EPA Section 608 Teaching Material and Universal Certification Preparation

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.1-2

Correct answer: A. In the stratosphere

Most protective atmospheric ozone is in the stratosphere, where a broad ozone-rich region absorbs harmful ultraviolet radiation.

B is incorrect: Ground-level ozone is a harmful pollutant and is not the protective ozone layer.
C is incorrect: The protective ozone layer is centered in the stratosphere, not confined to the lower troposphere.
D is incorrect: The ozone layer is global; Antarctica experiences severe seasonal depletion but does not contain the only protective ozone.

Topic: Ozone location

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.1-3

Correct answer: C. Both are $O_{3}$ , but their effects differ because they occur in different atmospheric locations.

Ground-level ozone and stratospheric ozone are the same chemical species, $O_{3}$ , but location determines whether ozone is harmful pollution or protective atmospheric ozone.

A is incorrect: Both ground-level and stratospheric ozone are the same molecule, $O_{3}$ .
B is incorrect: This reverses the roles: ground-level ozone is a harmful pollutant, while stratospheric ozone provides UV protection.
D is incorrect: Ground-level photochemical ozone pollution does not become the stratospheric ozone layer.

Topic: Ground-level versus stratospheric ozone

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.1-4

Correct answer: B. UVB

Stratospheric ozone depletion most directly increases UVB reaching Earth’s surface because ozone absorbs a large fraction of UVB.

A is incorrect: UVA is only weakly absorbed by ozone, so ozone depletion is most directly associated with increased UVB rather than UVA.
C is incorrect: UVC is normally absorbed before reaching Earth’s surface, so it is not the band that increases at the surface in the ordinary ozone-depletion comparison.
D is incorrect: Infrared radiation is not an ultraviolet band and is not the primary radiation controlled by stratospheric ozone.

Topic: Ultraviolet radiation

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.1-5

Correct answer: B. It is absorbed by atmospheric oxygen and ozone before normally reaching the Earth’s surface.

UVC is absorbed very strongly by atmospheric oxygen and ozone and therefore does not normally reach Earth’s surface in significant amounts.

A is incorrect: UVC is strongly absorbed by atmospheric oxygen and ozone.
C is incorrect: UVC is ultraviolet radiation, not the main component of visible light.
D is incorrect: UVC originates from solar and other sources; it is not produced only by ground-level ozone.

Topic: Ultraviolet radiation

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.1-6

Correct answer: C. Increased risk of skin cancer and cataracts

Greater UVB exposure is associated with increased risks such as skin cancer and cataracts, among other health effects.

A is incorrect: Greater UVB exposure increases, rather than reduces, cataract risk.
B is incorrect: Greater UVB exposure increases skin-cancer risk rather than eliminating it.
D is incorrect: Excess UV exposure can suppress aspects of immune function; it is not a universal health improvement.

Topic: Health effects of ozone depletion

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.1-7

Correct answer: C. Damage to sensitive plants and aquatic food-web organisms

Increased UVB can damage sensitive plants, phytoplankton and other aquatic organisms, and can contribute to material degradation.

A is incorrect: Increased UVB can damage phytoplankton and disrupt aquatic food webs rather than protect them.
B is incorrect: Greater UV exposure can accelerate degradation of some polymers and materials rather than reduce it.
D is incorrect: Ozone depletion can increase UV-related material degradation rather than eliminate it.

Topic: Environmental effects of ozone depletion

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.1-8

Correct answer: B. A broad region of the stratosphere containing most atmospheric ozone

The ozone layer is not a solid shell; it is a broad region of the stratosphere containing most of the atmosphere’s ozone.

A is incorrect: The ozone layer is a diffuse ozone-rich region, not a solid shell of pure ozone.
C is incorrect: Ground-level smog is a tropospheric pollution problem and is not the stratospheric ozone layer.
D is incorrect: The Antarctic ozone hole is severe seasonal depletion, not a permanent empty opening in the atmosphere.

Topic: Ozone-layer structure

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Part B - Section 2.2 Concept-Check Answers

Source section: Section 2.2 - Ozone Depletion Process

Answer key: B C A B B B A C

Question 2.2-1

Correct answer: B. They are generally stable in the troposphere and can be transported by atmospheric circulation.

Many CFCs are chemically stable in the troposphere, so they can persist long enough to be transported by atmospheric circulation into the stratosphere.

A is incorrect: Long-lived CFCs are not rapidly removed by rain; their stability is what allows transport toward the stratosphere.
C is incorrect: ODS molecules are not drawn to the ozone layer by electrical attraction; atmospheric circulation transports them.
D is incorrect: CFCs are comparatively stable in the troposphere and are not immediately destroyed by ground-level ozone.

Topic: Transport of ozone-depleting substances

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.2-2

Correct answer: C. It breaks ODS molecules and releases reactive chlorine or bromine.

In the stratosphere, energetic ultraviolet radiation can break chlorine- or bromine-containing ODS molecules and release reactive halogen species.

A is incorrect: Ultraviolet radiation releases chlorine from chlorine-containing ODS molecules; ordinary oxygen contains no chlorine.
B is incorrect: Ground-level ozone does not convert into CFC refrigerant; the ozone-depletion mechanism occurs after ODS transport and photolysis.
D is incorrect: Reactive chlorine is cycled among stratospheric species and can be regenerated; UV photolysis does not permanently remove all chlorine.

Topic: Photolysis of ozone-depleting substances

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.2-3

Correct answer: A. Chlorine monoxide radical and molecular oxygen

In the simplified chlorine cycle, a chlorine radical reacts with ozone to form chlorine monoxide radical, $Cl O^{∙}$ , and molecular oxygen, $O_{2}$ .

B is incorrect: That is not the first reaction in the simplified catalytic cycle used here; $C l^{∙} + O_{3}$ produces $Cl O^{∙} + O_{2}$ .
C is incorrect: The catalytic ozone-destruction cycle does not regenerate a CFC molecule from ozone.
D is incorrect: Bromine chemistry is important, but the question asks for the chlorine cycle, whose product is chlorine monoxide radical.

Topic: Chlorine catalytic cycle

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.2-4

Correct answer: B. It is regenerated and can participate in repeated reaction cycles.

Chlorine acts catalytically because it is regenerated during the reaction sequence and can participate in additional ozone-destruction cycles.

A is incorrect: Chlorine is regenerated as a reactive chlorine species; it is not permanently converted into ozone.
C is incorrect: Chlorine is a catalyst in the reaction cycle; it is not the source of all stratospheric oxygen atoms.
D is incorrect: Ultraviolet radiation reaches ODS molecules and drives their photolysis; chlorine does not shield them from UV.

Topic: Catalytic ozone destruction

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.2-5

Correct answer: B. Ozone and atomic oxygen are converted into molecular oxygen.

The simplified two-step cycle has the net effect of converting ozone and atomic oxygen into molecular oxygen while regenerating chlorine.

A is incorrect: The cycle destroys ozone; it does not produce two ozone molecules.
C is incorrect: The key catalytic feature is that chlorine is regenerated rather than permanently consumed.
D is incorrect: The simplified catalytic cycle regenerates chlorine, not the original CFC molecule.

Topic: Net ozone-destruction reaction

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.2-6

Correct answer: B. HCFCs generally react more readily in the troposphere, so less chlorine reaches the stratosphere, but their ODP is not zero.

HCFCs contain chlorine and have nonzero ODP, but their greater reactivity in the lower atmosphere generally reduces the fraction that survives to reach the stratosphere compared with CFCs.

A is incorrect: HCFCs do contain chlorine; the ‘C’ before F in HCFC indicates chlorine is part of the molecule.
C is incorrect: HCFCs generally have lower ODP than CFCs because more are removed in the lower atmosphere before reaching the stratosphere.
D is incorrect: HCFCs that reach the stratosphere can undergo UV photolysis and release chlorine.

Topic: CFC versus HCFC ozone impact

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.2-7

Correct answer: A. Halons

Halons are an important anthropogenic source of stratospheric bromine, which can participate efficiently in catalytic ozone destruction.

B is incorrect: This substance is not an important anthropogenic bromine source; halons are the relevant bromine-containing ODS in this question.
C is incorrect: This substance is not an important anthropogenic bromine source; halons are the relevant bromine-containing ODS in this question.
D is incorrect: Carbon dioxide is the GWP reference gas, not the ODP reference substance.

Topic: Bromine-containing ozone-depleting substances

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.2-8

Correct answer: C. Their particle surfaces help convert chlorine reservoir species into forms that can become highly reactive.

Polar stratospheric cloud surfaces promote chemical conversion of relatively inactive chlorine reservoir species into forms that can become highly reactive when sunlight returns.

A is incorrect: Polar stratospheric clouds do not manufacture CFCs; their surfaces facilitate activation of chlorine reservoir species.
B is incorrect: Polar stratospheric clouds do not permanently block all sunlight; sunlight returning in spring helps drive rapid ozone-loss chemistry.
D is incorrect: Polar stratospheric clouds alter chlorine chemistry; they do not remove every chlorine-containing compound from the atmosphere.

Topic: Polar ozone chemistry

EPA 608 section: Core

Difficulty: Challenging

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Part C - Section 2.3 Concept-Check Answers

Source section: Section 2.3 - Refrigerant Families ODP and GWP

Answer key: A B C B B C B B

Question 2.3-1

Correct answer: A. Hydrogen, carbon, chlorine, and fluorine

HCFC means hydrochlorofluorocarbon; the family contains hydrogen, carbon, chlorine, and fluorine.

B is incorrect: That composition describes an HFC, not an HCFC, because it omits chlorine.
C is incorrect: That does not describe an HCFC; HCFCs contain hydrogen, carbon, chlorine, and fluorine.
D is incorrect: That composition corresponds neither to an HCFC nor to the halocarbon family described here.

Topic: HCFC composition

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.3-2

Correct answer: B. CFC-11

Ozone-depletion potential is expressed relative to CFC-11, which is assigned an ODP of 1.0.

A is incorrect: Carbon dioxide is the GWP reference gas, not the ODP reference substance.
C is incorrect: HFC-134a is an HFC with zero ODP; it is not the ODP reference substance.
D is incorrect: Ammonia is not the ODP reference substance.

Topic: Ozone-depletion potential

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.3-3

Correct answer: C. Carbon dioxide

Global-warming potential uses carbon dioxide as the reference gas with a GWP of 1.

A is incorrect: CFC-12 is not the GWP reference gas.
B is incorrect: HCFC-22 is not the GWP reference gas.
D is incorrect: Water is not the reference gas used for GWP in this module.

Topic: Global-warming potential

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.3-4

Correct answer: B. They have zero ODP, but many have significant GWP.

HFCs contain no chlorine, so their ODP is zero, but many HFCs can still have substantial global-warming potential.

A is incorrect: HFCs contain no chlorine and therefore have zero ODP.
C is incorrect: That describes hydrocarbons, not HFCs; HFCs also contain fluorine.
D is incorrect: Refrigerant safety and acceptability depend on the specific substance and end use; HFC status does not guarantee universal acceptability.

Topic: HFC environmental effects

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.3-5

Correct answer: B. Their carbon-carbon double bond generally increases lower-atmosphere reactivity and shortens atmospheric lifetime.

The carbon-carbon double bond in common HFOs increases their reactivity in the lower atmosphere, shortening atmospheric lifetime and generally lowering GWP relative to many saturated HFCs.

A is incorrect: HFOs do not obtain low GWP by using chlorine; common HFOs contain no chlorine.
C is incorrect: HFOs are fluorinated organic molecules and are not carbon dioxide.
D is incorrect: HFOs can absorb infrared radiation; low GWP mainly reflects their short atmospheric lifetime, not zero infrared absorption.

Topic: HFO atmospheric behavior

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.3-6

Correct answer: C. R-744 — carbon dioxide

R-744 is the ASHRAE refrigerant designation for carbon dioxide.

A is incorrect: R-290 is propane, a hydrocarbon, not ammonia.
B is incorrect: R-717 is ammonia, not carbon dioxide.
D is incorrect: R-718 is water, not propane.

Topic: Refrigerant identities

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.3-7

Correct answer: B. A refrigerant may have zero ODP but still have high GWP, safety hazards, or indirect energy impacts.

Zero ODP addresses only stratospheric ozone depletion; a refrigerant may still have climate impacts, safety hazards, energy-use implications, or application restrictions.

A is incorrect: Zero ODP does not make a substitute automatically exempt from the venting prohibition.
C is incorrect: ODP and GWP measure different environmental effects: ozone depletion and climate forcing.
D is incorrect: Zero ODP does not establish equipment compatibility, safety, SNAP acceptability, or retrofit approval.

Topic: ODP versus total environmental effect

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DIST

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.3-8

Correct answer: B. GWP can depend on the time horizon, scientific assessment, and regulatory reference adopted.

Published GWP values can differ because the time horizon, scientific assessment, and regulatory reference adopted may differ among sources.

A is incorrect: GWP is explicitly relative to a reference gas, carbon dioxide.
C is incorrect: The refrigerant composition does not change because a table is printed; differences usually arise from assessment methodology and time horizon.
D is incorrect: ODP and GWP are separate metrics and are not added together to create a newer GWP.

Topic: GWP source basis

EPA 608 section: Core

Difficulty: Standard

Suggested error code: SRC

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Part D - Section 2.4 Concept-Check Answers

Source section: Section 2.4 - Clean Air Act and Montreal Protocol

Answer key: B C A D B C A D

Question 2.4-1

Correct answer: B. It is an international agreement controlling the production and consumption of ozone-depleting substances.

The Montreal Protocol is an international agreement that controls production and consumption of ozone-depleting substances through agreed phaseout schedules.

A is incorrect: The Montreal Protocol is an international treaty framework, not a U.S.-only technician-certification regulation.
C is incorrect: An ASHRAE safety standard is an industry standard, not the Montreal Protocol.
D is incorrect: State contractor licensing is separate from the international Montreal Protocol.

Topic: Montreal Protocol

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Treaty source: UNEP — Montreal Protocol

Question 2.4-2

Correct answer: C. Section 608

Clean Air Act Section 608 establishes the National Recycling and Emission Reduction Program for stationary refrigeration and air-conditioning refrigerant management.

A is incorrect: Section 602 addresses listing/classification of ozone-depleting substances rather than the Section 608 refrigerant-management program.
B is incorrect: Section 604 addresses Class I phaseout, not the National Recycling and Emission Reduction Program.
D is incorrect: Section 612 is associated with SNAP substitute evaluation, not the Section 608 service program.

Topic: Clean Air Act Section 608

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Ozone Protection under Title VI of the Clean Air Act

Question 2.4-3

Correct answer: A. January 1, 1996

January 1, 1996 is the principal U.S. CFC/Class I production-and-import phaseout date commonly emphasized in Section 608 preparation, subject to authorized exceptions.

B is incorrect: 2003 is associated with an HCFC phaseout step, not the principal CFC production/import phaseout date.
C is incorrect: 2010 is an HCFC restriction milestone, not the principal CFC phaseout date.
D is incorrect: 2020 is the major HCFC-22/HCFC-142b production/import milestone, not the principal CFC phaseout date.

Topic: CFC phaseout timeline

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Phaseout of Class I Ozone-Depleting Substances

Question 2.4-4

Correct answer: D. U.S. production and import of HCFC-22 and HCFC-142b ended for ordinary use.

The January 1, 2020 R-22 milestone ended U.S. production and import of HCFC-22 and HCFC-142b for ordinary use; it did not make existing equipment illegal.

A is incorrect: A production/import phaseout does not automatically require destruction of existing equipment or make continued operation illegal.
B is incorrect: Recovery remains required and lawful; the 2020 milestone concerned production/import, not a ban on recovery.
C is incorrect: The 2020 milestone applied to HCFC-22 and HCFC-142b; remaining HCFC production/import is scheduled to end later.

Topic: HCFC-22 phaseout timeline

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Phaseout of Class II Ozone-Depleting Substances

Question 2.4-5

Correct answer: B. It may continue to operate and may be serviced with legally available previously produced, recovered, recycled, or reclaimed refrigerant.

Existing R-22 equipment may continue to operate and may be serviced with lawful supplies such as previously produced, recovered, recycled, or reclaimed R-22.

A is incorrect: A production/import phaseout does not automatically require destruction of existing equipment or make continued operation illegal.
C is incorrect: New U.S. production/import ended, while lawful previously produced, recovered, recycled, and reclaimed R-22 can still support existing equipment.
D is incorrect: Section 608 service and handling requirements continue even after virgin production or import ends.

Topic: Existing R-22 equipment

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Phaseout of Class II Ozone-Depleting Substances

Question 2.4-6

Correct answer: C. 2030

U.S. production and import of the remaining HCFCs is scheduled to end in 2030 under the current phaseout schedule.

A is incorrect: 1996 is the principal CFC/Class I phaseout year, not the scheduled end of remaining HCFC production/import.
B is incorrect: 2010 is an intermediate HCFC restriction milestone, not the final scheduled end of all remaining HCFC production/import.
D is incorrect: 2047 is not the current U.S. final HCFC production/import date used in this module; the U.S. schedule ends in 2030.

Topic: HCFC phaseout timeline

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Phaseout of Class II Ozone-Depleting Substances

Question 2.4-7

Correct answer: A. Production plus imports minus exports

Under the Montreal Protocol framework, consumption is generally calculated as production plus imports minus exports, subject to treaty definitions and adjustments.

B is incorrect: That describes a leak calculation concept, not Montreal Protocol consumption.
C is incorrect: Montreal Protocol consumption is an economic/control accounting term, not the installed refrigerant inventory.
D is incorrect: The simplified treaty accounting used here is production plus imports minus exports, not production minus recycled refrigerant.

Topic: Montreal Protocol consumption

EPA 608 section: Core

Difficulty: Challenging

Suggested error code: DEF

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Treaty source: UNEP — Montreal Protocol

Question 2.4-8

Correct answer: D. It added an international HFC phase-down for climate protection even though HFCs have zero ODP.

The Kigali Amendment added an international phasedown of HFCs for climate protection; HFCs have zero ODP but can have substantial climate impact.

A is incorrect: HFCs contain no chlorine and have zero ODP; Kigali addresses their climate impact.
B is incorrect: Kigali does not replace U.S. Section 608 technician-certification or service requirements.
C is incorrect: Kigali establishes a phasedown of HFC production/consumption, not an immediate shutdown of existing HFC equipment.

Topic: Kigali Amendment

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Background on HFCs and the AIM Act

Part E - Section 2.5 Concept-Check Answers

Source section: Section 2.5 - Venting Prohibition

Answer key: C B C A D B B C

Question 2.5-1

Correct answer: C. Cutting a charged R-22 line without first recovering the refrigerant

Cutting a charged R-22 line without first recovering the refrigerant knowingly releases a covered Class II refrigerant during service and violates the venting prohibition.

A is incorrect: A small residual hose loss can be de minimis when it is incidental to a compliant recovery or charging procedure.
B is incorrect: Recovering refrigerant into an appropriate cylinder is a compliant management action, not intentional venting.
D is incorrect: Nitrogen alone is exempt from the Section 608 venting prohibition after covered refrigerant has been properly removed.

Topic: Intentional venting

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.5-2

Correct answer: B. A limited incidental release associated with a good-faith recovery or recycling attempt that follows the applicable practices

A de minimis release is a limited incidental release associated with a good-faith recovery, recycling, or safe-disposal effort performed using the required practices; it is not a technician-selected fixed quantity.

A is incorrect: De minimis is not defined by a universal weight threshold or appliance charge threshold.
C is incorrect: De minimis is not defined by a universal weight threshold or appliance charge threshold.
D is incorrect: Zero ODP does not make a substitute automatically exempt from the venting prohibition.

Topic: De minimis release

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.5-3

Correct answer: C. The release can be incidental to a good-faith, compliant charging or recovery procedure.

A small hose-disconnection loss can be permitted when it is incidental to a good-faith, compliant charging or recovery procedure and the technician is minimizing releases.

A is incorrect: Connecting and disconnecting service hoses are refrigerant-handling activities and can release refrigerant.
B is incorrect: Only incidental losses tied to good-faith compliant work can qualify; deliberate or avoidable releases are not automatically exempt.
D is incorrect: Refrigerant trapped in a hose remains refrigerant; its status does not change merely because it is outside the appliance.

Topic: Hose connection and disconnection

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.5-4

Correct answer: A. They are treated separately from releases during maintenance, service, repair, or disposal, but other leak-repair or maintenance duties may apply.

Normal-operation emissions are treated separately from service venting, although separate leak-repair, maintenance, safety, or other duties may still apply.

B is incorrect: Normal-operation emissions are treated separately from service venting; the mere existence of an operational leak is not automatically the same violation.
C is incorrect: Operating the compressor does not authorize deliberate release of covered refrigerant.
D is incorrect: The normal-operation distinction is not limited to CFC refrigerants.

Topic: Normal-operation emissions

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.5-5

Correct answer: D. Carbon dioxide

Carbon dioxide is specifically exempt from the Section 608 venting prohibition in any application under the current regulation.

A is incorrect: R-410A is a non-exempt substitute refrigerant in the ordinary Section 608 context and is not broadly exempt from the venting prohibition.
B is incorrect: R-404A is a non-exempt substitute refrigerant in the ordinary Section 608 context and is not broadly exempt from the venting prohibition.
C is incorrect: R-134a is a non-exempt substitute refrigerant in the ordinary Section 608 context and is not broadly exempt from the venting prohibition.

Topic: Exempt substitutes

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.5-6

Correct answer: B. Its venting exemption applies only in the end uses specified by the current regulation.

R-290 is not universally exempt; its Section 608 venting exemption applies only in the specific end uses listed in the current regulation.

A is incorrect: Hydrocarbon exemptions are end-use specific; being a hydrocarbon does not create a universal venting exemption.
C is incorrect: R-290 is exempt in specified end uses, so saying it is never exempt is too broad.
D is incorrect: Mixing with a non-exempt refrigerant does not create an exemption.

Topic: End-use-specific exemptions

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.5-7

Correct answer: B. Recover the mixture because it contains a non-exempt refrigerant.

When nitrogen discharged from a pressure test contains R-410A or another covered refrigerant, the mixture must be recovered rather than intentionally vented.

A is incorrect: Nitrogen’s exemption does not extend to a mixture that still contains a covered refrigerant.
C is incorrect: Diluting covered refrigerant with more nitrogen does not make the refrigerant exempt.
D is incorrect: De minimis is not defined by a universal weight threshold or appliance charge threshold.

Topic: Nitrogen pressure testing

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.5-8

Correct answer: C. Knowingly releasing a covered refrigerant after recovery violates the venting prohibition.

Knowing release of a covered refrigerant remains prohibited after recovery; moving refrigerant into a recovery cylinder does not make it legal to vent.

A is incorrect: Recovery changes the refrigerant’s location, not its legal status; knowing release remains prohibited.
B is incorrect: Mixed or contaminated refrigerant still cannot be knowingly vented merely because reclamation is inconvenient.
D is incorrect: The prohibition also covers Class II refrigerants and non-exempt substitutes, not only recovered CFCs.

Topic: Recovered refrigerant and venting

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Part F - Section 2.6 Concept-Check Answers

Source section: Section 2.6 - Refrigerant Sales Restrictions

Answer key: B B C D A C A B

Question 2.6-1

Correct answer: B. Section 608 certification

Section 608 certification is the relevant federal purchase pathway for R-410A intended for a stationary split-system air conditioner.

A is incorrect: Section 609 certification is an MVAC pathway and does not by itself authorize purchase of refrigerant intended for stationary equipment.
C is incorrect: Long-lived CFCs are not rapidly removed by rain; their stability is what allows transport toward the stratosphere.
D is incorrect: Zero ODP addresses ozone depletion only; it does not by itself remove sales, service, venting, climate, or safety requirements.

Topic: Stationary refrigerant purchase authority

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Refrigerant Sales Restriction

Question 2.6-2

Correct answer: B. Yes, when the company has provided the required proof and the office manager is an authorized representative.

A qualifying employer may purchase refrigerant, and an authorized representative such as an office manager may complete the transaction when the required certification/employment documentation is in place.

A is incorrect: A qualifying employer may use an authorized representative to complete a purchase when the required documentation is in place.
C is incorrect: The employer/authorized-representative pathway applies to covered refrigerant purchases when the qualifying certification basis is documented.
D is incorrect: Employers can purchase refrigerant when they employ a properly certified technician and provide the required proof.

Topic: Employer and authorized-representative purchases

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Refrigerant Sales Restriction

Question 2.6-3

Correct answer: C. It supports purchase of refrigerant acceptable for MVAC use but does not authorize stationary-equipment refrigerant purchases.

Section 609 certification supports purchase of refrigerant acceptable for MVAC use, but it does not authorize purchase of refrigerant intended for stationary equipment.

A is incorrect: Section 609 purchase authority is limited to refrigerant acceptable for MVAC use; it is not a universal stationary-equipment credential.
B is incorrect: Section 609 and Section 608 Universal certifications cover different equipment scopes and do not replace one another.
D is incorrect: Household refrigerators are stationary appliances; Section 609 is an MVAC certification program.

Topic: Section 609 purchase limitations

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Refrigerant Sales Restriction

Question 2.6-4

Correct answer: D. A two-pound-or-less container of non-exempt substitute MVAC refrigerant with the required unique fitting and self-sealing valve

The uncertified small-can exception is limited to a non-exempt substitute intended for MVAC use in a container designed to hold two pounds or less with the required unique fitting and compliant self-sealing valve.

A is incorrect: A container designed to hold three pounds exceeds the two-pound-or-less small-can exception.
B is incorrect: The small-can exception is limited to MVAC use and does not apply to stationary heat pumps.
C is incorrect: The substitute small-can exception does not apply to CFC-12; CFC-12 is subject to the separate Section 609 purchase rule.

Topic: Small-can MVAC exception

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Refrigerant Sales Restriction

Question 2.6-5

Correct answer: A. Purchaser name, sale date, and quantity purchased

Required refrigerant-sales invoices include the purchaser’s name, date of sale, and quantity purchased.

B is incorrect: Income and vehicle-identification information are not the required retailer invoice fields.
C is incorrect: The federal sales invoice requirement discussed here does not require an appliance serial number for every refrigerant purchase.
D is incorrect: Pressure and ambient temperature are not the required sales-invoice fields.

Topic: Retailer sales records

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Recordkeeping Requirements for Refrigerant Retailers

Question 2.6-6

Correct answer: C. 3 years

Applicable refrigerant-sales records are retained for three years.

A is incorrect: The applicable retention requirement is longer than 30 days.
B is incorrect: The applicable retention requirement is three years, not one year.
D is incorrect: The specified sales records are not required to be retained permanently.

Topic: Sales-record retention

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Recordkeeping Requirements for Refrigerant Retailers

Question 2.6-7

Correct answer: A. The refrigerant must be reclaimed by an EPA-certified reclaimer.

Used refrigerant generally must be reclaimed by an EPA-certified reclaimer before it is sold to a different owner for use as refrigerant, unless a specific exception applies.

B is incorrect: Adding nitrogen does not convert recovered refrigerant into reclaimed refrigerant or authorize resale.
C is incorrect: Mixing recovered refrigerant with virgin product does not substitute for reclamation by an EPA-certified reclaimer.
D is incorrect: Recovery alone does not generally authorize sale of used refrigerant to a new owner.

Topic: Sale of used refrigerant

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Stationary Refrigeration Refrigerant Reclamation Requirements

Question 2.6-8

Correct answer: B. The refrigerant sales restriction generally does not require purchaser certification when refrigerant is contained in the fully assembled appliance circuit.

Purchaser certification is generally not required when refrigerant is contained in the fully assembled refrigerant circuit of a factory-charged appliance being sold as equipment.

A is incorrect: The sales restriction generally does not require the consumer to be technician-certified merely to buy a complete factory-charged appliance.
C is incorrect: Section 609 applies to MVAC service, not ordinary purchase of a household refrigerator.
D is incorrect: Factory-charged appliances may be sold with refrigerant contained in the fully assembled circuit.

Topic: Sale of refrigerant-containing appliances

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.6 - Refrigerant Sales Restrictions

Regulatory source: EPA — Refrigerant Sales Restriction

Part G - Section 2.7 Concept-Check Answers

Source section: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Answer key: C C B A B C A C

Question 2.7-1

Correct answer: C. An uncertified worker uses another technician’s certification number to purchase refrigerant for personal work.

Using another technician’s certification number to support an uncertified person’s personal refrigerant purchase is credential misuse.

A is incorrect: An authorized purchasing agent acting for a qualifying employer is a lawful purchasing arrangement, not credential misuse.
B is incorrect: Keeping a backup copy of one’s own certification is prudent recordkeeping, not misuse.
D is incorrect: Seller verification of certification is a compliance step, not misuse.

Topic: Certification misuse

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: 40 CFR § 82.161 — Technician Certification

Question 2.7-2

Correct answer: C. 3 years

A Section 608 technician must retain a copy of the certification until three years after the person stops operating as a technician.

A is incorrect: The applicable retention requirement is longer than 30 days.
B is incorrect: The applicable retention requirement is three years, not one year.
D is incorrect: The technician-certification copy has a defined retention period after the person stops operating as a technician; it is not an indefinite federal requirement in every case.

Topic: Technician certification records

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: 40 CFR § 82.161 — Technician Certification

Question 2.7-3

Correct answer: B. Evacuating an appliance with more than 5 and less than 50 pounds of refrigerant for disposal

The specific disposal recordkeeping provision discussed in Section 2.7 applies when a technician evacuates an appliance with more than 5 pounds and less than 50 pounds of refrigerant for disposal.

A is incorrect: The specific disposal-record provision begins above 5 pounds; exactly 5 pounds is outside the stated range.
C is incorrect: The record requirement is tied to the specific disposal range, not to every service event below 200 pounds.
D is incorrect: Buying a recovery cylinder is not the disposal activity that triggers this technician record requirement.

Topic: Disposal recordkeeping

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: 40 CFR § 82.156 — Required Practices

Question 2.7-4

Correct answer: A. Purchaser name, sale date, and quantity purchased

The required refrigerant-sales invoice includes purchaser name, sale date, and quantity purchased.

B is incorrect: Those operating details are not the required federal refrigerant-sales invoice fields.
C is incorrect: Wage, vehicle, and service-address data are not the required sales-invoice fields.
D is incorrect: A recovery-machine serial number is not one of the required retailer sales-invoice fields.

Topic: Retailer records

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: EPA — Recordkeeping Requirements for Refrigerant Retailers

Question 2.7-5

Correct answer: B. Records can include full charge, service events, refrigerant additions, leak inspections, and verification-test results.

For applicable 50-pound-or-more ODS appliances, owner/operator records can include full charge, service events, refrigerant additions, leak inspections, and verification-test results.

A is incorrect: Applicable large-ODS-appliance records extend well beyond the original installation invoice.
C is incorrect: Service, leak, and charge records are created during the appliance’s operating life, not only after retirement.
D is incorrect: Where the regulation assigns records to the owner/operator, the technician must provide the required service documentation.

Topic: Owner/operator records

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: EPA — Recordkeeping and Reporting Requirements for Stationary Refrigeration

Question 2.7-6

Correct answer: C. By March 1 of the following year

When an applicable appliance leaks 125 percent or more of its full charge in a calendar year, the chronically leaking appliance report is generally due by March 1 of the following year.

A is incorrect: The chronic-leak report is not generally due within 24 hours.
B is incorrect: That date cannot serve as the following-year reporting deadline for a calendar-year loss.
D is incorrect: The reporting duty is triggered by the regulation; it does not depend on EPA first making a special request.

Topic: Chronic-leak reporting

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: 40 CFR § 82.157 — Appliance Maintenance and Leak Repair

Question 2.7-7

Correct answer: A. Penalties are adjusted for inflation and depend on the statutory provision and enforcement pathway.

Older fixed penalty figures must be verified because federal civil monetary penalties are adjusted and depend on the statutory authority and enforcement pathway.

B is incorrect: Technician certification does not cancel statutory penalties for violations.
C is incorrect: Federal civil penalties are established by law and regulation, not selected by refrigerant manufacturers.
D is incorrect: Section 608 and Clean Air Act violations remain enforceable.

Topic: Penalty verification

EPA 608 section: Core

Difficulty: Standard

Suggested error code: LEG

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: 40 CFR § 19.4 — Statutory Civil Monetary Penalties

Question 2.7-8

Correct answer: C. Refuse to falsify the record, stop the improper action, and use the employer’s compliance or reporting process.

A technician should refuse to falsify a recovery record, stop the improper action, and use the employer’s compliance or reporting process rather than participate in venting or false documentation.

A is incorrect: A supervisor’s instruction does not justify signing a false record or participating in a violation.
B is incorrect: Leaving a field blank does not correct the underlying venting violation or the duty to keep accurate records.
D is incorrect: Entering a knowingly false quantity is still falsification.

Topic: Professional responsibility

EPA 608 section: Core

Difficulty: Standard

Suggested error code: SAF

Review: Section 2.7 - Enforcement Recordkeeping and Professional Responsibility

Regulatory source: EPA — Enforcement Actions under Title VI of the Clean Air Act

Part H - Section 2.8 Concept-Check Answers

Source section: Section 2.8 - Current and Historical Regulation Comparison

Answer key: C B C B B C C C

Question 2.8-1

Correct answer: C. 20%

The current Section 608 leak-repair trigger for qualifying commercial refrigeration appliances is 20 percent.

A is incorrect: 10 percent is the current comfort-cooling/other trigger, not the current commercial-refrigeration trigger.
B is incorrect: 15 percent is a historical comfort-cooling trigger, not the current commercial-refrigeration trigger.
D is incorrect: 35 percent is the historical commercial/IPR trigger, not the current commercial-refrigeration trigger.

Topic: Current leak-repair trigger rates

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: 40 CFR § 82.157 — Appliance Maintenance and Leak Repair

Question 2.8-2

Correct answer: B. Section 608 applies to qualifying 50-pound-or-more ODS appliances, while the AIM Act can apply to qualifying 15-pound-or-more appliances containing HFCs or certain substitutes.

Current Section 608 leak repair applies to qualifying 50-pound-or-more ODS appliances, while separate AIM Act leak-repair provisions can apply to qualifying 15-pound-or-more appliances containing HFCs or certain substitutes.

A is incorrect: The two programs have different refrigerant scopes and full-charge thresholds.
C is incorrect: The AIM Act did not replace Section 608; both programs remain in force with different scopes.
D is incorrect: Section 608 applies across qualifying stationary appliance categories, not only residential systems.

Topic: Section 608 versus AIM Act leak repair

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: 40 CFR § 84.106 — Leak Repair

Question 2.8-3

Correct answer: C. It was extended to non-exempt substitute refrigerants such as common HFCs.

Beginning January 1, 2018, the federal refrigerant-sales restriction was extended to non-exempt substitute refrigerants, including common HFCs.

A is incorrect: The 2018 change expanded the sales restriction; it did not eliminate it.
B is incorrect: The sales restriction covers multiple Class I, Class II, and non-exempt substitute refrigerants, not only R-22.
D is incorrect: Valid pre-2018 Section 608 cards remain valid; the rule change did not require universal card replacement.

Topic: Historical versus current sales restrictions

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: EPA — Refrigerant Sales Restriction

Question 2.8-4

Correct answer: B. ARI Standard 740-1995

Recovery or recycling equipment manufactured or imported from September 22, 2003 through December 31, 2016 is associated with ARI Standard 740-1995 under the current regulatory framework.

A is incorrect: The 1993 edition retains its historical ARI designation; it is not renamed AHRI.
C is incorrect: AHRI 740-2016 applies to the specified equipment manufactured or imported on or after January 1, 2017, not the 2003–2016 category.
D is incorrect: This is not the recovery-equipment standard identified for the 2003–2016 manufacture/import period.

Topic: Recovery-equipment standards

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: 40 CFR § 82.158 — Standards for Recovery and Recycling Equipment

Question 2.8-5

Correct answer: B. Penalty maximums are inflation adjusted and depend on the statutory authority and enforcement pathway.

A $37,500-per-day figure is a historical maximum from an older period; current maximums are inflation adjusted and depend on the applicable statutory and enforcement pathway.

A is incorrect: Clean Air Act violations can still lead to civil penalties.
C is incorrect: The $37,500 figure is historical and is not the universal current amount.
D is incorrect: Federal civil penalties are established by law and regulation, not selected by refrigerant manufacturers.

Topic: Historical versus current penalties

EPA 608 section: Core

Difficulty: Standard

Suggested error code: LEG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: 40 CFR § 19.4 — Statutory Civil Monetary Penalties

Question 2.8-6

Correct answer: C. Date the recovery or recycling equipment was manufactured or imported

The applicable recovery-equipment certification standard is determined by the recovery or recycling equipment’s manufacture or import date.

A is incorrect: The recovery-equipment standard is tied to the recovery/recycling machine’s manufacture or import date, not the appliance installation date.
B is incorrect: Technician certification date does not determine the recovery-machine standard.
D is incorrect: Cylinder filling date does not determine the recovery-machine standard.

Topic: Recovery-equipment date rules

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: 40 CFR § 82.158 — Standards for Recovery and Recycling Equipment

Question 2.8-7

Correct answer: C. AHRI is the current organization name, but historical standards such as ARI 740-1993 retain their original designation.

AHRI is the current organization name, but historical standards retain their original ARI designations, such as ARI 740-1993 and ARI 740-1995.

A is incorrect: Historical standards retain the organization designation under which they were issued or incorporated.
B is incorrect: AHRI is the successor organization formed after ARI combined with the Gas Appliance Manufacturers Association.
D is incorrect: AHRI terminology and standards are used broadly in HVAC/R and are not limited to MVAC equipment.

Topic: ARI versus AHRI terminology

EPA 608 section: Core

Difficulty: Standard

Suggested error code: LEG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: 40 CFR § 82.158 — Standards for Recovery and Recycling Equipment

Question 2.8-8

Correct answer: C. Label 35 percent as historical and teach the current 20-percent rule with its applicability and verification date.

A legacy question using 35 percent for commercial refrigeration should be labeled historical; the current Section 608 trigger is 20 percent for qualifying appliances, with the current applicability clearly stated.

A is incorrect: That would preserve an outdated answer and misstate the current rule.
B is incorrect: Historical values remain useful when clearly labeled; the correct response is to distinguish them from current requirements.
D is incorrect: Regulatory thresholds are not determined by averaging historical and current values.

Topic: Legacy question handling

EPA 608 section: Core

Difficulty: Standard

Suggested error code: LEG

Review: Section 2.8 - Current and Historical Regulation Comparison

Regulatory source: 40 CFR § 82.157 — Appliance Maintenance and Leak Repair

Part I - Section 2.10 Module Practice-Question Answers

Source section: Section 2.10 - Practice Questions

Answer key: B D A C B C A D C A D B C A D B C A D B C A B D A C D B A C B D A C B

Question 2.10-1

Correct answer: B. It absorbs much of the Sun’s harmful ultraviolet radiation.

The stratospheric ozone layer protects life by absorbing much of the Sun’s harmful ultraviolet radiation, especially most UVB and essentially all UVC.

A is incorrect: The ozone layer’s principal protective role is ultraviolet absorption, not trapping all outgoing infrared radiation.
C is incorrect: The ozone layer is an atmospheric UV shield, not an oxygen-production system for refrigeration equipment.
D is incorrect: Stratospheric ozone does not act as a barrier preventing carbon dioxide from entering the troposphere.

Topic: Ozone-layer function

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.10-2

Correct answer: D. Ground-level ozone is a harmful pollutant, while stratospheric ozone provides important UV protection.

Ground-level ozone and stratospheric ozone are both $O_{3}$ , but ground-level ozone is a harmful pollutant while stratospheric ozone provides important UV protection.

A is incorrect: Ground-level ozone is a harmful air pollutant; it is not beneficial at all concentrations.
B is incorrect: This reverses the roles: stratospheric ozone protects against UV, while ground-level ozone contributes to pollution.
C is incorrect: Both are the same molecule, $O_{3}$ ; their different effects arise from atmospheric location.

Topic: Ground-level versus stratospheric ozone

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.10-3

Correct answer: A. UVC

UVC is absorbed very strongly by atmospheric oxygen and ozone and therefore does not normally reach Earth’s surface in significant amounts.

B is incorrect: UVA is only weakly absorbed by ozone, so ozone depletion is most directly associated with increased UVB rather than UVA.
C is incorrect: UVB is only partly absorbed and some reaches the surface; UVC is the band normally absorbed so strongly that essentially none reaches the surface.
D is incorrect: Infrared radiation is not an ultraviolet band.

Topic: Ultraviolet radiation

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.10-4

Correct answer: C. More UVB can reach Earth’s surface.

Loss of stratospheric ozone allows more UVB to reach Earth’s surface.

A is incorrect: Ozone depletion is most directly associated with increased UVB at the surface, not simply decreased UVA.
B is incorrect: Ozone depletion does not cause all ultraviolet radiation to be blocked; it reduces shielding.
D is incorrect: Stratospheric ozone depletion does not automatically eliminate ground-level ozone pollution.

Topic: Ozone depletion and UVB

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Scientific source: EPA — Information on Ozone and Ozone Depletion

Question 2.10-5

Correct answer: B. They can survive long enough to be transported through the atmosphere into the stratosphere.

Long-lived CFCs and HCFCs can survive long enough in the lower atmosphere to be transported by atmospheric circulation into the stratosphere.

A is incorrect: Long-range atmospheric transport is driven by atmospheric circulation and chemical lifetime, not by a simple ‘lighter than air’ explanation.
C is incorrect: Long-lived CFCs are not rapidly removed by rain; their stability is what allows transport toward the stratosphere.
D is incorrect: Long-lived ODS can have important stratospheric effects after atmospheric transport, so their impact is not limited to ground level.

Topic: Transport of ozone-depleting substances

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.10-6

Correct answer: C. Strong ultraviolet radiation that breaks the molecules apart

Strong stratospheric ultraviolet radiation breaks chlorine-containing ODS molecules and releases reactive chlorine species.

A is incorrect: Refrigeration-coil condensation does not release stratospheric chlorine from ODS molecules.
B is incorrect: The activating process is energetic UV photolysis, not high pressure.
D is incorrect: The key activation occurs in the stratosphere through UV photolysis, not contact with surface liquid water.

Topic: Photolysis of ozone-depleting substances

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.10-7

Correct answer: A. The chlorine atom is regenerated during the catalytic reaction cycle.

Reactive chlorine is regenerated in the catalytic cycle, allowing one atom to participate in many ozone-destruction reactions.

B is incorrect: The key catalytic feature is that chlorine is regenerated rather than permanently consumed.
C is incorrect: Catalytic chlorine is regenerated rather than consumed after one reaction.
D is incorrect: Chlorine catalyzes chemical reactions; it does not create the ultraviolet radiation driving photolysis.

Topic: Catalytic ozone destruction

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.10-8

Correct answer: D. Bromine can participate in catalytic and coupled ozone-destruction chemistry.

Bromine can participate in catalytic and coupled ozone-destruction chemistry and is therefore important to stratospheric ozone depletion.

A is incorrect: Bromine is an important participant in catalytic stratospheric ozone destruction.
B is incorrect: Reactive bromine species can participate directly in ozone-destruction chemistry.
C is incorrect: Bromine’s ozone-depletion role is a stratospheric chemistry issue, not only a ground-level smog issue.

Topic: Bromine ozone chemistry

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Scientific source: EPA — Basic Ozone Layer Science

Question 2.10-9

Correct answer: C. CFC-11

CFC-11 is the reference substance assigned an ozone-depletion potential of 1.0.

A is incorrect: Carbon dioxide is the GWP reference gas, not the ODP reference substance.
B is incorrect: HFC-134a is an HFC with zero ODP; it is not the ODP reference substance.
D is incorrect: R-717 is ammonia, not the GWP reference gas.

Topic: Ozone-depletion potential

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.10-10

Correct answer: A. Carbon dioxide

Carbon dioxide is the reference gas assigned a global-warming potential of 1.

B is incorrect: CFC-11 is the ODP reference substance, not the GWP reference gas.
C is incorrect: HCFC-22 is not the GWP reference gas.
D is incorrect: HFO-1234yf has a very low GWP in the reference table but is not the reference gas assigned GWP 1 by definition.

Topic: Global-warming potential

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.10-11

Correct answer: D. HCFCs contain hydrogen, carbon, chlorine, and fluorine.

HCFCs contain hydrogen, carbon, chlorine, and fluorine.

A is incorrect: HCFCs contain chlorine as well as hydrogen, carbon, and fluorine.
B is incorrect: HFCs do not contain chlorine.
C is incorrect: Common HFOs are hydrofluoroolefins and do not contain chlorine.

Topic: HCFC composition

EPA 608 section: Core

Difficulty: Basic

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.10-12

Correct answer: B. They have zero ODP but can still have significant GWP.

HFCs have zero ODP because they contain no chlorine, but many still have significant GWP.

A is incorrect: HFCs contain no chlorine and therefore have zero ODP.
C is incorrect: Zero ODP addresses ozone depletion only; it does not by itself remove sales, service, venting, climate, or safety requirements.
D is incorrect: HFCs are not exempt from all Section 608 provisions; several certification, venting, sales, recovery, and disposal requirements can apply.

Topic: HFC environmental effects

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.10-13

Correct answer: C. A carbon-carbon double bond

Common HFOs contain a carbon-carbon double bond, which distinguishes them from conventional saturated HFCs and contributes to shorter atmospheric lifetime.

A is incorrect: Chlorine is not the defining feature of an HFO.
B is incorrect: HFOs are carbon-containing organic compounds.
D is incorrect: Ammonia is R-717 and is not an HFO.

Topic: HFO composition and behavior

EPA 608 section: Core

Difficulty: Standard

Suggested error code: DEF

Review: Section 2.3 - Refrigerant Families ODP and GWP

Scientific/regulatory source: EPA — Ozone-Depleting Substances

Question 2.10-14

Correct answer: A. The Montreal Protocol was adopted.

The Montreal Protocol was adopted in 1987 as the international agreement controlling ozone-depleting substances.

B is incorrect: The U.S. HCFC-22 production/import milestone occurred in 2020, not 1987.
C is incorrect: The Kigali Amendment was adopted in 2016, not 1987.
D is incorrect: The substitute-refrigerant sales restriction extension became effective in 2018, not 1987.

Topic: Montreal Protocol timeline

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Treaty source: UNEP — Montreal Protocol

Question 2.10-15

Correct answer: D. A production or import phaseout does not automatically prohibit continued operation of existing equipment using lawful refrigerant supplies.

A production or import phaseout does not automatically prohibit continued operation of existing equipment using lawful supplies of previously produced, recovered, recycled, or reclaimed refrigerant.

A is incorrect: A production/import phaseout does not automatically require destruction of existing equipment or make continued operation illegal.
B is incorrect: Recovered, recycled, or reclaimed refrigerant can remain lawful for servicing existing equipment where permitted.
C is incorrect: Section 608 service requirements continue even after production/import phaseout.

Topic: Phaseout versus equipment-use ban

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Ozone Protection under Title VI of the Clean Air Act

Question 2.10-16

Correct answer: B. U.S. production and import of HCFC-22 ended.

The 2020 U.S. HCFC-22 milestone ended production and import of HCFC-22 for ordinary use; it did not make existing R-22 appliances illegal.

A is incorrect: A production/import phaseout does not automatically require destruction of existing equipment or make continued operation illegal.
C is incorrect: Reclaimed R-22 remains an important lawful source for servicing existing equipment.
D is incorrect: The Montreal Protocol was adopted in 1987, not in 2020.

Topic: HCFC-22 phaseout timeline

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Phaseout of Class II Ozone-Depleting Substances

Question 2.10-17

Correct answer: C. It addresses the phasedown of HFCs for climate protection.

The Kigali Amendment addresses the phasedown of HFCs for climate protection even though HFCs have zero ODP.

A is incorrect: The Kigali Amendment concerns HFC phasedown, not the origin of Section 608 certification categories.
B is incorrect: The Kigali Amendment did not establish the U.S. small-appliance definition.
D is incorrect: Kigali phases down HFCs; it does not require replacing HFC systems with ozone-depleting CFCs.

Topic: Kigali Amendment

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Review: Section 2.4 - Clean Air Act and Montreal Protocol

Regulatory source: EPA — Background on HFCs and the AIM Act

Question 2.10-18

Correct answer: A. Knowingly releasing a non-exempt refrigerant while repairing an appliance

Knowingly releasing a non-exempt refrigerant while repairing an appliance is directly within the Section 608 venting prohibition.

B is incorrect: Water vapor is not the non-exempt refrigerant service release addressed by the question.
C is incorrect: Nitrogen alone is exempt from the Section 608 venting prohibition.
D is incorrect: Purchasing equipment is not the covered maintenance/service release described by the venting question.

Topic: Intentional venting

EPA 608 section: Core

Difficulty: Basic

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.10-19

Correct answer: D. A small hose-disconnection loss incidental to a good-faith recovery effort using required practices

A small hose-disconnection loss can qualify as de minimis when it is incidental to a good-faith compliant recovery effort using required practices.

A is incorrect: Deliberately purging refrigerant for convenience is not an incidental de minimis release.
B is incorrect: Dumping a recovery cylinder to avoid reclamation cost is a deliberate release, not de minimis.
C is incorrect: De minimis is not a technician-created fixed allowance.

Topic: De minimis release

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.10-20

Correct answer: B. Normal-operation emissions are treated separately from service venting, but other leak-repair, safety, or maintenance duties may still apply.

Normal-operation emissions are treated separately from service venting, but separate leak-repair, maintenance, safety, or other duties can still apply.

A is incorrect: Normal-operation emissions are treated separately from service venting; the mere existence of an operational leak is not automatically the same violation.
C is incorrect: The normal-operation category does not authorize deliberate creation of a refrigerant release.
D is incorrect: Normal-operation emissions and de minimis service releases are different regulatory concepts.

Topic: Normal-operation emissions

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.10-21

Correct answer: C. Recover the mixture rather than intentionally venting it.

Nitrogen does not make a covered refrigerant exempt; a nitrogen/refrigerant mixture must be recovered instead of intentionally vented.

A is incorrect: The mixture contains a covered refrigerant; nitrogen’s exemption does not extend to the refrigerant.
B is incorrect: Diluting covered refrigerant with more nitrogen does not make the refrigerant exempt.
D is incorrect: Outdoor location does not make intentional venting of covered refrigerant lawful.

Topic: Nitrogen pressure testing

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG

Regulatory source: 40 CFR § 82.154 — Prohibitions

Question 2.10-22

Correct answer: A. Carbon dioxide, nitrogen, and water

Carbon dioxide, nitrogen, and water are identified in this module as broadly exempt from the Section 608 venting prohibition in any application.

B is incorrect: Ammonia and hydrocarbon exemptions are end-use specific, not universal in every application.
C is incorrect: These common HFC refrigerants are not broadly exempt from the venting prohibition.
D is incorrect: CFCs and HCFCs are ozone-depleting refrigerants covered by the venting prohibition.

Topic: Broad venting exemptions

EPA 608 section: Core

Difficulty: Standard

Suggested error code: REG