EPA 608 HVAC Certification Practice Questions and Answers Updated
2026 | Complete EPA Section 608 Technician Certification Study Guide
with Verified Questions, Detailed Rationales, Core Certification, Type I,
Type II & Type III Refrigerant Handling, Refrigerant Recovery & Recycling,
Leak Detection, EPA Regulations, Ozone Protection, HVAC Safety &
Licensing Exam Prep
Question 1: What is the primary environmental concern associated with
chlorofluorocarbon (CFC) refrigerants?
A. They contribute to acid rain formation
B. They deplete stratospheric ozone through chlorine release
C. They cause immediate respiratory toxicity in humans
D. They increase ground-level ozone pollution
CORRECT ANSWER: B. They deplete stratospheric ozone through chlorine release
Rationale: CFCs contain chlorine atoms that, when released into the stratosphere by
ultraviolet radiation, catalytically destroy ozone molecules. One chlorine atom can
destroy thousands of ozone molecules, leading to thinning of the protective ozone layer
that shields Earth from harmful UV radiation.
www.epa.gov
Question 2: Which refrigerant classification has zero ozone depletion potential
(ODP)?
A. CFC (Chlorofluorocarbon)
B. HCFC (Hydrochlorofluorocarbon)
C. HFC (Hydrofluorocarbon)
D. Halon
CORRECT ANSWER: C. HFC (Hydrofluorocarbon)
Rationale: HFC refrigerants contain no chlorine or bromine atoms, which are the
elements responsible for ozone depletion. Therefore, HFCs have an ODP of zero.
However, many HFCs have high global warming potential (GWP), which is a separate
environmental concern.
www.epa.gov
Question 3: Under EPA Section 608, what is the maximum allowable annual leak
rate for commercial refrigeration systems containing more than 50 pounds of
refrigerant?
A. 10%
B. 15%
C. 25%
D. 35%
CORRECT ANSWER: D. 35%
,Rationale: EPA regulations require that commercial and industrial process refrigeration
systems containing more than 50 pounds of refrigerant must have leaks repaired if the
annual leak rate exceeds 35% of the total charge. For all other appliances with more
than 50 pounds, the threshold is 15%.
www.epa.gov
Question 4: What does the term "recovery" mean in the context of EPA Section 608
refrigerant management?
A. Processing refrigerant to meet ARI 700 virgin purity specifications
B. Cleaning refrigerant on-site for immediate reuse in the same system
C. Removing refrigerant from a system and storing it in an external container
D. Destroying refrigerant through high-temperature incineration
CORRECT ANSWER: C. Removing refrigerant from a system and storing it in an
external container
Rationale: Recovery is defined as the removal of refrigerant from a system and storage
in an external container without necessarily testing or processing it. This is distinct from
recycling (on-site cleaning) and reclamation (processing to virgin specifications at a
certified facility).
www.epa.gov
Question 5: Which color coding is standard for the compound (low-side) gauge on a
refrigerant manifold gauge set?
A. Red
B. Yellow
C. Blue
D. Green
CORRECT ANSWER: C. Blue
Rationale: Standard industry practice designates the compound gauge, which
measures low-side pressure and vacuum, as blue. The high-pressure gauge is typically
red, and the center service port hose is typically yellow. Proper gauge identification
prevents cross-contamination and ensures safe system servicing.
Question 6: What is the required evacuation level for a high-pressure appliance
containing less than 200 pounds of R-22 when using recovery equipment
manufactured on or after November 15, 1993?
A. 0 inches of Hg vacuum
B. 4 inches of Hg vacuum
C. 10 inches of Hg vacuum
D. 15 inches of Hg vacuum
CORRECT ANSWER: B. 4 inches of Hg vacuum
,Rationale: For high-pressure appliances with less than 200 pounds of HCFC-22, EPA
regulations require evacuation to 4 inches of Hg vacuum when using certified recovery
equipment manufactured on or after November 15, 1993. Equipment manufactured
before this date had less stringent requirements.
www.epa.gov
Question 7: Which of the following is NOT an acceptable method for leak detection
in refrigeration systems?
A. Electronic ultrasonic leak detector
B. Halide torch producing a green flame
C. Compressed oxygen pressurization with soap bubbles
D. Fluorescent dye injection with UV light inspection
CORRECT ANSWER: C. Compressed oxygen pressurization with soap bubbles
Rationale: Using compressed oxygen or air containing oxygen for leak testing is strictly
prohibited because mixing oxygen with refrigerant oil under pressure can create an
explosive mixture. Nitrogen is the only acceptable pressurizing gas for leak testing,
sometimes with a trace amount of refrigerant as a last resort.
www.epa.gov
Question 8: What is the primary purpose of a purge unit on a low-pressure
centrifugal chiller?
A. To recover refrigerant during system shutdown
B. To remove non-condensable gases and moisture that leak into the system
C. To compress refrigerant vapor for the condenser
D. To regulate evaporator water flow rate
CORRECT ANSWER: B. To remove non-condensable gases and moisture that leak
into the system
Rationale: Low-pressure chillers operate below atmospheric pressure, allowing air and
moisture to infiltrate through seals and gaskets. The purge unit automatically removes
these non-condensables from the top of the condenser to maintain system efficiency
and prevent corrosion. Excessive purging indicates a leak requiring repair.
www.epa.gov
Question 9: According to ASHRAE Standard 34, how are refrigerants classified
regarding toxicity?
A. Class 1 (non-toxic) and Class 2 (toxic)
B. Class A (lower toxicity) and Class B (higher toxicity)
C. Class I (safe) and Class II (hazardous)
D. Class X (acceptable) and Class Y (restricted)
CORRECT ANSWER: B. Class A (lower toxicity) and Class B (higher toxicity)
, Rationale: ASHRAE Standard 34 classifies refrigerants by toxicity (Class A = lower
toxicity, Class B = higher toxicity) and flammability (Class 1 = non-flammable, Class 2 =
mildly flammable, Class 3 = highly flammable). This creates safety designations like A1,
A2, B1, etc., to guide safe handling procedures.
www.epa.gov
Question 10: What is the maximum fill capacity for a refrigerant recovery cylinder
to allow for thermal expansion?
A. 60% of water capacity
B. 70% of water capacity
C. 80% of water capacity
D. 90% of water capacity
CORRECT ANSWER: C. 80% of water capacity
Rationale: Recovery cylinders must never be filled beyond 80% of their water capacity
to provide adequate vapor space for thermal expansion. Overfilling can cause
catastrophic cylinder rupture if the refrigerant temperature rises, as liquid refrigerant
expands significantly with heat. DOT regulations strictly enforce this limit.
www.epa.gov
Question 11: Which refrigerant is classified as a CFC?
A. R-22
B. R-134a
C. R-12
D. R-410A
CORRECT ANSWER: C. R-12
Rationale: R-12 (dichlorodifluoromethane) is a chlorofluorocarbon (CFC) containing
chlorine, fluorine, and carbon with no hydrogen. CFCs like R-12, R-11, and R-113 have
high ozone depletion potential and were phased out of production in the United States
by 1996 under the Clean Air Act.
www.epa.gov
Question 12: What is the definition of a "small appliance" under EPA Section 608
Type I certification?
A. Any appliance containing less than 10 pounds of refrigerant
B. Any appliance manufactured with 5 pounds or less of refrigerant, fully charged and
hermetically sealed at the factory
C. Any residential air conditioning unit under 2 tons capacity
D. Any appliance using HFC refrigerants only
CORRECT ANSWER: B. Any appliance manufactured with 5 pounds or less of
refrigerant, fully charged and hermetically sealed at the factory
2026 | Complete EPA Section 608 Technician Certification Study Guide
with Verified Questions, Detailed Rationales, Core Certification, Type I,
Type II & Type III Refrigerant Handling, Refrigerant Recovery & Recycling,
Leak Detection, EPA Regulations, Ozone Protection, HVAC Safety &
Licensing Exam Prep
Question 1: What is the primary environmental concern associated with
chlorofluorocarbon (CFC) refrigerants?
A. They contribute to acid rain formation
B. They deplete stratospheric ozone through chlorine release
C. They cause immediate respiratory toxicity in humans
D. They increase ground-level ozone pollution
CORRECT ANSWER: B. They deplete stratospheric ozone through chlorine release
Rationale: CFCs contain chlorine atoms that, when released into the stratosphere by
ultraviolet radiation, catalytically destroy ozone molecules. One chlorine atom can
destroy thousands of ozone molecules, leading to thinning of the protective ozone layer
that shields Earth from harmful UV radiation.
www.epa.gov
Question 2: Which refrigerant classification has zero ozone depletion potential
(ODP)?
A. CFC (Chlorofluorocarbon)
B. HCFC (Hydrochlorofluorocarbon)
C. HFC (Hydrofluorocarbon)
D. Halon
CORRECT ANSWER: C. HFC (Hydrofluorocarbon)
Rationale: HFC refrigerants contain no chlorine or bromine atoms, which are the
elements responsible for ozone depletion. Therefore, HFCs have an ODP of zero.
However, many HFCs have high global warming potential (GWP), which is a separate
environmental concern.
www.epa.gov
Question 3: Under EPA Section 608, what is the maximum allowable annual leak
rate for commercial refrigeration systems containing more than 50 pounds of
refrigerant?
A. 10%
B. 15%
C. 25%
D. 35%
CORRECT ANSWER: D. 35%
,Rationale: EPA regulations require that commercial and industrial process refrigeration
systems containing more than 50 pounds of refrigerant must have leaks repaired if the
annual leak rate exceeds 35% of the total charge. For all other appliances with more
than 50 pounds, the threshold is 15%.
www.epa.gov
Question 4: What does the term "recovery" mean in the context of EPA Section 608
refrigerant management?
A. Processing refrigerant to meet ARI 700 virgin purity specifications
B. Cleaning refrigerant on-site for immediate reuse in the same system
C. Removing refrigerant from a system and storing it in an external container
D. Destroying refrigerant through high-temperature incineration
CORRECT ANSWER: C. Removing refrigerant from a system and storing it in an
external container
Rationale: Recovery is defined as the removal of refrigerant from a system and storage
in an external container without necessarily testing or processing it. This is distinct from
recycling (on-site cleaning) and reclamation (processing to virgin specifications at a
certified facility).
www.epa.gov
Question 5: Which color coding is standard for the compound (low-side) gauge on a
refrigerant manifold gauge set?
A. Red
B. Yellow
C. Blue
D. Green
CORRECT ANSWER: C. Blue
Rationale: Standard industry practice designates the compound gauge, which
measures low-side pressure and vacuum, as blue. The high-pressure gauge is typically
red, and the center service port hose is typically yellow. Proper gauge identification
prevents cross-contamination and ensures safe system servicing.
Question 6: What is the required evacuation level for a high-pressure appliance
containing less than 200 pounds of R-22 when using recovery equipment
manufactured on or after November 15, 1993?
A. 0 inches of Hg vacuum
B. 4 inches of Hg vacuum
C. 10 inches of Hg vacuum
D. 15 inches of Hg vacuum
CORRECT ANSWER: B. 4 inches of Hg vacuum
,Rationale: For high-pressure appliances with less than 200 pounds of HCFC-22, EPA
regulations require evacuation to 4 inches of Hg vacuum when using certified recovery
equipment manufactured on or after November 15, 1993. Equipment manufactured
before this date had less stringent requirements.
www.epa.gov
Question 7: Which of the following is NOT an acceptable method for leak detection
in refrigeration systems?
A. Electronic ultrasonic leak detector
B. Halide torch producing a green flame
C. Compressed oxygen pressurization with soap bubbles
D. Fluorescent dye injection with UV light inspection
CORRECT ANSWER: C. Compressed oxygen pressurization with soap bubbles
Rationale: Using compressed oxygen or air containing oxygen for leak testing is strictly
prohibited because mixing oxygen with refrigerant oil under pressure can create an
explosive mixture. Nitrogen is the only acceptable pressurizing gas for leak testing,
sometimes with a trace amount of refrigerant as a last resort.
www.epa.gov
Question 8: What is the primary purpose of a purge unit on a low-pressure
centrifugal chiller?
A. To recover refrigerant during system shutdown
B. To remove non-condensable gases and moisture that leak into the system
C. To compress refrigerant vapor for the condenser
D. To regulate evaporator water flow rate
CORRECT ANSWER: B. To remove non-condensable gases and moisture that leak
into the system
Rationale: Low-pressure chillers operate below atmospheric pressure, allowing air and
moisture to infiltrate through seals and gaskets. The purge unit automatically removes
these non-condensables from the top of the condenser to maintain system efficiency
and prevent corrosion. Excessive purging indicates a leak requiring repair.
www.epa.gov
Question 9: According to ASHRAE Standard 34, how are refrigerants classified
regarding toxicity?
A. Class 1 (non-toxic) and Class 2 (toxic)
B. Class A (lower toxicity) and Class B (higher toxicity)
C. Class I (safe) and Class II (hazardous)
D. Class X (acceptable) and Class Y (restricted)
CORRECT ANSWER: B. Class A (lower toxicity) and Class B (higher toxicity)
, Rationale: ASHRAE Standard 34 classifies refrigerants by toxicity (Class A = lower
toxicity, Class B = higher toxicity) and flammability (Class 1 = non-flammable, Class 2 =
mildly flammable, Class 3 = highly flammable). This creates safety designations like A1,
A2, B1, etc., to guide safe handling procedures.
www.epa.gov
Question 10: What is the maximum fill capacity for a refrigerant recovery cylinder
to allow for thermal expansion?
A. 60% of water capacity
B. 70% of water capacity
C. 80% of water capacity
D. 90% of water capacity
CORRECT ANSWER: C. 80% of water capacity
Rationale: Recovery cylinders must never be filled beyond 80% of their water capacity
to provide adequate vapor space for thermal expansion. Overfilling can cause
catastrophic cylinder rupture if the refrigerant temperature rises, as liquid refrigerant
expands significantly with heat. DOT regulations strictly enforce this limit.
www.epa.gov
Question 11: Which refrigerant is classified as a CFC?
A. R-22
B. R-134a
C. R-12
D. R-410A
CORRECT ANSWER: C. R-12
Rationale: R-12 (dichlorodifluoromethane) is a chlorofluorocarbon (CFC) containing
chlorine, fluorine, and carbon with no hydrogen. CFCs like R-12, R-11, and R-113 have
high ozone depletion potential and were phased out of production in the United States
by 1996 under the Clean Air Act.
www.epa.gov
Question 12: What is the definition of a "small appliance" under EPA Section 608
Type I certification?
A. Any appliance containing less than 10 pounds of refrigerant
B. Any appliance manufactured with 5 pounds or less of refrigerant, fully charged and
hermetically sealed at the factory
C. Any residential air conditioning unit under 2 tons capacity
D. Any appliance using HFC refrigerants only
CORRECT ANSWER: B. Any appliance manufactured with 5 pounds or less of
refrigerant, fully charged and hermetically sealed at the factory
