFC).

3 / 45

3) How big should the vacuum hoses be in relation to the pump intake connection?

A) One size larger than pump intake connection

B) Equal to or larger than the pump intake connection

C) One and a half size larger than pump intake connection

D) None of the above

Vacuum hoses should be equal to or larger than the pump intake connection to ensure proper evacuation.

4 / 45

4) What must be done before opening a refrigeration system for maintenance?

A) Evacuate the system

B) Recover the refrigerant

C) Charge the system

D) Pressurize the system

The refrigerant must be recovered before opening a refrigeration system for maintenance.

5 / 45

5) What is the primary purpose of a filter-drier in a refrigeration system?

A) Remove moisture and contaminants

B) Reduce pressure

C) Control refrigerant flow

D) Increase refrigerant temperature

The primary purpose of a filter-drier is to remove moisture and contaminants from the refrigeration system.

6 / 45

6) What is a common method for leak detection in refrigeration systems?

A) Using a stethoscope

B) Electronic leak detector

C) Water pressure test

D) Thermometer

An electronic leak detector is a common method for detecting leaks in refrigeration systems.

7 / 45

7) What is an ozone molecule made of?

A) Refrigerant

B) Ammonia

C) Three oxygen atoms (O3)

D) Oxygen and ammonia

An ozone molecule is composed of three oxygen atoms (O3). It is an important component of the stratosphere, protecting the Earth from harmful UV radiation.

8 / 45

8) What are the four factors that affect the evacuation time?

A) Size of equipment being evacuated

B) Ambient temperature, Amount of moisture

C) Capacity of vacuum pump and suction line

D) All of the above

Evacuation time is affected by the size of the equipment, ambient temperature, amount of moisture, and capacity of the vacuum pump and suction line.

9 / 45

9) What safety device is used to prevent over-pressurization in a refrigeration system?

A) Thermostat

B) Pressure gauge

C) Pressure relief valve

D) Expansion valve

A pressure relief valve is used to prevent over-pressurization in a refrigeration system.

10 / 45

10) How long and what diameter should the piping connection to the vacuum pump be?

A) 3 feet and 3/8”

B) 2.5 feet and 3/8”

C) 2 feet and 3/8”

D) As short in length as possible and as wide in diameter as possible

Piping connections to the vacuum pump should be as short as possible and have a wide diameter to facilitate efficient evacuation.

11 / 45

11) What do high head pressure readings on a gauge set indicate?

A) Air in the system

B) Low refrigerant

C) Overcharged refrigerant

D) Leaking refrigerant

High head pressure readings on a gauge set can indicate the presence of air in the system.

12 / 45

12) What is the leading cause of refrigeration accidents leading to death?

A) Phosgene gas inhalation

B) Oxygen deprivation

C) Freezing to death

D) Electrocution

The leading cause of refrigeration accidents leading to death is oxygen deprivation.

13 / 45

13) Which refrigerant is a CFC?

A) R-134A

B) R-123

C) R-22

D) R-12

R-12 is a chlorofluorocarbon (CFC) refrigerant that was commonly used before being phased out due to its high ozone-depletion potential.

14 / 45

14) Name the refrigerant types that belong to CFCs, HCFCs, and HFCs:

A) CFC R-11, R-12, R-500

B) HCFC R-22, R-123

C) HFC R-134a

D) All of the above are correct

CFCs include refrigerants like R-11, R-12, and R-500. HCFCs include R-22 and R-123. HFCs include R-134a. All these classifications are correct.

15 / 45

15) What is the ozone layer and why is it important to us on Earth?

A) Thin layer of R-22 in the atmosphere that filters UV.

B) Protective shield for Earth from the sun’s harmful ultraviolet (UV) rays in the stratosphere layer that extends about 6 to 30 miles above earth.

C) Thin layer of CFC and HCFC in the atmosphere that filters UV.

D) Protective layer that shields UV in the Troposphere

The ozone layer is a protective shield in the stratosphere that absorbs most of the sun’s harmful ultraviolet radiation, preventing it from reaching the Earth's surface.

16 / 45

16) What type of oil is commonly used with R-22 refrigerant?

A) Mineral oil

B) Polyolester oil

C) Alkylbenzene oil

D) PAG oil

Mineral oil is commonly used with R-22 refrigerant.

17 / 45

17) What are the variables that affect the recovery rate?

A) Size of refrigeration system and recovery equipment

B) Size of suction hose

C) Temperatures

D) All of the above

Recovery rate is influenced by the size of the system, recovery equipment, suction hose, and temperatures.

18 / 45

18) What personal protective equipment should you wear when handling refrigerants?

A) Safety glasses

B) Butyl-lined protective gloves

C) Safety shoes

D) All the above

When handling refrigerants, it is important to wear safety glasses, butyl-lined protective gloves, and safety shoes for protection.

19 / 45

19) What is the purpose of the condenser in an HVAC system?

A) Absorb heat from the air

B) Reject heat from the refrigerant

C) Compress the refrigerant

D) Control the flow of refrigerant

The condenser's purpose is to reject heat from the refrigerant, allowing it to condense from a vapor to a liquid.

20 / 45

20) After recovery, what are nitrogen and a filter drier used for?

A) Dry the system.

B) Filter dryer is used to clean the nitrogen before removal

C) Flush debris and trap any debris

D) All of the above

21 / 45

21) Why is it important to regularly check and repair refrigerant leaks?

A) To prevent environmental harm and ensure system efficiency

B) To increase refrigerant levels

C) To avoid system shutdowns

D) To reduce energy consumption

Regularly checking and repairing refrigerant leaks is important to prevent environmental harm and ensure system efficiency.

22 / 45

22) If you smell a strong odor during recovery, what is most likely the problem?

A) Compressor has burned out

B) Sour gas

C) Pressure is too high

D) Recovery machine is overloaded

A strong odor during recovery likely indicates a compressor burnout.

23 / 45

23) Why is it necessary to dehydrate a refrigeration system?

A) Remove water from a hydrostatic pressure test

B) Remove debris from the system

C) Remove ice contaminates

D) Remove water and water vapor contaminating the system

Dehydration is essential to remove water and water vapor that can contaminate the system.

24 / 45

24) Why should refrigerant cylinders not be filled more than 80%?

A) To allow for expansion of the refrigerant

B) To prevent leaks

C) To ensure proper pressure

D) To avoid contamination

Refrigerant cylinders should not be filled more than 80% to allow for the expansion of the refrigerant.

25 / 45

25) What must be done before starting evacuation?

A) Install nitrogen

B) Install dryer

C) Recover all refrigerant

D) Install sight glass

All refrigerant must be recovered before starting the evacuation process.

26 / 45

26) What safety precaution should be taken when working with refrigerants?

A) Wearing hearing protection

B) Wearing personal protective equipment (PPE)

C) Using a ladder

D) Wearing a harness

When working with refrigerants, it is important to wear personal protective equipment (PPE) for safety.

27 / 45

27) Describe how one Chlorine atom can destroy 100,000 ozone molecules.

A) Chlorine releases one of the oxygen atoms and forms two O2 oxygen molecules, leaving the chlorine molecule free to attack another ozone molecule and repeat the process.

B) Chlorine locks up the ozone molecule and then goes after another.

C) Chlorine converts the ozone to bromine and then attacks more ozone molecules.

D) Chlorine can bleach 100,000 ozone molecules before it weakens.

One chlorine atom can destroy many ozone molecules by repeatedly breaking apart ozone (O3) molecules and forming oxygen molecules (O2), with the chlorine atom being released and able to continue the cycle.

28 / 45

28) When should the measurement of vacuum for a system be done and how do we know when dehydration is complete?

A) With the system isolated and vacuum pump turned on. Dehydration is considered complete when the vacuum gauge shows that have reached and held the required finished vacuum

B) With the system open and vacuum pump turned off. Dehydration is considered complete when the vacuum gauge shows that have reached and held the required finished vacuum

C) With the system isolated and vacuum pump turned off. Dehydration is considered complete when the vacuum gauge shows that have reached and held the required finished vacuum for one minute

D) With the system isolated and vacuum pump turned off. Dehydration is considered complete when the vacuum gauge shows that have reached and held the required finished vacuum

Dehydration is considered complete when the vacuum gauge shows that the required vacuum has been reached and held for one minute with the system isolated and the vacuum pump turned off.

29 / 45

29) Which of the following is considered a high-pressure refrigerant?

A) R-11

B) R-123

C) R-22

D) R-134a

R-22 is considered a high-pressure refrigerant.

30 / 45

30) As of what date did it become unlawful to release Class 1 and Class II refrigerants to the atmosphere?

A) July 1, 1992

B) July 1, 1993

C) November 14, 1994

D) January 1, 1996

Releasing Class 1 and Class II refrigerants to the atmosphere became unlawful on November 14, 1994, as part of the EPA's effort to reduce the depletion of the ozone layer.

31 / 45

31) What are the requirements under ASHRAE standard 15-1994?

A) Requires a refrigerant sensor that will sound an alarm and automatically start a ventilation system in occupied equipment rooms where refrigerant (regardless of refrigerant type) from a leak will concentrate.

B) Requires a refrigerant sensor that will sound an alarm and automatically start a ventilation system in occupied equipment rooms where R-123 from a leak will concentrate

C) Requires a refrigerant sensor that will sound an alarm and automatically start a ventilation system in occupied equipment rooms where R-11 from a leak will concentrate

D) Requires a refrigerant sensor that will sound an alarm and automatically start a ventilation system in occupied equipment rooms where CFCs from a leak will concentrate

ASHRAE standard 15-1994 requires a refrigerant sensor that will sound an alarm and start a ventilation system in occupied equipment rooms where refrigerant from a leak will concentrate, regardless of the refrigerant type.

32 / 45

32) What happens if moisture is left in an operating refrigeration system?

A) Freezes up

B) Create highly corrosive and toxic acids

C) Increases head pressure

D) Reduces head pressure

Moisture can create corrosive and toxic acids, causing damage to the system.

33 / 45

33) What should be done if a refrigerant cylinder shows signs of rust or damage?

A) Remove from service and properly dispose of it

B) Refill it with refrigerant

C) Use it only for recovery

D) Paint over the rust

A refrigerant cylinder showing signs of rust or damage should be removed from service and properly disposed of.

34 / 45

34) Can you increase the temperature of a refrigeration system for evacuation and if so, what purpose does it have?

A) Yes. Decrease the evacuation time by increasing pressure

B) No. It increases time by increasing pressure

C) No. Creates danger of explosion

D) None of the above

Increasing the temperature of a refrigeration system can decrease evacuation time by increasing pressure.

35 / 45

35) What is the name of the atom that attacks ozone molecules?

A) CFC atoms

B) HCFC atoms

C) Chlorine and bromine atoms emitted into the atmosphere

D) a and b

Chlorine and bromine atoms, released from CFCs and HCFCs, are the primary agents that destroy ozone molecules in the stratosphere.

36 / 45

36) What is the function of the metering device in a refrigeration system?

A) Compress the refrigerant

B) Absorb heat from the air

C) Control the flow of refrigerant into the evaporator

D) Reject heat from the refrigerant

The metering device controls the flow of refrigerant into the evaporator.

37 / 45

37) Why is it important to use a vacuum pump when evacuating a refrigeration system?

A) To add refrigerant

B) To remove air and moisture

C) To increase pressure

D) To decrease temperature

A vacuum pump is used to remove air and moisture from a refrigeration system during evacuation.

38 / 45

38) Which refrigerant is an HFC?

A) R-134A

B) R-123

C) R-22

D) R-12

R-134A is a hydrofluorocarbon (HFC) refrigerant, which does not contain chlorine and therefore does not deplete the ozone layer.

39 / 45

39) The atom found in CFC and HCFC refrigerants that destroys ozone in the stratosphere is?

A) Fluorine

B) Carbon

C) Hydrogen

D) Chlorine Answer

Chlorine atoms released from CFCs and HCFCs in the stratosphere can destroy ozone molecules, contributing to the depletion of the ozone layer.

40 / 45

40) What is the primary environmental concern associated with refrigerants?

A) Noise pollution

B) Ozone depletion and global warming

C) Water contamination

D) Soil erosion

The primary environmental concern associated with refrigerants is ozone depletion and global warming.

41 / 45

41) Which refrigerant contains no chlorine?

A) R-134A

B) R-123

C) R-22

D) R-12

R-134A is an HFC refrigerant, which means it does not contain chlorine and therefore does not contribute to ozone depletion.

42 / 45

42) Which component is responsible for absorbing heat in a refrigeration system?

A) Condenser

B) Compressor

C) Expansion valve

D) Evaporator

The evaporator is responsible for absorbing heat in a refrigeration system.

43 / 45

43) What are the risks of inhaling (breathing in) refrigerants?

A) Refrigerants can be deadly if inhaled or allowed to be heated

B) Refrigerants inert and harmless if inhaled

C) Refrigerants are only dangerous if heated

D) Refrigerants can be safe if heated

Inhaling refrigerants can be deadly, especially if they are heated and decompose into toxic gases.

44 / 45

44) For accurate vacuum readings, where should the vacuum gauge be located?

A) Close to the vacuum pump

B) Between the vacuum pump and unit

C) As far as possible from the vacuum pump

D) On the vacuum pump

The vacuum gauge should be located as far as possible from the vacuum pump for accurate readings.

45 / 45

45) Why is it important to have faster recovery?

A) Taking longer increases chance of emissions of the refrigerants to the atmosphere

B) Faster recovery saves energy

C) Faster recovery removes oil

D) All of the above

Faster recovery reduces the risk of refrigerant emissions to the atmosphere.

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