EPA Section 608 Universal Certification Exam |
Complete Practice QUESTIONs, Verified Answers &
Detailed Rationales (2026/2027)
QUESTION 1 What substance found in the stratosphere is primarily
responsible for the destruction of ozone molecules caused by man-
made CFCs and HCFCs?
A. Carbon dioxide
B. Chlorine
C. Nitrogen
D. Hydrogen
Correct Answer: B. Chlorine
Detailed Rationale: CFCs and HCFCs release chlorine atoms when
exposed to ultraviolet radiation in the stratosphere. A single chlorine
atom can destroy up to 100,000 ozone molecules.
QUESTION 2 Under the Clean Air Act Section 608, what is prohibited
regarding ozone-depleting and substitute refrigerants?
A. Using them in commercial refrigerators
B. Venting or intentionally releasing regulated refrigerants during
maintenance, service, repair, or disposal
C. Transporting them across state lines in approved cylinders
,D. Reclaiming them to ARI-700 standards
Correct Answer: B. Venting or intentionally releasing regulated
refrigerants during maintenance, service, repair, or disposal
Detailed Rationale: EPA Section 608 explicitly prohibits the intentional
venting of ozone-depleting CFCs, HCFCs, and their substitute
refrigerants (such as HFCs and HFOs) into the atmosphere.
QUESTION 3 What is the definition of "Reclamation" according to EPA
standards?
A. Passing refrigerant through a filter-drier to remove moisture
B. Extracting refrigerant from an appliance and loading it into an
uncertified container
C. Processing recovered refrigerant to new-product specifications (ARI-
700 purity standards) through chemical analysis
D. Venting old refrigerant outdoors before charging a new system
Correct Answer: C. Processing recovered refrigerant to new-product
specifications (ARI-700 purity standards) through chemical analysis
Detailed Rationale: Reclamation requires chemical analysis to ensure
the refrigerant meets strict ARI-700 purity standards, making it
equivalent to virgin refrigerant. Recycling only removes moisture and
acidity via filter-driers.
QUESTION 4 What is required before disposing of a disposable (non-
refillable) refrigerant cylinder?
A. Paint the cylinder bright red
,B. Recover any remaining refrigerant to at least 0 psig, render the
cylinder useless, and recycle the metal
C. Fill the cylinder completely with compressed air
D. Leave the valve wide open outdoors
Correct Answer: B. Recover any remaining refrigerant to at least 0 psig,
render the cylinder useless, and recycle the metal
Detailed Rationale: EPA regulations require disposable cylinders to be
completely evacuated (0 psig or lower), punctured or rendered
unusable, and sent to a metal recycler.
QUESTION 5 Which type of refrigerant contains chlorine, fluorine, and
carbon, and has the highest ozone depletion potential (ODP)?
A. Hydrofluorocarbons (HFCs)
B. Hydrochlorofluorocarbons (HCFCs)
C. Chlorofluorocarbons (CFCs)
D. Hydrofluoroolefins (HFOs)
Correct Answer: C. Chlorofluorocarbons (CFCs)
Detailed Rationale: CFCs contain chlorine and are extremely stable in
the lower atmosphere, allowing them to reach the stratosphere where
they release chlorine and severely deplete the ozone layer.
QUESTION 6 What safety precaution must always be followed when
working with refrigerant cylinders?
A. Heat cylinders with an open torch to speed up recovery
, B. Never apply an open flame to a refrigerant cylinder and never exceed
maximum fill levels
C. Fill recovery cylinders to 100% liquid capacity
D. Pressurize cylinders with oxygen for leak testing
Correct Answer: B. Never apply an open flame to a refrigerant cylinder
and never exceed maximum fill levels
Detailed Rationale: Applying heat or overfilling cylinders can cause
catastrophic tank failure and explosion. Recovery tanks must never be
filled beyond 80% of their liquid capacity by weight.
QUESTION 7 Which gas should be used to leak-test a refrigeration
system safely?
A. Compressed oxygen
B. Dry nitrogen
C. Acetylene gas
D. Raw ambient air
Correct Answer: B. Dry nitrogen
Detailed Rationale: Dry nitrogen is an inert gas that will not react with
refrigerant oil or form explosive mixtures. Oxygen and compressed air
must never be used to pressurize refrigerant systems.
QUESTION 8 What color is conventionally used to designate the high-
pressure gauge on a standard manifold gauge set?
A. Blue
B. Yellow
Complete Practice QUESTIONs, Verified Answers &
Detailed Rationales (2026/2027)
QUESTION 1 What substance found in the stratosphere is primarily
responsible for the destruction of ozone molecules caused by man-
made CFCs and HCFCs?
A. Carbon dioxide
B. Chlorine
C. Nitrogen
D. Hydrogen
Correct Answer: B. Chlorine
Detailed Rationale: CFCs and HCFCs release chlorine atoms when
exposed to ultraviolet radiation in the stratosphere. A single chlorine
atom can destroy up to 100,000 ozone molecules.
QUESTION 2 Under the Clean Air Act Section 608, what is prohibited
regarding ozone-depleting and substitute refrigerants?
A. Using them in commercial refrigerators
B. Venting or intentionally releasing regulated refrigerants during
maintenance, service, repair, or disposal
C. Transporting them across state lines in approved cylinders
,D. Reclaiming them to ARI-700 standards
Correct Answer: B. Venting or intentionally releasing regulated
refrigerants during maintenance, service, repair, or disposal
Detailed Rationale: EPA Section 608 explicitly prohibits the intentional
venting of ozone-depleting CFCs, HCFCs, and their substitute
refrigerants (such as HFCs and HFOs) into the atmosphere.
QUESTION 3 What is the definition of "Reclamation" according to EPA
standards?
A. Passing refrigerant through a filter-drier to remove moisture
B. Extracting refrigerant from an appliance and loading it into an
uncertified container
C. Processing recovered refrigerant to new-product specifications (ARI-
700 purity standards) through chemical analysis
D. Venting old refrigerant outdoors before charging a new system
Correct Answer: C. Processing recovered refrigerant to new-product
specifications (ARI-700 purity standards) through chemical analysis
Detailed Rationale: Reclamation requires chemical analysis to ensure
the refrigerant meets strict ARI-700 purity standards, making it
equivalent to virgin refrigerant. Recycling only removes moisture and
acidity via filter-driers.
QUESTION 4 What is required before disposing of a disposable (non-
refillable) refrigerant cylinder?
A. Paint the cylinder bright red
,B. Recover any remaining refrigerant to at least 0 psig, render the
cylinder useless, and recycle the metal
C. Fill the cylinder completely with compressed air
D. Leave the valve wide open outdoors
Correct Answer: B. Recover any remaining refrigerant to at least 0 psig,
render the cylinder useless, and recycle the metal
Detailed Rationale: EPA regulations require disposable cylinders to be
completely evacuated (0 psig or lower), punctured or rendered
unusable, and sent to a metal recycler.
QUESTION 5 Which type of refrigerant contains chlorine, fluorine, and
carbon, and has the highest ozone depletion potential (ODP)?
A. Hydrofluorocarbons (HFCs)
B. Hydrochlorofluorocarbons (HCFCs)
C. Chlorofluorocarbons (CFCs)
D. Hydrofluoroolefins (HFOs)
Correct Answer: C. Chlorofluorocarbons (CFCs)
Detailed Rationale: CFCs contain chlorine and are extremely stable in
the lower atmosphere, allowing them to reach the stratosphere where
they release chlorine and severely deplete the ozone layer.
QUESTION 6 What safety precaution must always be followed when
working with refrigerant cylinders?
A. Heat cylinders with an open torch to speed up recovery
, B. Never apply an open flame to a refrigerant cylinder and never exceed
maximum fill levels
C. Fill recovery cylinders to 100% liquid capacity
D. Pressurize cylinders with oxygen for leak testing
Correct Answer: B. Never apply an open flame to a refrigerant cylinder
and never exceed maximum fill levels
Detailed Rationale: Applying heat or overfilling cylinders can cause
catastrophic tank failure and explosion. Recovery tanks must never be
filled beyond 80% of their liquid capacity by weight.
QUESTION 7 Which gas should be used to leak-test a refrigeration
system safely?
A. Compressed oxygen
B. Dry nitrogen
C. Acetylene gas
D. Raw ambient air
Correct Answer: B. Dry nitrogen
Detailed Rationale: Dry nitrogen is an inert gas that will not react with
refrigerant oil or form explosive mixtures. Oxygen and compressed air
must never be used to pressurize refrigerant systems.
QUESTION 8 What color is conventionally used to designate the high-
pressure gauge on a standard manifold gauge set?
A. Blue
B. Yellow
