EPA 608 Universal Certification |
Environmental Protection Agency | Academic
Year 2026/2027
section A: Ozone Depletion and Global Warming
1. Which element in a refrigerant molecule is primarily responsible for
stratospheric ozone depletion?
A) Fluorine
B) Chlorine
C) Carbon
D) Hydrogen
Correct Answer: B) Chlorine
Rationale: Chlorine is the element in CFCs and HCFCs that catalytically
destroys ozone molecules in the stratosphere. One chlorine atom can destroy up
to 100,000 ozone molecules before it is removed from the stratosphere. Fluorine
does not directly destroy ozone; it is the chlorine and bromine atoms that cause
ozone depletion. This is a foundational Core concept that appears on every
version of the EPA 608 exam.
2. Which of the following refrigerants has the highest Ozone Depletion Potential
(ODP)?
A) R-134a
B) R-410A
C) R-12
D) R-22
Correct Answer: C) R-12
, Rationale: R-12 is a chlorofluorocarbon (CFC) with an ODP of 1.0, the
highest classification. R-22 is an HCFC with an ODP of approximately 0.055. R-
134a and R-410A are HFCs with zero ODP. CFCs contain the most chlorine atoms
per molecule and are the most destructive to stratospheric ozone.
3. What is the primary difference between Ozone Depletion Potential (ODP) and
Global Warming Potential (GWP)?
A) ODP measures ozone destruction; GWP measures heat-trapping ability
B) ODP measures heat-trapping ability; GWP measures ozone destruction
C) Both measure ozone destruction
D) Both measure heat-trapping ability
Correct Answer: A) ODP measures ozone destruction; GWP measures
heat-trapping ability
Rationale: ODP quantifies a substance's ability to destroy stratospheric
ozone relative to R-11 (ODP = 1.0). GWP quantifies how much heat a greenhouse
gas traps in the atmosphere relative to CO₂ (GWP = 1.0 over 100 years). A
refrigerant can have zero ODP but high GWP (e.g., R-410A has ODP of 0 but GWP
of approximately 2,088). Understanding this distinction is critical for the 2026–
2027 exam, which emphasizes the AIM Act's GWP-based regulations.
4. Which type of refrigerant has zero Ozone Depletion Potential but may have
significant Global Warming Potential?
A) CFCs
B) HCFCs
C) HFCs
D) Halons
Correct Answer: C) HFCs
Rationale: Hydrofluorocarbons (HFCs) contain no chlorine or bromine and
therefore have zero ODP. However, many HFCs have high GWP values. For
,example, R-134a has a GWP of 1,430 and R-404A has a GWP of 3,922. The AIM
Act specifically targets HFCs for phasedown based on their GWP.
5. The stratospheric ozone layer protects life on Earth primarily by absorbing
which type of radiation?
A) Infrared radiation
B) Ultraviolet-B radiation
C) Microwave radiation
D) Gamma radiation
Correct Answer: B) Ultraviolet-B radiation
Rationale: The ozone layer absorbs most of the sun's ultraviolet-B (UV-B)
radiation, which is harmful to humans (causing skin cancer, cataracts, and
immune suppression) and ecosystems. Without the ozone layer, life on Earth's
surface would be unsustainable. This is a Core science concept that every
technician must understand.
6. What is the atmospheric lifetime of a chlorine atom in the stratosphere,
allowing it to destroy ozone repeatedly?
A) Several days
B) Several months
C) Several years
D) Over 100 years
Correct Answer: D) Over 100 years
Rationale: Once chlorine reaches the stratosphere, it can remain active for
over 100 years, catalytically destroying ozone molecules in a cycle that repeats
tens of thousands of times. This is why CFCs, despite being phased out, continue
to affect the ozone layer for generations.
, 7. Which international agreement established the framework for phasing out
ozone-depleting substances?
A) The Kyoto Protocol
B) The Montreal Protocol
C) The Paris Agreement
D) The Vienna Convention
Correct Answer: B) The Montreal Protocol
Rationale: The Montreal Protocol on Substances that Deplete the Ozone
Layer, adopted in 1987, is the international treaty that established binding phase-
out schedules for CFCs, HCFCs, halons, and other ozone-depleting substances. It is
widely considered the most successful environmental treaty in history. The
Vienna Convention (1985) was the framework agreement; the Montreal Protocol
provided the specific obligations.
8. What is the GWP of carbon dioxide (CO₂), which serves as the reference gas for
Global Warming Potential measurements?
A) 0
B) 1
C) 100
D) 1,000
Correct Answer: B) 1
Rationale: By definition, CO₂ has a GWP of 1. All other greenhouse gases
are measured relative to CO₂ over a specified time horizon (typically 100 years).
For example, R-410A has a GWP of approximately 2,088, meaning it traps 2,088
times more heat than CO₂ over 100 years.
9. Which refrigerant is classified as an HCFC?
A) R-12
B) R-22
Environmental Protection Agency | Academic
Year 2026/2027
section A: Ozone Depletion and Global Warming
1. Which element in a refrigerant molecule is primarily responsible for
stratospheric ozone depletion?
A) Fluorine
B) Chlorine
C) Carbon
D) Hydrogen
Correct Answer: B) Chlorine
Rationale: Chlorine is the element in CFCs and HCFCs that catalytically
destroys ozone molecules in the stratosphere. One chlorine atom can destroy up
to 100,000 ozone molecules before it is removed from the stratosphere. Fluorine
does not directly destroy ozone; it is the chlorine and bromine atoms that cause
ozone depletion. This is a foundational Core concept that appears on every
version of the EPA 608 exam.
2. Which of the following refrigerants has the highest Ozone Depletion Potential
(ODP)?
A) R-134a
B) R-410A
C) R-12
D) R-22
Correct Answer: C) R-12
, Rationale: R-12 is a chlorofluorocarbon (CFC) with an ODP of 1.0, the
highest classification. R-22 is an HCFC with an ODP of approximately 0.055. R-
134a and R-410A are HFCs with zero ODP. CFCs contain the most chlorine atoms
per molecule and are the most destructive to stratospheric ozone.
3. What is the primary difference between Ozone Depletion Potential (ODP) and
Global Warming Potential (GWP)?
A) ODP measures ozone destruction; GWP measures heat-trapping ability
B) ODP measures heat-trapping ability; GWP measures ozone destruction
C) Both measure ozone destruction
D) Both measure heat-trapping ability
Correct Answer: A) ODP measures ozone destruction; GWP measures
heat-trapping ability
Rationale: ODP quantifies a substance's ability to destroy stratospheric
ozone relative to R-11 (ODP = 1.0). GWP quantifies how much heat a greenhouse
gas traps in the atmosphere relative to CO₂ (GWP = 1.0 over 100 years). A
refrigerant can have zero ODP but high GWP (e.g., R-410A has ODP of 0 but GWP
of approximately 2,088). Understanding this distinction is critical for the 2026–
2027 exam, which emphasizes the AIM Act's GWP-based regulations.
4. Which type of refrigerant has zero Ozone Depletion Potential but may have
significant Global Warming Potential?
A) CFCs
B) HCFCs
C) HFCs
D) Halons
Correct Answer: C) HFCs
Rationale: Hydrofluorocarbons (HFCs) contain no chlorine or bromine and
therefore have zero ODP. However, many HFCs have high GWP values. For
,example, R-134a has a GWP of 1,430 and R-404A has a GWP of 3,922. The AIM
Act specifically targets HFCs for phasedown based on their GWP.
5. The stratospheric ozone layer protects life on Earth primarily by absorbing
which type of radiation?
A) Infrared radiation
B) Ultraviolet-B radiation
C) Microwave radiation
D) Gamma radiation
Correct Answer: B) Ultraviolet-B radiation
Rationale: The ozone layer absorbs most of the sun's ultraviolet-B (UV-B)
radiation, which is harmful to humans (causing skin cancer, cataracts, and
immune suppression) and ecosystems. Without the ozone layer, life on Earth's
surface would be unsustainable. This is a Core science concept that every
technician must understand.
6. What is the atmospheric lifetime of a chlorine atom in the stratosphere,
allowing it to destroy ozone repeatedly?
A) Several days
B) Several months
C) Several years
D) Over 100 years
Correct Answer: D) Over 100 years
Rationale: Once chlorine reaches the stratosphere, it can remain active for
over 100 years, catalytically destroying ozone molecules in a cycle that repeats
tens of thousands of times. This is why CFCs, despite being phased out, continue
to affect the ozone layer for generations.
, 7. Which international agreement established the framework for phasing out
ozone-depleting substances?
A) The Kyoto Protocol
B) The Montreal Protocol
C) The Paris Agreement
D) The Vienna Convention
Correct Answer: B) The Montreal Protocol
Rationale: The Montreal Protocol on Substances that Deplete the Ozone
Layer, adopted in 1987, is the international treaty that established binding phase-
out schedules for CFCs, HCFCs, halons, and other ozone-depleting substances. It is
widely considered the most successful environmental treaty in history. The
Vienna Convention (1985) was the framework agreement; the Montreal Protocol
provided the specific obligations.
8. What is the GWP of carbon dioxide (CO₂), which serves as the reference gas for
Global Warming Potential measurements?
A) 0
B) 1
C) 100
D) 1,000
Correct Answer: B) 1
Rationale: By definition, CO₂ has a GWP of 1. All other greenhouse gases
are measured relative to CO₂ over a specified time horizon (typically 100 years).
For example, R-410A has a GWP of approximately 2,088, meaning it traps 2,088
times more heat than CO₂ over 100 years.
9. Which refrigerant is classified as an HCFC?
A) R-12
B) R-22
