EPA 609 TECHNICIAN CERTIFICATION EXAM
COMPREHENSIVE PRACTICE EXAM
EDITION
Motor Vehicle Air Conditioning (MVAC) Servicing • Clean Air Act Section 609 • 50 Questions • 7 Sections • Answers
and Rationales Included
Candidate Name: ______________________________ Date: ____________ Score: ______ / 50
EXAM OVERVIEW & INSTRUCTIONS
Governing body U.S. Environmental Protection Agency – Clean Air Act, Section 609
Who must be certified Any person who repairs or services a motor vehicle air conditioning (MVAC) system for
consideration (payment or bartering)
Test format 50 multiple-choice questions, 4 options (A–D) each, one correct answer
Passing score Set by the testing provider – commonly about 70–75% (some providers require higher)
Certification validity Section 609 certification does not expire under current EPA policy
Required to Purchase CFC-12 or EPA-approved MVAC substitutes; servicing is restricted to certified
technicians
HOW TO USE THIS PRACTICE EXAM
• Answers and rationales are printed directly beneath each question for immediate study and self-grading.
• Sections mirror the official exam content areas; the total is exactly 50 questions (10 + 10 + 8 + 7 + 5 + 5 + 5).
• Time yourself: roughly 45–60 minutes represents a realistic certification-test pace.
• Mark your answer on paper before reading the rationale, then score yourself at the end.
• Study tip: any question you miss points to the knowledge area you should review before the real exam.
EXAM AT A GLANCE
Section Content Area Questions
1 Ozone Layer & Atmospheric Science – Depletion mechanisms, UV radiation, ODP, 10
phase-out
2 Refrigerant Types & Properties – CFC-12, HFC-134a, HFO-1234yf, GWP, A2L, PAG oil 10
3 The Three “R”s – Recovery, Recycling & Reclaim 8
4 Recovery Requirements & Equipment – Cylinders, manifold set, disposal, shipping 7
5 Leak Detection & Prevention – Electronic detectors, UV dye (SAE J2791), repair 5
6 EPA Regulations & Compliance – CAA Section 609, recordkeeping, penalties 5
7 Integrated Scenario-Based Questions – Multi-domain MVAC servicing scenarios 5
TOTAL 50
Practice material for study purposes only. This document is not an official EPA publication; check current regulations
and certification requirements at epa.gov.
EPA 609 Technician Certification Exam – Comprehensive Practice (2026/2027 Edition) Page 1 of 17
, Section 1: Ozone Layer & Atmospheric Science – Ozone Depletion, UV Radiation, ODP,
CFC/HCFC/HFC Phase-Out (10 questions)
Q1: The stratospheric ozone layer is essential to life on Earth primarily because it -
A. reflects most incoming solar radiation back into space
B. absorbs the majority of the Sun's harmful ultraviolet (UV) radiation before it reaches the Earth's
surface (the correct choice) [CORRECT]
C. acts as a greenhouse layer that traps heat and warms the planet's surface
D. produces the oxygen that living organisms breathe
Correct Answer: B
Rationale: Ozone's critical role is absorbing roughly 95% or more of the Sun's harmful UV-B and UV-C radiation. Reflection
(A) is albedo, warming (C) is the greenhouse effect, and oxygen production (D) is photosynthesis - not ozone's function.
Q2: The protective ozone layer that shields Earth from harmful UV radiation is located in the -
A. troposphere, immediately above the ground
B. mesosphere, above the stratosphere
C. ionosphere, where radio waves bounce
D. stratosphere, approximately 10 to 50 km (6-31 miles) above the Earth (the correct choice) [CORRECT]
Correct Answer: D
Rationale: The ozone layer sits in the stratosphere, well above the troposphere where weather occurs. Options A-C place the
layer at the wrong altitudes.
Q3: A key reason CFCs released at ground level eventually reach the stratosphere is that they -
A. are lighter than air and float upward in the same way helium does
B. are chemically stable in the lower atmosphere, so they are not broken down before they slowly mix
upward to the stratosphere (the correct choice) [CORRECT]
C. are absorbed by rainwater and carried upward inside storm clouds
D. are actually produced in the stratosphere by reactions between methane and chlorine
Correct Answer: B
Rationale: CFCs are extremely stable in the troposphere - there is no natural removal process - so they persist and slowly
diffuse into the stratosphere. They are heavier than air (not lighter), not transported by rain, and are man-made, not naturally
produced.
Q4: In the stratosphere, when a CFC molecule absorbs ultraviolet radiation, it -
A. breaks its carbon-chlorine bond and releases a chlorine atom, which then catalytically destroys ozone
(the correct choice) [CORRECT]
B. converts into water vapor, which washes ozone out of the sky
C. is converted into carbon dioxide and carbon monoxide
D. forms a harmless salt that falls to the ground
Correct Answer: A
Rationale: UV radiation splits the C-Cl bond, releasing free chlorine atoms that enter the catalytic ozone-destroying cycle. The
other options describe reactions that do not occur with CFCs in the stratosphere.
EPA 609 Technician Certification Exam – Comprehensive Practice (2026/2027 Edition) Page 2 of 17
, Q5: Scientists estimate that a single chlorine atom released in the stratosphere can destroy -
A. about 10 ozone molecules before it stops working
B. about 100 ozone molecules before it stops working
C. up to about 100,000 ozone molecules before it is deactivated or removed (the correct choice)
[CORRECT]
D. more than 5 million ozone molecules
Correct Answer: C
Rationale: Because chlorine acts as a catalyst - it is regenerated after each reaction - one atom can destroy up to roughly
100,000 molecules before it is converted into a reservoir compound and removed. Options A, B and D do not reflect the
accepted catalytic-cycle estimate.
Q6: Which statement about Ozone Depletion Potential (ODP) is correct?
A. CFC-11 has an ODP of 1.0 and serves as the reference standard against which other chemicals are
compared (the correct choice) [CORRECT]
B. R-134a has an ODP of 1.0
C. CFC-12 has an ODP of 0 because it is no longer produced
D. The higher a refrigerant's ODP, the less ozone it depletes
Correct Answer: A
Rationale: CFC-11 is the reference chemical with ODP = 1.0. R-134a has an ODP of 0 (no chlorine), CFC-12 has an ODP
near 1.0, and a higher ODP means GREATER ozone depletion.
Q7: Which of the following refrigerants has an Ozone Depletion Potential (ODP) of zero?
A. R-12 (CFC-12)
B. R-22 (HCFC-22)
C. R-134a (HFC-134a) (the correct choice) [CORRECT]
D. All chlorofluorocarbons
Correct Answer: C
Rationale: R-134a contains no chlorine or bromine, so its ODP is zero. CFCs (R-12) and HCFCs (R-22) contain chlorine and
have positive ODPs.
Q8: Under the Clean Air Act, the production and import of CFCs (including CFC-12) in the United States was
fully prohibited beginning -
A. December 31, 1987, when the Montreal Protocol was signed
B. November 15, 1995
C. January 1, 1996 (the correct choice) [CORRECT]
D. January 1, 2010
Correct Answer: C
Rationale: The U.S. accelerated phaseout ended CFC production and import on January 1, 1996. 1987 was the signing of the
Montreal Protocol, Nov 15 1995 was the date MVAC servicing rules took effect for R-134a and other substitutes, and 2010
relates to HCFC production caps.
Q9: Increased UV-B radiation reaching the Earth's surface is associated with all of the following EXCEPT -
A. skin cancer
B. cataracts and suppression of the immune system
C. damage to crops and marine phytoplankton
D. increased production of ozone in the stratosphere (the correct choice) [CORRECT]
Correct Answer: D
Rationale: UV-B is linked to skin cancer, cataracts, immune suppression and ecosystem damage. It does not increase
stratospheric ozone production; in fact, UV-B is one of the drivers of ozone photochemistry.
EPA 609 Technician Certification Exam – Comprehensive Practice (2026/2027 Edition) Page 3 of 17
COMPREHENSIVE PRACTICE EXAM
EDITION
Motor Vehicle Air Conditioning (MVAC) Servicing • Clean Air Act Section 609 • 50 Questions • 7 Sections • Answers
and Rationales Included
Candidate Name: ______________________________ Date: ____________ Score: ______ / 50
EXAM OVERVIEW & INSTRUCTIONS
Governing body U.S. Environmental Protection Agency – Clean Air Act, Section 609
Who must be certified Any person who repairs or services a motor vehicle air conditioning (MVAC) system for
consideration (payment or bartering)
Test format 50 multiple-choice questions, 4 options (A–D) each, one correct answer
Passing score Set by the testing provider – commonly about 70–75% (some providers require higher)
Certification validity Section 609 certification does not expire under current EPA policy
Required to Purchase CFC-12 or EPA-approved MVAC substitutes; servicing is restricted to certified
technicians
HOW TO USE THIS PRACTICE EXAM
• Answers and rationales are printed directly beneath each question for immediate study and self-grading.
• Sections mirror the official exam content areas; the total is exactly 50 questions (10 + 10 + 8 + 7 + 5 + 5 + 5).
• Time yourself: roughly 45–60 minutes represents a realistic certification-test pace.
• Mark your answer on paper before reading the rationale, then score yourself at the end.
• Study tip: any question you miss points to the knowledge area you should review before the real exam.
EXAM AT A GLANCE
Section Content Area Questions
1 Ozone Layer & Atmospheric Science – Depletion mechanisms, UV radiation, ODP, 10
phase-out
2 Refrigerant Types & Properties – CFC-12, HFC-134a, HFO-1234yf, GWP, A2L, PAG oil 10
3 The Three “R”s – Recovery, Recycling & Reclaim 8
4 Recovery Requirements & Equipment – Cylinders, manifold set, disposal, shipping 7
5 Leak Detection & Prevention – Electronic detectors, UV dye (SAE J2791), repair 5
6 EPA Regulations & Compliance – CAA Section 609, recordkeeping, penalties 5
7 Integrated Scenario-Based Questions – Multi-domain MVAC servicing scenarios 5
TOTAL 50
Practice material for study purposes only. This document is not an official EPA publication; check current regulations
and certification requirements at epa.gov.
EPA 609 Technician Certification Exam – Comprehensive Practice (2026/2027 Edition) Page 1 of 17
, Section 1: Ozone Layer & Atmospheric Science – Ozone Depletion, UV Radiation, ODP,
CFC/HCFC/HFC Phase-Out (10 questions)
Q1: The stratospheric ozone layer is essential to life on Earth primarily because it -
A. reflects most incoming solar radiation back into space
B. absorbs the majority of the Sun's harmful ultraviolet (UV) radiation before it reaches the Earth's
surface (the correct choice) [CORRECT]
C. acts as a greenhouse layer that traps heat and warms the planet's surface
D. produces the oxygen that living organisms breathe
Correct Answer: B
Rationale: Ozone's critical role is absorbing roughly 95% or more of the Sun's harmful UV-B and UV-C radiation. Reflection
(A) is albedo, warming (C) is the greenhouse effect, and oxygen production (D) is photosynthesis - not ozone's function.
Q2: The protective ozone layer that shields Earth from harmful UV radiation is located in the -
A. troposphere, immediately above the ground
B. mesosphere, above the stratosphere
C. ionosphere, where radio waves bounce
D. stratosphere, approximately 10 to 50 km (6-31 miles) above the Earth (the correct choice) [CORRECT]
Correct Answer: D
Rationale: The ozone layer sits in the stratosphere, well above the troposphere where weather occurs. Options A-C place the
layer at the wrong altitudes.
Q3: A key reason CFCs released at ground level eventually reach the stratosphere is that they -
A. are lighter than air and float upward in the same way helium does
B. are chemically stable in the lower atmosphere, so they are not broken down before they slowly mix
upward to the stratosphere (the correct choice) [CORRECT]
C. are absorbed by rainwater and carried upward inside storm clouds
D. are actually produced in the stratosphere by reactions between methane and chlorine
Correct Answer: B
Rationale: CFCs are extremely stable in the troposphere - there is no natural removal process - so they persist and slowly
diffuse into the stratosphere. They are heavier than air (not lighter), not transported by rain, and are man-made, not naturally
produced.
Q4: In the stratosphere, when a CFC molecule absorbs ultraviolet radiation, it -
A. breaks its carbon-chlorine bond and releases a chlorine atom, which then catalytically destroys ozone
(the correct choice) [CORRECT]
B. converts into water vapor, which washes ozone out of the sky
C. is converted into carbon dioxide and carbon monoxide
D. forms a harmless salt that falls to the ground
Correct Answer: A
Rationale: UV radiation splits the C-Cl bond, releasing free chlorine atoms that enter the catalytic ozone-destroying cycle. The
other options describe reactions that do not occur with CFCs in the stratosphere.
EPA 609 Technician Certification Exam – Comprehensive Practice (2026/2027 Edition) Page 2 of 17
, Q5: Scientists estimate that a single chlorine atom released in the stratosphere can destroy -
A. about 10 ozone molecules before it stops working
B. about 100 ozone molecules before it stops working
C. up to about 100,000 ozone molecules before it is deactivated or removed (the correct choice)
[CORRECT]
D. more than 5 million ozone molecules
Correct Answer: C
Rationale: Because chlorine acts as a catalyst - it is regenerated after each reaction - one atom can destroy up to roughly
100,000 molecules before it is converted into a reservoir compound and removed. Options A, B and D do not reflect the
accepted catalytic-cycle estimate.
Q6: Which statement about Ozone Depletion Potential (ODP) is correct?
A. CFC-11 has an ODP of 1.0 and serves as the reference standard against which other chemicals are
compared (the correct choice) [CORRECT]
B. R-134a has an ODP of 1.0
C. CFC-12 has an ODP of 0 because it is no longer produced
D. The higher a refrigerant's ODP, the less ozone it depletes
Correct Answer: A
Rationale: CFC-11 is the reference chemical with ODP = 1.0. R-134a has an ODP of 0 (no chlorine), CFC-12 has an ODP
near 1.0, and a higher ODP means GREATER ozone depletion.
Q7: Which of the following refrigerants has an Ozone Depletion Potential (ODP) of zero?
A. R-12 (CFC-12)
B. R-22 (HCFC-22)
C. R-134a (HFC-134a) (the correct choice) [CORRECT]
D. All chlorofluorocarbons
Correct Answer: C
Rationale: R-134a contains no chlorine or bromine, so its ODP is zero. CFCs (R-12) and HCFCs (R-22) contain chlorine and
have positive ODPs.
Q8: Under the Clean Air Act, the production and import of CFCs (including CFC-12) in the United States was
fully prohibited beginning -
A. December 31, 1987, when the Montreal Protocol was signed
B. November 15, 1995
C. January 1, 1996 (the correct choice) [CORRECT]
D. January 1, 2010
Correct Answer: C
Rationale: The U.S. accelerated phaseout ended CFC production and import on January 1, 1996. 1987 was the signing of the
Montreal Protocol, Nov 15 1995 was the date MVAC servicing rules took effect for R-134a and other substitutes, and 2010
relates to HCFC production caps.
Q9: Increased UV-B radiation reaching the Earth's surface is associated with all of the following EXCEPT -
A. skin cancer
B. cataracts and suppression of the immune system
C. damage to crops and marine phytoplankton
D. increased production of ozone in the stratosphere (the correct choice) [CORRECT]
Correct Answer: D
Rationale: UV-B is linked to skin cancer, cataracts, immune suppression and ecosystem damage. It does not increase
stratospheric ozone production; in fact, UV-B is one of the drivers of ozone photochemistry.
EPA 609 Technician Certification Exam – Comprehensive Practice (2026/2027 Edition) Page 3 of 17
