EPA 608 CERTIFICATION EXAM 2026/2027 QUESTIONS AND ANSWERS, Exams of
Nursing Comprehensive Assessment
2026-2027
100 Questions
100% VERIFIED
Introduction
This comprehensive assessment verifies the essential knowledge required for EPA Section 608
certification, the recognized credential for technicians who service refrigeration and air conditioning
equipment containing regulated refrigerants. The examination evaluates the candidate's mastery of
the core competencies that govern safe and environmentally responsible work, and it confirms
readiness to perform duties that are fundamental to protecting the stratospheric ozone layer and
mitigating climate change. The content is organized around the eight principal domains of the official
blueprint: Refrigerant Types and Properties, EPA Regulations and Clean Air Act, Recovery, Recycling,
and Reclaiming Procedures, Leak Detection and Repair, Safety and Handling of Refrigerants, System
Evacuation and Dehydration, EPA 608 Certification Types (Core, Type I, Type II, Type III, and
Universal), and Environmental Impact and Ozone Depletion.
Successful completion of this examination reflects the proficiency and professional judgment required
to handle refrigerants safely, prevent leaks, and execute compliant recovery, recycling, and reclaiming
operations that keep harmful emissions out of the atmosphere. It certifies that the technician can apply
the regulations of the Clean Air Act, use certified equipment, perform proper system evacuation and
dehydration, and manage the environmental impact of refrigerants through sound maintenance and
professional operations. Mastery of the domains examined here supports the competencies required
for certification across all equipment types and is a demonstrated measure of the knowledge needed to
perform effectively and responsibly in the field.
1. Which refrigerant is classified as a CFC and is a primary ozone-depleting substance targeted
by the Montreal Protocol?
A. R-407C
B. R-12, dichlorodifluoromethane
C. R-134a
D. R-410A
Rationale: R-12 is a chlorofluorocarbon whose chlorine atoms are released in the stratosphere and destroy
ozone. R-134a is an HFC, while R-410A and R-407C are blends of HFCs; none of these alternatives contain
chlorine.
2. An HFC refrigerant such as R-134a has an ozone depletion potential (ODP) of:
A. 1.0
B. 0.5
C. 0.9
D. Zero, because it contains no chlorine.
,Rationale: HFCs contain hydrogen, fluorine, and carbon but no chlorine or bromine, so they do not deplete the
ozone layer; their ODP is zero. An ODP of 0.5, 0.9, or 1.0 would indicate ozone-depleting chlorine or bromine
content.
3. The term 'azeotropic blend' in refrigeration describes a refrigerant mixture that:
A. Behaves as a single substance with a constant boiling point at a given pressure.
B. Boils at a wide range of temperatures
C. Separates into different components during evaporation
D. Requires a special system because it cannot be reused
Rationale: An azeotropic blend evaporates and condenses as if it were one pure refrigerant, maintaining a
constant temperature during phase change. Zeotropic blends instead exhibit temperature glide, and azeotropes
are fully recoverable.
4. When a zeotropic refrigerant blend such as R-407C changes phase, it typically experiences:
A. A loss of ozone depleting potential during phase change
B. An immediate chemical reaction on contact with lubricant
C. A constant boiling temperature with no variation
D. Temperature glide, with a range of boiling temperatures.
Rationale: Zeotropic blends do not evaporate at a single temperature; instead they exhibit temperature glide
across the evaporating and condensing range. The presence of glide means the blend does not have a single flat
phase-change temperature.
5. What is an azeotrope's defining property relevant to recovery?
A. The mixture must be vented because it cannot be reused
B. Only the vapor portion can be recovered
C. The mixture changes composition permanently during evaporation and splits
D. The mixture can be recovered, recycled, and reused as an azeotrope without changing
composition and without a separate purity test.
Rationale: Azeotropes keep a constant composition through vaporization and condensation, so recovered liquid
can be reused directly as the same azeotrope. Non-azeotropic blends, by contrast, must be tested for purity
before reuse.
6. R-410A is an example of a near-azeotropic blend that is commonly used as a service
replacement for which refrigerant?
A. R-22
B. R-12
C. R-502
D. R-11
Rationale: R-410A was developed as an HFC replacement for R-22 in residential and light commercial air
conditioning. It is not a substitute for R-12, R-502, or R-11, which each require their own replacement
refrigerants.
7. Which refrigerant is commonly used as a replacement for R-12 in automotive air
conditioning applications?
A. R-22
B. R-502
, C. R-134a
D. R-11
Rationale: R-134a is an HFC that replaced R-12 in motor vehicle air conditioning because it is non-ozone-
depleting and has similar operating characteristics. R-22, R-11, and R-502 are not automotive air conditioning
refrigerants.
8. A refrigerant compressor that returns liquid refrigerant to the compressor risks what
condition?
A. Reduced superheat with no mechanical injury
B. Improved lubrication of the moving parts
C. Liquid slugging, which can cause severe compressor damage.
D. A more efficient cooling cycle
Rationale: Incompressible liquid entering the compressor cylinder can cause catastrophic hydraulic damage to
valves and pistons, known as liquid slugging. It does not improve lubrication or efficiency and is not benign.
9. The term 'superheat' refers to the temperature difference between the:
A. Evaporating and condensing pressures
B. Liquid temperature and the ambient air temperature
C. Suction and discharge pressures
D. Refrigerant vapor temperature and its saturation temperature at the same pressure.
Rationale: Superheat measures how far the vapor temperature is heated above its saturation (boiling)
temperature at the given pressure, indicating the degree of vapor superheating. It is not a comparison with
ambient air or with system pressures.
10. Which statement about a refrigerant's global warming potential (GWP) is correct?
A. GWP is always zero for HFC refrigerants
B. A refrigerant with a high GWP contributes far more to greenhouse warming per kilogram
than carbon dioxide.
C. GWP is unrelated to a refrigerant's heat-trapping effect
D. GWP measures the ozone depletion caused by a refrigerant
Rationale: GWP compares a substance's heat-trapping effect over a set time relative to carbon dioxide; a high
GWP indicates a much stronger greenhouse effect per kilogram. GWP concerns warming, not ozone depletion,
and HFCs have significant GWP values.
11. Which refrigerant is a high-pressure blend most likely to be found in newer residential air
conditioning systems?
A. R-123
B. R-410A
C. R-113
D. R-11
Rationale: R-410A operates at significantly higher pressures than R-22 and is the standard blend in many newer
comfort cooling systems. R-11, R-123, and R-113 are low-pressure refrigerants used in large centrifugal systems,
not residential air conditioning.
12. When a refrigerant is in the two-phase region (a mixture of liquid and vapor), its
temperature is:
Nursing Comprehensive Assessment
2026-2027
100 Questions
100% VERIFIED
Introduction
This comprehensive assessment verifies the essential knowledge required for EPA Section 608
certification, the recognized credential for technicians who service refrigeration and air conditioning
equipment containing regulated refrigerants. The examination evaluates the candidate's mastery of
the core competencies that govern safe and environmentally responsible work, and it confirms
readiness to perform duties that are fundamental to protecting the stratospheric ozone layer and
mitigating climate change. The content is organized around the eight principal domains of the official
blueprint: Refrigerant Types and Properties, EPA Regulations and Clean Air Act, Recovery, Recycling,
and Reclaiming Procedures, Leak Detection and Repair, Safety and Handling of Refrigerants, System
Evacuation and Dehydration, EPA 608 Certification Types (Core, Type I, Type II, Type III, and
Universal), and Environmental Impact and Ozone Depletion.
Successful completion of this examination reflects the proficiency and professional judgment required
to handle refrigerants safely, prevent leaks, and execute compliant recovery, recycling, and reclaiming
operations that keep harmful emissions out of the atmosphere. It certifies that the technician can apply
the regulations of the Clean Air Act, use certified equipment, perform proper system evacuation and
dehydration, and manage the environmental impact of refrigerants through sound maintenance and
professional operations. Mastery of the domains examined here supports the competencies required
for certification across all equipment types and is a demonstrated measure of the knowledge needed to
perform effectively and responsibly in the field.
1. Which refrigerant is classified as a CFC and is a primary ozone-depleting substance targeted
by the Montreal Protocol?
A. R-407C
B. R-12, dichlorodifluoromethane
C. R-134a
D. R-410A
Rationale: R-12 is a chlorofluorocarbon whose chlorine atoms are released in the stratosphere and destroy
ozone. R-134a is an HFC, while R-410A and R-407C are blends of HFCs; none of these alternatives contain
chlorine.
2. An HFC refrigerant such as R-134a has an ozone depletion potential (ODP) of:
A. 1.0
B. 0.5
C. 0.9
D. Zero, because it contains no chlorine.
,Rationale: HFCs contain hydrogen, fluorine, and carbon but no chlorine or bromine, so they do not deplete the
ozone layer; their ODP is zero. An ODP of 0.5, 0.9, or 1.0 would indicate ozone-depleting chlorine or bromine
content.
3. The term 'azeotropic blend' in refrigeration describes a refrigerant mixture that:
A. Behaves as a single substance with a constant boiling point at a given pressure.
B. Boils at a wide range of temperatures
C. Separates into different components during evaporation
D. Requires a special system because it cannot be reused
Rationale: An azeotropic blend evaporates and condenses as if it were one pure refrigerant, maintaining a
constant temperature during phase change. Zeotropic blends instead exhibit temperature glide, and azeotropes
are fully recoverable.
4. When a zeotropic refrigerant blend such as R-407C changes phase, it typically experiences:
A. A loss of ozone depleting potential during phase change
B. An immediate chemical reaction on contact with lubricant
C. A constant boiling temperature with no variation
D. Temperature glide, with a range of boiling temperatures.
Rationale: Zeotropic blends do not evaporate at a single temperature; instead they exhibit temperature glide
across the evaporating and condensing range. The presence of glide means the blend does not have a single flat
phase-change temperature.
5. What is an azeotrope's defining property relevant to recovery?
A. The mixture must be vented because it cannot be reused
B. Only the vapor portion can be recovered
C. The mixture changes composition permanently during evaporation and splits
D. The mixture can be recovered, recycled, and reused as an azeotrope without changing
composition and without a separate purity test.
Rationale: Azeotropes keep a constant composition through vaporization and condensation, so recovered liquid
can be reused directly as the same azeotrope. Non-azeotropic blends, by contrast, must be tested for purity
before reuse.
6. R-410A is an example of a near-azeotropic blend that is commonly used as a service
replacement for which refrigerant?
A. R-22
B. R-12
C. R-502
D. R-11
Rationale: R-410A was developed as an HFC replacement for R-22 in residential and light commercial air
conditioning. It is not a substitute for R-12, R-502, or R-11, which each require their own replacement
refrigerants.
7. Which refrigerant is commonly used as a replacement for R-12 in automotive air
conditioning applications?
A. R-22
B. R-502
, C. R-134a
D. R-11
Rationale: R-134a is an HFC that replaced R-12 in motor vehicle air conditioning because it is non-ozone-
depleting and has similar operating characteristics. R-22, R-11, and R-502 are not automotive air conditioning
refrigerants.
8. A refrigerant compressor that returns liquid refrigerant to the compressor risks what
condition?
A. Reduced superheat with no mechanical injury
B. Improved lubrication of the moving parts
C. Liquid slugging, which can cause severe compressor damage.
D. A more efficient cooling cycle
Rationale: Incompressible liquid entering the compressor cylinder can cause catastrophic hydraulic damage to
valves and pistons, known as liquid slugging. It does not improve lubrication or efficiency and is not benign.
9. The term 'superheat' refers to the temperature difference between the:
A. Evaporating and condensing pressures
B. Liquid temperature and the ambient air temperature
C. Suction and discharge pressures
D. Refrigerant vapor temperature and its saturation temperature at the same pressure.
Rationale: Superheat measures how far the vapor temperature is heated above its saturation (boiling)
temperature at the given pressure, indicating the degree of vapor superheating. It is not a comparison with
ambient air or with system pressures.
10. Which statement about a refrigerant's global warming potential (GWP) is correct?
A. GWP is always zero for HFC refrigerants
B. A refrigerant with a high GWP contributes far more to greenhouse warming per kilogram
than carbon dioxide.
C. GWP is unrelated to a refrigerant's heat-trapping effect
D. GWP measures the ozone depletion caused by a refrigerant
Rationale: GWP compares a substance's heat-trapping effect over a set time relative to carbon dioxide; a high
GWP indicates a much stronger greenhouse effect per kilogram. GWP concerns warming, not ozone depletion,
and HFCs have significant GWP values.
11. Which refrigerant is a high-pressure blend most likely to be found in newer residential air
conditioning systems?
A. R-123
B. R-410A
C. R-113
D. R-11
Rationale: R-410A operates at significantly higher pressures than R-22 and is the standard blend in many newer
comfort cooling systems. R-11, R-123, and R-113 are low-pressure refrigerants used in large centrifugal systems,
not residential air conditioning.
12. When a refrigerant is in the two-phase region (a mixture of liquid and vapor), its
temperature is:
