EPA 608 HVAC Certification Practice Exam
Questions and Answers Updated 2026 | Complete
EPA Section 608 Study Guide with Verified
Questions, Detailed Rationales, Refrigerant
Handling, Recovery & Recycling Procedures, HVAC
System Safety, Environmental Regulations, Leak
Detection, Certification Core, Type I, Type II, Type
III Exam Prep & Technician Compliance Training
Question 1: Which atmospheric layer contains the majority of Earth's protective
ozone that filters harmful ultraviolet radiation?
A. Troposphere B. Mesosphere C. Stratosphere D. Thermosphere
CORRECT ANSWER: C. Stratosphere
Rationale: The stratosphere, located approximately 6-30 miles above Earth's surface,
contains approximately 90% of atmospheric ozone. This ozone layer absorbs 97-99% of
the Sun's harmful ultraviolet (UV-B and UV-C) radiation, protecting life on Earth from
DNA damage, skin cancer, and other health effects.
www.epa.gov
Question 2: What is the primary mechanism by which chlorine from CFC
refrigerants destroys stratospheric ozone?
A. Chlorine directly bonds with ozone to form stable compounds B. Chlorine acts as a
catalyst, repeatedly breaking down ozone molecules without being consumed C.
Chlorine absorbs UV radiation that would otherwise create ozone D. Chlorine displaces
oxygen atoms in ozone molecules permanently
CORRECT ANSWER: B. Chlorine acts as a catalyst, repeatedly breaking down ozone
molecules without being consumed
Rationale: A single chlorine atom can destroy over 100,000 ozone molecules through a
catalytic cycle. Chlorine reacts with ozone (O₃) to form chlorine monoxide (ClO) and
oxygen (O₂). ClO then reacts with atomic oxygen to regenerate chlorine, allowing the
cycle to repeat. This catalytic nature makes chlorine extremely destructive to the ozone
layer.
www.epa.gov
Question 3: Which refrigerant classification contains chlorine, fluorine, and carbon
but NO hydrogen?
A. HFC (Hydrofluorocarbon) B. HCFC (Hydrochlorofluorocarbon) C. CFC
(Chlorofluorocarbon) D. PFC (Perfluorocarbon)
CORRECT ANSWER: C. CFC (Chlorofluorocarbon)
,Rationale: CFCs contain only chlorine, fluorine, and carbon atoms. The absence of
hydrogen makes CFCs extremely stable in the lower atmosphere, allowing them to
persist long enough to reach the stratosphere where UV radiation breaks them down,
releasing ozone-depleting chlorine. Examples include R-11, R-12, and R-113.
www.epa.gov
Question 4: Which of the following refrigerants is classified as an HCFC?
A. R-12 B. R-22 C. R-134a D. R-410A
CORRECT ANSWER: B. R-22
Rationale: R-22 (chlorodifluoromethane) is an HCFC because it contains hydrogen,
chlorine, fluorine, and carbon. HCFCs have lower ozone depletion potential (ODP) than
CFCs because the hydrogen atom makes them more reactive in the lower atmosphere,
reducing the amount that reaches the stratosphere. R-22 has an ODP of 0.055.
www.epa.gov
Question 5: What does ODP stand for in refrigerant environmental impact
assessment?
A. Ozone Depletion Potential B. Ozone Destruction Parameter C. Ozone Damage
Percentage D. Ozone Degradation Profile
CORRECT ANSWER: A. Ozone Depletion Potential
Rationale: Ozone Depletion Potential (ODP) is a relative measure comparing a
substance's ability to destroy stratospheric ozone compared to CFC-11, which is
assigned an ODP of 1.0. CFCs typically have ODPs of 0.6-1.0, HCFCs range from 0.01-
0.1, and HFCs have an ODP of zero because they contain no chlorine.
www.epa.gov
Question 6: Which international treaty established the framework for phasing out
ozone-depleting substances globally?
A. Kyoto Protocol B. Paris Agreement C. Montreal Protocol D. Clean Air Accord
CORRECT ANSWER: C. Montreal Protocol
Rationale: The Montreal Protocol on Substances that Deplete the Ozone Layer,
adopted in 1987, is an international environmental agreement that regulates the
production and consumption of ozone-depleting substances. It has been ratified by all
198 UN member states and is considered one of the most successful environmental
treaties ever implemented.
www.epa.gov
Question 7: Under Section 608 of the Clean Air Act, what is the maximum civil
penalty for knowingly venting prohibited refrigerants?
,A. $10,000 per day per violation B. $25,000 per day per violation C. $37,500 per day per
violation (as adjusted for inflation) D. $100,000 per day per violation
CORRECT ANSWER: C. $37,500 per day per violation (as adjusted for inflation)
Rationale: The EPA adjusts civil penalties for inflation periodically. As of recent
adjustments, the maximum civil penalty for violations of Section 608 refrigerant
management regulations, including illegal venting, is $37,500 per day per violation.
Criminal penalties may also apply for knowing violations.
www.epa.gov
Question 8: Which refrigerant type has ZERO ozone depletion potential?
A. CFC B. HCFC C. HFC D. All of the above
CORRECT ANSWER: C. HFC
Rationale: Hydrofluorocarbons (HFCs) contain hydrogen, fluorine, and carbon but no
chlorine or bromine. Since chlorine and bromine are the elements responsible for ozone
depletion, HFCs have an ODP of zero. However, many HFCs have high global warming
potential (GWP), leading to ongoing regulatory efforts to phase down their use.
www.epa.gov
Question 9: What is the primary health concern associated with increased
ultraviolet radiation reaching Earth's surface due to ozone depletion?
A. Respiratory illness B. Skin cancer and cataracts C. Cardiovascular disease D.
Neurological disorders
CORRECT ANSWER: B. Skin cancer and cataracts
Rationale: Increased UV-B radiation due to ozone depletion is directly linked to higher
rates of skin cancers (including melanoma), premature skin aging, and cataracts. UV
radiation also suppresses immune system function and can damage terrestrial and
aquatic ecosystems. Protecting the ozone layer is critical for public health.
www.epa.gov
Question 10: Which of the following is NOT a prohibited venting exception under
EPA Section 608 regulations?
A. De minimis releases during good-faith recovery efforts B. Normal operational
releases from mechanical purging on low-pressure chillers C. Release of refrigerant
during routine system maintenance without recovery equipment D. Minimal releases
when connecting/disconnecting low-loss fittings
CORRECT ANSWER: C. Release of refrigerant during routine system maintenance
without recovery equipment
, Rationale: EPA Section 608 strictly prohibits venting of CFC and HCFC refrigerants
during maintenance, service, repair, or disposal. The only exceptions are: de minimis
releases during recovery attempts, normal operational releases from specific
equipment like purge units on low-pressure systems, and minimal releases when using
properly maintained low-loss fittings. Intentional venting during routine maintenance is
never permitted.
www.epa.gov
Question 11: 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 containing HCFC-22 with less than 200
pounds of refrigerant, EPA regulations require evacuation to 4 inches of Hg vacuum
when using recovery equipment certified after November 15, 1993. Equipment
manufactured before this date had less stringent requirements (0 inches Hg vacuum for
systems under 200 lbs).
www.epa.gov
Question 12: Which component in a refrigeration system converts high-pressure
liquid refrigerant to low-pressure vapor?
A. Condenser B. Compressor C. Expansion device D. Evaporator
CORRECT ANSWER: C. Expansion device
Rationale: The expansion device (such as a thermostatic expansion valve, capillary
tube, or fixed orifice) creates a pressure drop that causes high-pressure liquid
refrigerant to flash into a low-pressure liquid-vapor mixture. This pressure reduction
enables the refrigerant to absorb heat in the evaporator at the desired temperature.
www.epa.gov
Question 13: What color is typically used for the compound (low-side) gauge on a
refrigerant manifold gauge set?
A. Red B. Blue C. Yellow D. Green
CORRECT ANSWER: B. Blue
Rationale: Standard refrigeration manifold gauge sets use color coding: blue for the
compound gauge (measures low-side pressure and vacuum in inches Hg), red for the
high-pressure gauge (measures discharge pressure), and yellow for the service/charging
Questions and Answers Updated 2026 | Complete
EPA Section 608 Study Guide with Verified
Questions, Detailed Rationales, Refrigerant
Handling, Recovery & Recycling Procedures, HVAC
System Safety, Environmental Regulations, Leak
Detection, Certification Core, Type I, Type II, Type
III Exam Prep & Technician Compliance Training
Question 1: Which atmospheric layer contains the majority of Earth's protective
ozone that filters harmful ultraviolet radiation?
A. Troposphere B. Mesosphere C. Stratosphere D. Thermosphere
CORRECT ANSWER: C. Stratosphere
Rationale: The stratosphere, located approximately 6-30 miles above Earth's surface,
contains approximately 90% of atmospheric ozone. This ozone layer absorbs 97-99% of
the Sun's harmful ultraviolet (UV-B and UV-C) radiation, protecting life on Earth from
DNA damage, skin cancer, and other health effects.
www.epa.gov
Question 2: What is the primary mechanism by which chlorine from CFC
refrigerants destroys stratospheric ozone?
A. Chlorine directly bonds with ozone to form stable compounds B. Chlorine acts as a
catalyst, repeatedly breaking down ozone molecules without being consumed C.
Chlorine absorbs UV radiation that would otherwise create ozone D. Chlorine displaces
oxygen atoms in ozone molecules permanently
CORRECT ANSWER: B. Chlorine acts as a catalyst, repeatedly breaking down ozone
molecules without being consumed
Rationale: A single chlorine atom can destroy over 100,000 ozone molecules through a
catalytic cycle. Chlorine reacts with ozone (O₃) to form chlorine monoxide (ClO) and
oxygen (O₂). ClO then reacts with atomic oxygen to regenerate chlorine, allowing the
cycle to repeat. This catalytic nature makes chlorine extremely destructive to the ozone
layer.
www.epa.gov
Question 3: Which refrigerant classification contains chlorine, fluorine, and carbon
but NO hydrogen?
A. HFC (Hydrofluorocarbon) B. HCFC (Hydrochlorofluorocarbon) C. CFC
(Chlorofluorocarbon) D. PFC (Perfluorocarbon)
CORRECT ANSWER: C. CFC (Chlorofluorocarbon)
,Rationale: CFCs contain only chlorine, fluorine, and carbon atoms. The absence of
hydrogen makes CFCs extremely stable in the lower atmosphere, allowing them to
persist long enough to reach the stratosphere where UV radiation breaks them down,
releasing ozone-depleting chlorine. Examples include R-11, R-12, and R-113.
www.epa.gov
Question 4: Which of the following refrigerants is classified as an HCFC?
A. R-12 B. R-22 C. R-134a D. R-410A
CORRECT ANSWER: B. R-22
Rationale: R-22 (chlorodifluoromethane) is an HCFC because it contains hydrogen,
chlorine, fluorine, and carbon. HCFCs have lower ozone depletion potential (ODP) than
CFCs because the hydrogen atom makes them more reactive in the lower atmosphere,
reducing the amount that reaches the stratosphere. R-22 has an ODP of 0.055.
www.epa.gov
Question 5: What does ODP stand for in refrigerant environmental impact
assessment?
A. Ozone Depletion Potential B. Ozone Destruction Parameter C. Ozone Damage
Percentage D. Ozone Degradation Profile
CORRECT ANSWER: A. Ozone Depletion Potential
Rationale: Ozone Depletion Potential (ODP) is a relative measure comparing a
substance's ability to destroy stratospheric ozone compared to CFC-11, which is
assigned an ODP of 1.0. CFCs typically have ODPs of 0.6-1.0, HCFCs range from 0.01-
0.1, and HFCs have an ODP of zero because they contain no chlorine.
www.epa.gov
Question 6: Which international treaty established the framework for phasing out
ozone-depleting substances globally?
A. Kyoto Protocol B. Paris Agreement C. Montreal Protocol D. Clean Air Accord
CORRECT ANSWER: C. Montreal Protocol
Rationale: The Montreal Protocol on Substances that Deplete the Ozone Layer,
adopted in 1987, is an international environmental agreement that regulates the
production and consumption of ozone-depleting substances. It has been ratified by all
198 UN member states and is considered one of the most successful environmental
treaties ever implemented.
www.epa.gov
Question 7: Under Section 608 of the Clean Air Act, what is the maximum civil
penalty for knowingly venting prohibited refrigerants?
,A. $10,000 per day per violation B. $25,000 per day per violation C. $37,500 per day per
violation (as adjusted for inflation) D. $100,000 per day per violation
CORRECT ANSWER: C. $37,500 per day per violation (as adjusted for inflation)
Rationale: The EPA adjusts civil penalties for inflation periodically. As of recent
adjustments, the maximum civil penalty for violations of Section 608 refrigerant
management regulations, including illegal venting, is $37,500 per day per violation.
Criminal penalties may also apply for knowing violations.
www.epa.gov
Question 8: Which refrigerant type has ZERO ozone depletion potential?
A. CFC B. HCFC C. HFC D. All of the above
CORRECT ANSWER: C. HFC
Rationale: Hydrofluorocarbons (HFCs) contain hydrogen, fluorine, and carbon but no
chlorine or bromine. Since chlorine and bromine are the elements responsible for ozone
depletion, HFCs have an ODP of zero. However, many HFCs have high global warming
potential (GWP), leading to ongoing regulatory efforts to phase down their use.
www.epa.gov
Question 9: What is the primary health concern associated with increased
ultraviolet radiation reaching Earth's surface due to ozone depletion?
A. Respiratory illness B. Skin cancer and cataracts C. Cardiovascular disease D.
Neurological disorders
CORRECT ANSWER: B. Skin cancer and cataracts
Rationale: Increased UV-B radiation due to ozone depletion is directly linked to higher
rates of skin cancers (including melanoma), premature skin aging, and cataracts. UV
radiation also suppresses immune system function and can damage terrestrial and
aquatic ecosystems. Protecting the ozone layer is critical for public health.
www.epa.gov
Question 10: Which of the following is NOT a prohibited venting exception under
EPA Section 608 regulations?
A. De minimis releases during good-faith recovery efforts B. Normal operational
releases from mechanical purging on low-pressure chillers C. Release of refrigerant
during routine system maintenance without recovery equipment D. Minimal releases
when connecting/disconnecting low-loss fittings
CORRECT ANSWER: C. Release of refrigerant during routine system maintenance
without recovery equipment
, Rationale: EPA Section 608 strictly prohibits venting of CFC and HCFC refrigerants
during maintenance, service, repair, or disposal. The only exceptions are: de minimis
releases during recovery attempts, normal operational releases from specific
equipment like purge units on low-pressure systems, and minimal releases when using
properly maintained low-loss fittings. Intentional venting during routine maintenance is
never permitted.
www.epa.gov
Question 11: 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 containing HCFC-22 with less than 200
pounds of refrigerant, EPA regulations require evacuation to 4 inches of Hg vacuum
when using recovery equipment certified after November 15, 1993. Equipment
manufactured before this date had less stringent requirements (0 inches Hg vacuum for
systems under 200 lbs).
www.epa.gov
Question 12: Which component in a refrigeration system converts high-pressure
liquid refrigerant to low-pressure vapor?
A. Condenser B. Compressor C. Expansion device D. Evaporator
CORRECT ANSWER: C. Expansion device
Rationale: The expansion device (such as a thermostatic expansion valve, capillary
tube, or fixed orifice) creates a pressure drop that causes high-pressure liquid
refrigerant to flash into a low-pressure liquid-vapor mixture. This pressure reduction
enables the refrigerant to absorb heat in the evaporator at the desired temperature.
www.epa.gov
Question 13: What color is typically used for the compound (low-side) gauge on a
refrigerant manifold gauge set?
A. Red B. Blue C. Yellow D. Green
CORRECT ANSWER: B. Blue
Rationale: Standard refrigeration manifold gauge sets use color coding: blue for the
compound gauge (measures low-side pressure and vacuum in inches Hg), red for the
high-pressure gauge (measures discharge pressure), and yellow for the service/charging
