EPA 609 (Section 609) Certification Study Guide
Syllabus: 2026/2027 Updated Version
Note: Answers are formatted as requested.
Section 1: The Clean Air Act and the Ozone Layer
1. What specific section of the Clean Air Act regulates the servicing of Motor
Vehicle Air Conditioning (MVACs)?
ANSWER ✓ Section 609
2. Which agency is responsible for enforcing the regulations of the Clean Air Act
regarding MVACs?
ANSWER ✓ The Environmental Protection Agency (EPA)
3. What is the primary purpose of Title VI of the Clean Air Act?
ANSWER ✓ To protect the stratospheric ozone layer by phasing out the production of
ozone-depleting substances (ODS).
4. Which refrigerant, commonly used in older vehicles, is considered a Class I
Ozone Depleting Substance?
ANSWER ✓ CFC-12 (also known as R-12 or Freon)
5. What is the "Ozone Depletion Potential" (ODP) of CFC-12?
ANSWER ✓ 1.0 (It is the baseline against which other substances are measured).
6. What is the Ozone Depletion Potential of HFC-134a?
ANSWER ✓ 0 (Zero)
7. Why was HFC-134a originally introduced as a replacement for CFC-12?
ANSWER ✓ It has zero Ozone Depletion Potential (ODP).
8. Despite having zero ODP, why is HFC-134a being phased down in newer
vehicles?
, ANSWER ✓ It has a high Global Warming Potential (GWP).
9. What is the Global Warming Potential (GWP) of HFC-134a?
ANSWER ✓ 1,430 (It is 1,430 times more potent at trapping heat than CO2).
10. What is the mandated refrigerant for virtually all new light-duty vehicles
manufactured in the U.S. starting with model year 2021/2024?
ANSWER ✓ HFO-1234yf
11. What is the GWP of HFO-1234yf?
ANSWER ✓ 4 (Less than 1, significantly lower than HFC-134a).
12. What chemical property makes HFO-1234yf mildly flammable (ASHRAE A2L
classification)?
ANSWER ✓ It has a low flammability limit and low burning velocity.
Section 2: Refrigerant Handling and Safety
13. If you spill liquid HFO-1234yf on your skin, what is the immediate first aid
procedure?
ANSWER ✓ Flush the affected area with cool water for 15 minutes and remove any
contaminated clothing.
14. Why should you never use compressed air to leak test or pressure test an
MVAC system containing HFO-1234yf?
ANSWER ✓ Compressed air mixed with HFO-1234yf can create a flammable mixture.
15. Where should you store refrigerant cylinders?
ANSWER ✓ In a cool, dry, well-ventilated area, away from direct sunlight and ignition
sources.
16. What color code is typically associated with recovery cylinders for HFC-134a?
ANSWER ✓ Yellow or White with a yellow top (Note: Industry standards vary, but always
rely on the label, not color).
Syllabus: 2026/2027 Updated Version
Note: Answers are formatted as requested.
Section 1: The Clean Air Act and the Ozone Layer
1. What specific section of the Clean Air Act regulates the servicing of Motor
Vehicle Air Conditioning (MVACs)?
ANSWER ✓ Section 609
2. Which agency is responsible for enforcing the regulations of the Clean Air Act
regarding MVACs?
ANSWER ✓ The Environmental Protection Agency (EPA)
3. What is the primary purpose of Title VI of the Clean Air Act?
ANSWER ✓ To protect the stratospheric ozone layer by phasing out the production of
ozone-depleting substances (ODS).
4. Which refrigerant, commonly used in older vehicles, is considered a Class I
Ozone Depleting Substance?
ANSWER ✓ CFC-12 (also known as R-12 or Freon)
5. What is the "Ozone Depletion Potential" (ODP) of CFC-12?
ANSWER ✓ 1.0 (It is the baseline against which other substances are measured).
6. What is the Ozone Depletion Potential of HFC-134a?
ANSWER ✓ 0 (Zero)
7. Why was HFC-134a originally introduced as a replacement for CFC-12?
ANSWER ✓ It has zero Ozone Depletion Potential (ODP).
8. Despite having zero ODP, why is HFC-134a being phased down in newer
vehicles?
, ANSWER ✓ It has a high Global Warming Potential (GWP).
9. What is the Global Warming Potential (GWP) of HFC-134a?
ANSWER ✓ 1,430 (It is 1,430 times more potent at trapping heat than CO2).
10. What is the mandated refrigerant for virtually all new light-duty vehicles
manufactured in the U.S. starting with model year 2021/2024?
ANSWER ✓ HFO-1234yf
11. What is the GWP of HFO-1234yf?
ANSWER ✓ 4 (Less than 1, significantly lower than HFC-134a).
12. What chemical property makes HFO-1234yf mildly flammable (ASHRAE A2L
classification)?
ANSWER ✓ It has a low flammability limit and low burning velocity.
Section 2: Refrigerant Handling and Safety
13. If you spill liquid HFO-1234yf on your skin, what is the immediate first aid
procedure?
ANSWER ✓ Flush the affected area with cool water for 15 minutes and remove any
contaminated clothing.
14. Why should you never use compressed air to leak test or pressure test an
MVAC system containing HFO-1234yf?
ANSWER ✓ Compressed air mixed with HFO-1234yf can create a flammable mixture.
15. Where should you store refrigerant cylinders?
ANSWER ✓ In a cool, dry, well-ventilated area, away from direct sunlight and ignition
sources.
16. What color code is typically associated with recovery cylinders for HFC-134a?
ANSWER ✓ Yellow or White with a yellow top (Note: Industry standards vary, but always
rely on the label, not color).
