EPA 608 CORE Exam Study Guide
– Practice Questions with Verified
Answers. GRADED A+. Latest
2026/2027 Update
What does ozone in the stratosphere above the earth consist of?
a. Molecules containing 2 oxygen atoms.
b. Molecules containing 3 oxygen atoms.
c. Molecules containing 4 oxygen atoms.
d. Molecules containing 5 oxygen atoms - Answer✔✔-b. Molecules containing
3 oxygen atoms.
Which of the following refrigerants has the lowest global warming potential?
a. R-134a
b. R-407C
c. R-410A
d. R-600a - Answer✔✔-d. R-600a
Which of the following gases is used as the baseline
measurement for global warming potential?
a. Ammonia
b. Carbon Dioxide
,c. CFC-12
d. Propane - Answer✔✔-b. Carbon Dioxide
Which type of refrigerant typically has the lowest global warming potential?
a. HCFCs
b. HFOs
c. HFCs
d. All are equal - Answer✔✔-b. HFOs
What is the state of refrigerant entering the compressor of a refrigeration
system?
a. Low pressure subcooled liquid
b. Low pressure superheated vapor
c. High pressure subcooled liquid
d. High pressure subcooled vapor - Answer✔✔-b. Low pressure superheated
vapor
How does the global warming potential of R-410A compare to that of carbon
dioxide?
a. It is lower.
b. They are equal.
c. It is hundreds of times greater.
d. It is thousands of times greater. - Answer✔✔-d. It is thousands of times
greater.
How do the global warming potentials of isobutane
,(R-600a), propane (R-290), and R-441A compare to
the GWPs of HFC-134a, R404A, and R-410A?
a. They are significantly higher.
b. They are significantly lower.
c. They are approximately equal
d. They are slightly higher. - Answer✔✔-b. They are significantly lower.
What are the characteristics of hydrofluoroolefins (HFOs)?
a. Non-ozone depleting and have high global warming potentials.
b. Non-ozone depleting and have low global warming potentials.
c. Ozone depleting and have high global warming potentials.
d. Ozone depleting and have low global warming potentials. - Answer✔✔-b.
Non-ozone depleting and have low global
warming potentials.
Why are HFO refrigerants less flammable than
hydrocarbon refrigerants?
a. They contain chlorine.
b. They contain bromine.
c. They contain fluorine.
d. They contain carbon. - Answer✔✔-c. They contain fluorine.
Which of the following refrigerants is an HFO?
a. R-1234yf
b. R-123
, c. R-134a
d. All three are HFOs - Answer✔✔-a. R-1234yf
What characteristics of HFC refrigerants make them damaging to the
environment?
a. They are toxic to plants and animals at low doses.
b. They contain chlorine which damages the ozone layer.
c. They have high Ozone Depletion Potential (ODP)
d. They can have very high global warming potentials. - Answer✔✔-d. They can
have very high global warming
potentials.
Why are some of the hydrofluoroolefins classified as A2L?
a. They have toxicity characteristics.
b. They are less flammable than hydrocarbon refrigerants, but most are still
mildly flammable.
c. They are prohibited for use in the U.S.
d. They have ozone depleting potentials and have
low global warming potentials. - Answer✔✔-b. They are less flammable than
hydrocarbon refrigerants, but most are still mildly flammable.
How many ozone molecules can each chlorine atom in the stratosphere
destroy?
a. 1,000 molecules
b. 100,000 molecules
c. 100,000,000 molecules
– Practice Questions with Verified
Answers. GRADED A+. Latest
2026/2027 Update
What does ozone in the stratosphere above the earth consist of?
a. Molecules containing 2 oxygen atoms.
b. Molecules containing 3 oxygen atoms.
c. Molecules containing 4 oxygen atoms.
d. Molecules containing 5 oxygen atoms - Answer✔✔-b. Molecules containing
3 oxygen atoms.
Which of the following refrigerants has the lowest global warming potential?
a. R-134a
b. R-407C
c. R-410A
d. R-600a - Answer✔✔-d. R-600a
Which of the following gases is used as the baseline
measurement for global warming potential?
a. Ammonia
b. Carbon Dioxide
,c. CFC-12
d. Propane - Answer✔✔-b. Carbon Dioxide
Which type of refrigerant typically has the lowest global warming potential?
a. HCFCs
b. HFOs
c. HFCs
d. All are equal - Answer✔✔-b. HFOs
What is the state of refrigerant entering the compressor of a refrigeration
system?
a. Low pressure subcooled liquid
b. Low pressure superheated vapor
c. High pressure subcooled liquid
d. High pressure subcooled vapor - Answer✔✔-b. Low pressure superheated
vapor
How does the global warming potential of R-410A compare to that of carbon
dioxide?
a. It is lower.
b. They are equal.
c. It is hundreds of times greater.
d. It is thousands of times greater. - Answer✔✔-d. It is thousands of times
greater.
How do the global warming potentials of isobutane
,(R-600a), propane (R-290), and R-441A compare to
the GWPs of HFC-134a, R404A, and R-410A?
a. They are significantly higher.
b. They are significantly lower.
c. They are approximately equal
d. They are slightly higher. - Answer✔✔-b. They are significantly lower.
What are the characteristics of hydrofluoroolefins (HFOs)?
a. Non-ozone depleting and have high global warming potentials.
b. Non-ozone depleting and have low global warming potentials.
c. Ozone depleting and have high global warming potentials.
d. Ozone depleting and have low global warming potentials. - Answer✔✔-b.
Non-ozone depleting and have low global
warming potentials.
Why are HFO refrigerants less flammable than
hydrocarbon refrigerants?
a. They contain chlorine.
b. They contain bromine.
c. They contain fluorine.
d. They contain carbon. - Answer✔✔-c. They contain fluorine.
Which of the following refrigerants is an HFO?
a. R-1234yf
b. R-123
, c. R-134a
d. All three are HFOs - Answer✔✔-a. R-1234yf
What characteristics of HFC refrigerants make them damaging to the
environment?
a. They are toxic to plants and animals at low doses.
b. They contain chlorine which damages the ozone layer.
c. They have high Ozone Depletion Potential (ODP)
d. They can have very high global warming potentials. - Answer✔✔-d. They can
have very high global warming
potentials.
Why are some of the hydrofluoroolefins classified as A2L?
a. They have toxicity characteristics.
b. They are less flammable than hydrocarbon refrigerants, but most are still
mildly flammable.
c. They are prohibited for use in the U.S.
d. They have ozone depleting potentials and have
low global warming potentials. - Answer✔✔-b. They are less flammable than
hydrocarbon refrigerants, but most are still mildly flammable.
How many ozone molecules can each chlorine atom in the stratosphere
destroy?
a. 1,000 molecules
b. 100,000 molecules
c. 100,000,000 molecules
