10.12 - Universal Mock Examination 2 Answers

Purpose: Detailed post-examination review for the corresponding 100-question Universal mock examination
Regulatory verification date: August 14, 2026
Review rule: For every missed or guessed question, identify the controlling condition and explain why each competing option is wrong before marking the item corrected.

How to Use This File

1. Complete the corresponding mock examination closed-book before opening this file.
2. Score Core, Type I, Type II, and Type III separately.
3. Review every missed question and every correct answer that was guessed or uncertain.
4. Enter unresolved items in 10.10 - Error Analysis and Remediation.md.
5. For a current regulatory question, memorize the condition together with the rule or number.

Core Answers — Questions 1–25

Question 1

Correct answer: D. Stratosphere

The protective ozone layer is primarily in the stratosphere.

• A is incorrect: The mesosphere is above the stratosphere and is not where the protective ozone layer is concentrated.
• B is incorrect: The thermosphere is much higher and is not the protective ozone layer location.
• C is incorrect: Ground-level/tropospheric ozone is a pollutant and is not the protective ozone layer being referenced.

Topic: Atmospheric ozone location
EPA 608 section: Core
Error category: DEF

Question 2

Correct answer: C. HFC

HFCs contain no chlorine or bromine, so their ODP is zero, although many have significant GWP.

• A is incorrect: CFCs contain chlorine and have nonzero ODP.
• B is incorrect: HCFCs contain chlorine and have nonzero ODP.
• D is incorrect: Halons contain bromine and are potent ozone-depleting substances.

Topic: ODP versus GWP
EPA 608 section: Core
Error category: DEF

Question 3

Correct answer: A. Clean Air Act

Section 608 is part of the Clean Air Act.

• B is incorrect: OSHA rules address workplace safety but are not the legal basis of Section 608.
• C is incorrect: The NEC addresses electrical installations, not Section 608 refrigerant management.
• D is incorrect: The Safe Drinking Water Act is unrelated to Section 608 technician certification.

Topic: Clean Air Act basis
EPA 608 section: Core
Error category: DEF

Question 4

Correct answer: D. Zero ODP alone does not create a venting exemption; covered substitutes may not be intentionally vented.

Most non-exempt substitutes remain subject to the venting prohibition even though they have zero ODP.

• A is incorrect: The venting prohibition is not limited to CFCs.
• B is incorrect: Residential use does not create a general venting exemption.
• C is incorrect: The small-appliance charge limit does not authorize intentional venting.

Topic: Venting of substitute refrigerants
EPA 608 section: Core
Error category: REG
Regulatory basis: 40 CFR § 82.154

Question 5

Correct answer: C. A person adding refrigerant to a stationary heat pump

Adding refrigerant is specifically a technician activity.

• A is incorrect: Painting does not normally disturb the refrigerant circuit.
• B is incorrect: Floor cleaning is unrelated to the refrigerant circuit.
• D is incorrect: A building light fixture is outside the appliance refrigerant circuit.

Topic: Technician definition
EPA 608 section: Core
Error category: REG
Regulatory basis: 40 CFR § 82.152

Question 6

Correct answer: A. Type II Section 608 or the applicable Section 609 certification pathway

Qualifying MVAC-like appliances may be serviced under Type II or the applicable Section 609 pathway.

• B is incorrect: Type III is for low-pressure appliances.
• C is incorrect: Type I is for small appliances.
• D is incorrect: The MVAC-like certification requirement is not removed simply because there is no compensation.

Topic: MVAC-like appliance certification
EPA 608 section: Core
Error category: CLS
Regulatory basis: 40 CFR §§ 82.152, 82.161 and EPA 608/609 overlap guidance

Question 7

Correct answer: B. Recycled

Recycling means cleaning recovered refrigerant for permitted reuse without meeting all reclamation requirements.

• A is incorrect: Reclamation requires reprocessing to the applicable purity specification and analytical verification.
• C is incorrect: The refrigerant has not been destroyed.
• D is incorrect: Cleaning used refrigerant is not manufacturing new refrigerant.

Topic: Recycle definition
EPA 608 section: Core
Error category: DEF
Regulatory basis: 40 CFR § 82.152

Question 8

Correct answer: A. It must be reprocessed to the applicable purity specifications and verified using the prescribed analytical method.

Reclamation requires both processing to the applicable specifications and analytical verification.

• B is incorrect: Mixing does not constitute reclamation and may contaminate refrigerant.
• C is incorrect: 130°F is a Type III oil-service exam value, not a reclamation standard.
• D is incorrect: Changing cylinders does not establish refrigerant purity.

Topic: Reclaim definition
EPA 608 section: Core
Error category: DEF
Regulatory basis: 40 CFR § 82.152 and Appendix A to Subpart F

Question 9

Correct answer: B. Recovery slows because the pressure difference driving refrigerant flow is reduced.

Higher cylinder pressure reduces the pressure differential and can slow recovery.

• A is incorrect: Higher receiving-cylinder pressure generally opposes refrigerant flow rather than speeding it.
• C is incorrect: Reclamation requires specified reprocessing and analytical verification.
• D is incorrect: A recovery machine still requires its designed heat-rejection components.

Topic: Recovery speed and backpressure
EPA 608 section: Core
Error category: PRO

Question 10

Correct answer: D. Confirm that the refrigerant is the same before combining it.

Recovered refrigerant should be kept in a compatible, correctly identified cylinder and not mixed with a different refrigerant.

• A is incorrect: Low pressure does not make contents irrelevant.
• B is incorrect: Zero ODP does not make mixed refrigerants compatible.
• C is incorrect: Nitrogen does not separate refrigerants inside a cylinder and adds contamination.

Topic: Avoiding refrigerant mixing
EPA 608 section: Core
Error category: SAF

Question 11

Correct answer: B. A recovery machine captures refrigerant; a vacuum pump is primarily used to evacuate air and moisture after recovery.

Recovery captures refrigerant; evacuation/dehydration uses a vacuum pump after refrigerant removal.

• A is incorrect: Neither device is intended to vent refrigerant intentionally.
• C is incorrect: A recovery container is still needed for recovered refrigerant.
• D is incorrect: Pressure measurement is the role of gauges, not the primary function of a recovery machine.

Topic: Recovery versus evacuation equipment
EPA 608 section: Core
Error category: DEF

Question 12

Correct answer: D. 5 psig

Gauge pressure is approximately 19.7 - 14.7 = 5 psig.

• A is incorrect: Zero gauge pressure would correspond to about 14.7 psia under the stated condition.
• B is incorrect: 34.4 psig results from adding rather than subtracting atmospheric pressure.
• C is incorrect: 14.7 psig would correspond to about 29.4 psia.

Topic: Gauge and absolute pressure
EPA 608 section: Core
Error category: CAL

Question 13

Correct answer: D. On an absolute-pressure scale, a smaller value indicates a deeper vacuum.

Absolute pressure approaches zero as vacuum deepens.

• A is incorrect: Absolute pressure cannot be negative.
• B is incorrect: On an in. Hg vacuum scale referenced to atmosphere, a larger value generally represents a deeper vacuum.
• C is incorrect: The units and reference points are different.

Topic: Vacuum scales
EPA 608 section: Core
Error category: CAL

Question 14

Correct answer: C. 6°F

Subcooling = saturation bubble-point temperature - measured liquid temperature = 72°F - 66°F = 6°F.

• A is incorrect: 72°F is the saturation reference, not the amount of subcooling.
• B is incorrect: The sign is reversed.
• D is incorrect: Adding the temperatures is not the subcooling calculation.

Topic: Blend subcooling calculation
EPA 608 section: Core
Error category: CAL

Question 15

Correct answer: A. To verify the repair and avoid losing newly added refrigerant.

Leak checking confirms system integrity before refrigerant is added or returned.

• B is incorrect: ODP is not changed by a leak test.
• C is incorrect: Leak checking and evacuation serve different purposes.
• D is incorrect: Oxygen is not a proper refrigerant-system pressure-test gas.

Topic: Leak checking before charging
EPA 608 section: Core
Error category: PRO

Question 16

Correct answer: B. Refrigeration oil

POE and some other lubricants are hygroscopic and can absorb moisture that contaminates the system.

• A is incorrect: Paint moisture is not the refrigerant-circuit concern.
• C is incorrect: External insulation is not the lubricant.
• D is incorrect: Thermostat wire is not the moisture-sensitive refrigerant lubricant.

Topic: Lubricant hygroscopicity
EPA 608 section: Core
Error category: SAF

Question 17

Correct answer: A. To control the very high cylinder pressure delivered to the system.

Cylinder pressure is far above normal appliance test pressure, so regulated delivery is essential.

• B is incorrect: Nitrogen does not become refrigerant.
• C is incorrect: The regulator reduces, not increases, delivery pressure.
• D is incorrect: Relief protection remains important downstream.

Topic: Nitrogen regulator safety
EPA 608 section: Core
Error category: SAF

Question 18

Correct answer: C. Displace oxygen and create an asphyxiation hazard.

Many refrigerants are heavier than air and can displace oxygen in low areas.

• A is incorrect: A refrigerant release does not increase oxygen to 100%.
• B is incorrect: Refrigerants do not make all materials noncombustible.
• D is incorrect: They do not automatically make electrical equipment safe.

Topic: Asphyxiation hazard
EPA 608 section: Core
Error category: SAF

Question 19

Correct answer: B. Heat a recovery cylinder with an open flame to increase pressure.

Open-flame heating can cause dangerous overpressure and decomposition and must not be used.

• A is incorrect: A scale is an important fill-control tool.
• C is incorrect: Excess heat should be avoided.
• D is incorrect: Securing cylinders reduces transport hazards.

Topic: Cylinder handling safety
EPA 608 section: Core
Error category: SAF

Question 20

Correct answer: B. A slower pressure rise that tends to stabilize

A slower rise that trends toward stabilization can be associated with moisture/outgassing.

• A is incorrect: A rapid return to atmosphere suggests a major leak/open path.
• C is incorrect: An open hose is an obvious leak.
• D is incorrect: An intentionally open valve is not a moisture indication.

Topic: Standing vacuum moisture indication
EPA 608 section: Core
Error category: PRO

Question 21

Correct answer: C. Appropriate verification such as the required signed statement or qualifying contract

The safe-disposal pathway allows documented verification of prior recovery.

• A is incorrect: An undocumented verbal assurance is inadequate.
• B is incorrect: A sticker alone is not sufficient verification.
• D is incorrect: Connecting nitrogen does not establish prior refrigerant recovery.

Topic: Safe-disposal verification
EPA 608 section: Core
Error category: REG
Regulatory basis: Current EPA safe-disposal requirements

Question 22

Correct answer: A. Company name, appliance location, date of recovery, and refrigerant type

The current rule requires company name, appliance location, recovery date, and refrigerant type for each applicable appliance, plus additional aggregate transfer records.

• B is incorrect: A certification number alone does not satisfy the record content.
• C is incorrect: A machine serial number alone does not satisfy the rule.
• D is incorrect: Cylinder weight alone does not satisfy the required record content.

Topic: Disposal record contents
EPA 608 section: Core
Error category: REG
Regulatory basis: 40 CFR § 82.156(a)(3)

Question 23

Correct answer: C. It can describe a Type I recovery requirement under certain conditions and also a separate recovery-cylinder fill safety concept.

The same 80% number appears in two separate contexts and must not be confused.

• A is incorrect: Type III evacuation is 25 mm Hg absolute.
• B is incorrect: The current commercial leak-rate trigger is 20%, not 80%.
• D is incorrect: Nitrogen-cylinder pressure is not defined by an 80% value.

Topic: Commonly confused 80% values
EPA 608 section: Core
Error category: DIST

Question 24

Correct answer: D. Type III

Core plus Type III earns Type III certification.

• A is incorrect: Universal requires all three type sections plus Core.
• B is incorrect: Section 609 is a separate MVAC certification program.
• C is incorrect: Type I requires the Type I section.

Topic: Certification combinations
EPA 608 section: Core
Error category: CLS
Regulatory basis: 40 CFR § 82.161

Question 25

Correct answer: A. An open-book Core result

EPA states that an open-book Core result cannot be used to obtain Universal certification.

• B is incorrect: Closed-book Core under the accepted secure pathway is appropriate.
• C is incorrect: A qualifying secure proctored Core result can be used.
• D is incorrect: Core taken under the qualifying Universal conditions can be used.

Topic: Universal open-book limitation
EPA 608 section: Core
Error category: REG
Regulatory basis: Current EPA Section 608 certification guidance

Type I Answers — Questions 26–50

Question 26

Correct answer: D. The appliance must be fully manufactured, charged, and hermetically sealed at a factory.

The definition requires all of the factory manufacture, factory charge, factory hermetic seal, and 5-lb-or-less conditions.

• A is incorrect: Motor-vehicle equipment is governed by the MVAC/MVAC-like framework, not the small-appliance definition.
• B is incorrect: A field-installed line set is inconsistent with the complete factory-manufactured/charged/sealed small-appliance definition.
• C is incorrect: Low-pressure classification would point to Type III, not define a small appliance.

Topic: Small-appliance definition conditions
EPA 608 section: Type I
Error category: CLS
Regulatory basis: 40 CFR § 82.152

Question 27

Correct answer: A. Field-installed mini-split with a 3.8-lb charge

A field-installed mini-split is not fully factory-manufactured/charged/hermetically sealed as the complete system and is normally Type II.

• B is incorrect: A qualifying dehumidifier can be a small appliance.
• C is incorrect: A qualifying drinking-water cooler is a listed small-appliance example.
• D is incorrect: A qualifying under-counter ice maker is a listed small-appliance example.

Topic: Type I exclusions
EPA 608 section: Type I
Error category: CLS
Regulatory basis: 40 CFR § 82.152

Question 28

Correct answer: B. 80%

Pre-November 15, 1993 recovery equipment uses the 80% requirement.

• A is incorrect: Seventy percent is not the requirement.
• C is incorrect: Ninety percent is the post-1993 functional-compressor condition.
• D is incorrect: One hundred percent is not the specified percentage option.

Topic: Pre-1993 Type I recovery
EPA 608 section: Type I
Error category: REG
Regulatory basis: 40 CFR § 82.156(b)

Question 29

Correct answer: B. 4 in. Hg vacuum

Four inches of Hg vacuum is the current small-appliance alternative.

• A is incorrect: Zero is not the small-appliance alternative endpoint.
• C is incorrect: 25 mm Hg absolute is the low-pressure appliance endpoint.
• D is incorrect: Ten inches is a Type II table value.

Topic: Type I vacuum alternative
EPA 608 section: Type I
Error category: REG
Regulatory basis: 40 CFR § 82.156(b)

Question 30

Correct answer: C. Functional: 90%; nonfunctional: 80%

The current rule is 90% with a functioning appliance compressor and 80% when it is not functioning.

• A is incorrect: The percentages are reversed.
• B is incorrect: The rule does not require 100%/90%.
• D is incorrect: Four inches Hg is an alternative vacuum endpoint, not these percentages.

Topic: Type I percentage recovery pairing
EPA 608 section: Type I
Error category: REG
Regulatory basis: 40 CFR § 82.156(b)

Question 31

Correct answer: A. The operating appliance compressor

Operating the appliance compressor moves refrigerant from the low side toward the high side and can assist system-dependent recovery.

• B is incorrect: A disposable cylinder is not the pumping source.
• C is incorrect: Thermostat wiring does not move refrigerant.
• D is incorrect: The cabinet drain is not part of the refrigerant circuit.

Topic: Operating-compressor recovery flow
EPA 608 section: Type I
Error category: PRO

Question 32

Correct answer: B. Add/use low-side refrigerant access so the trapped side can also be recovered.

A failed compressor and capillary restriction can leave refrigerant trapped; using both sides improves removal.

• A is incorrect: Intentional venting is not the proper adjustment.
• C is incorrect: A seized compressor should not be relied on for pumping.
• D is incorrect: Oxygen is unsafe and not a recovery method.

Topic: Failed-compressor two-side recovery scenario
EPA 608 section: Type I
Error category: PRO

Question 33

Correct answer: A. Use controlled warming and, where appropriate, sharply strike or tap the compressor to help release trapped refrigerant.

Controlled heat and the traditional sharp-strike/tapping technique can help release refrigerant from oil and trapped regions.

• B is incorrect: Open-flame heating is unsafe.
• C is incorrect: Oxygen is not a recovery aid and can create a severe hazard.
• D is incorrect: Intentional venting is not the proper recovery method.

Topic: Failed-compressor refrigerant release
EPA 608 section: Type I
Error category: SAF

Question 34

Correct answer: B. A temporary clamp-on access fitting

A solderless piercing valve is a temporary access fitting clamped to tubing.

• A is incorrect: It is not a recovery cylinder.
• C is incorrect: A process stub is a length of tubing, not the piercing valve itself.
• D is incorrect: It is not a pressure-relief device.

Topic: Piercing access fitting
EPA 608 section: Type I
Error category: DEF

Question 35

Correct answer: C. On a capillary tube or badly corroded tubing

Capillary tubing and damaged/corroded sections are poor and unsafe fitting locations.

• A is incorrect: Suitable tubing may be used when compatible with the fitting.
• B is incorrect: Undamaged appropriate tubing can be selected.
• D is incorrect: An approved service location can be appropriate.

Topic: Access-fitting location
EPA 608 section: Type I
Error category: SAF

Question 36

Correct answer: B. Restore/reseal the tubing and leak check it.

The tubing should be properly restored/resealed and checked for leakage.

• A is incorrect: An open puncture would leak refrigerant and admit contaminants.
• C is incorrect: Electrical tape is not a proper refrigerant-circuit repair.
• D is incorrect: Adding refrigerant does not repair a leak.

Topic: Access-fitting removal and resealing
EPA 608 section: Type I
Error category: PRO

Question 37

Correct answer: C. It is a length of tubing provided for refrigerant access and can be resealed after service.

The regulatory definition describes access tubing that can be resealed.

• A is incorrect: A manifold hose is unrelated.
• B is incorrect: A stub is not necessarily a valve.
• D is incorrect: The recovery compressor is a different component.

Topic: Process stub definition
EPA 608 section: Type I
Error category: DEF
Regulatory basis: 40 CFR § 82.152

Question 38

Correct answer: D. Confirm the machine is compatible with the refrigerant and that the recovery cylinder has adequate capacity.

Self-contained recovery still requires refrigerant compatibility, proper cylinder selection/capacity, and normal safety checks.

• A is incorrect: Safety controls should not be disabled.
• B is incorrect: A self-contained machine does not require the appliance compressor to provide the pumping action.
• C is incorrect: Disposable cylinders must not be used as recovery cylinders.

Topic: Self-contained recovery preparation
EPA 608 section: Type I
Error category: SAF

Question 39

Correct answer: D. The refrigerant may be misidentified or noncondensables may be present.

Pressure-temperature information can help identify refrigerant and indicate noncondensables when conditions are appropriate.

• A is incorrect: EPA Type I test topics specifically include pressure-temperature use for identification/noncondensables.
• B is incorrect: The mismatch does not establish charge weight.
• C is incorrect: It does not prove compressor seizure.

Topic: Type I refrigerant identification and noncondensables
EPA 608 section: Type I
Error category: PRO

Question 40

Correct answer: B. A person with appropriate Type I or Universal certification, subject to any applicable apprentice/lab exception

Type I or Universal certification is the appropriate Section 608 credential for small-appliance service.

• A is incorrect: The disposal exception does not authorize ordinary service.
• C is incorrect: Section 609 is for MVAC service.
• D is incorrect: A scrap processor role does not replace technician certification for repair.

Topic: Type I service certification
EPA 608 section: Type I
Error category: REG
Regulatory basis: 40 CFR §§ 82.152, 82.161

Question 41

Correct answer: C. The disposal activity has a technician-certification exception, but refrigerant must still be properly recovered.

Small-appliance disposal is excluded from the technician definition, but safe-disposal recovery requirements remain.

• A is incorrect: Type III is for low-pressure appliances and is not required merely because the appliance is discarded.
• B is incorrect: Disposal does not allow intentional venting.
• D is incorrect: Disposable cylinders are not recovery cylinders.

Topic: Type I disposal certification exception
EPA 608 section: Type I
Error category: REG
Regulatory basis: 40 CFR § 82.152 and safe-disposal requirements

Question 42

Correct answer: A. An appliance sticker that simply says “refrigerant removed”

A sticker alone does not contain the required verification information.

• B is incorrect: A qualifying regular-supplier contract can be used.
• C is incorrect: A properly executed signed statement can serve as verification.
• D is incorrect: The prescribed documentation can be relied upon when properly completed.

Topic: Safe-disposal verification
EPA 608 section: Type I
Error category: REG
Regulatory basis: Current EPA safe-disposal guidance

Question 43

Correct answer: C. The statement is incomplete because the date of recovery is also required.

The prior-recovery verification statement includes name, address, and date of recovery.

• A is incorrect: A sticker does not replace the required verification.
• B is incorrect: The date is part of the required information.
• D is incorrect: Compressor removal does not eliminate safe-disposal responsibilities.

Topic: Safe-disposal signed statement
EPA 608 section: Type I
Error category: REG
Regulatory basis: 40 CFR § 82.155 and current EPA safe-disposal guidance

Question 44

Correct answer: A. The refrigerant line was deliberately cut to make handling easier.

Deliberately cutting a charged line is not an unavoidable prior loss and can constitute improper release.

• B is incorrect: A genuine system failure can be an unavoidable loss.
• C is incorrect: Accidental damage can support an already-lost explanation when properly documented.
• D is incorrect: An accidental rupture can qualify as an unavoidable occurrence.

Topic: Safe-disposal leaked-out distinction
EPA 608 section: Type I
Error category: REG
Regulatory basis: Current EPA safe-disposal requirements

Question 45

Correct answer: D. To document compliance with the prior-recovery verification responsibility

The records document the final processor’s basis for relying on prior recovery.

• A is incorrect: Record retention does not reclaim refrigerant.
• B is incorrect: Compressor condition is not the purpose of those disposal records.
• C is incorrect: The records are not primarily factory-charge documents.

Topic: Disposal records purpose
EPA 608 section: Type I
Error category: REG
Regulatory basis: Current EPA safe-disposal requirements

Question 46

Correct answer: D. Verify that the second appliance also contains compatible R-134a and that the cylinder has adequate capacity.

Refrigerant identity and available cylinder capacity should be confirmed before recovery.

• A is incorrect: Cylinder fill monitoring remains required regardless of compressor condition.
• B is incorrect: Type I classification does not mean different refrigerants are compatible.
• C is incorrect: Air adds noncondensables and does not separate refrigerants safely.

Topic: Type I recovery-cylinder preparation
EPA 608 section: Type I
Error category: SAF

Question 47

Correct answer: C. Refrigerant evaporation is cooling the local tubing/component.

Evaporating refrigerant absorbs heat and can cool surfaces enough for frost to form.

• A is incorrect: Reclamation does not occur merely from evaporation.
• B is incorrect: Frost does not change the appliance certification category.
• D is incorrect: Frost on the appliance does not prove anything about cylinder emptiness.

Topic: Phase-change cooling during recovery
EPA 608 section: Type I
Error category: DEF

Question 48

Correct answer: A. It is the maximum refrigerant charge, but the factory-manufactured, factory-charged, and hermetically sealed conditions must also be met.

Five pounds or less is one of four required small-appliance conditions.

• B is incorrect: The charge amount alone is not enough.
• C is incorrect: Cylinder pressure is not limited by a 5-lb value.
• D is incorrect: The oil-change provision uses 5 psig, a different unit and concept.

Topic: Five-pound small-appliance condition
EPA 608 section: Type I
Error category: DIST
Regulatory basis: 40 CFR § 82.152

Question 49

Correct answer: D. Leak check and evacuate/dehydrate the repaired circuit.

After repair, the circuit should be leak checked and evacuated/dehydrated before proper recharge.

• A is incorrect: Recovery before repair does not remove the need to evacuate air and moisture afterward.
• B is incorrect: Covered refrigerant should not be intentionally vented with nitrogen.
• C is incorrect: Temporary solderless access fittings should not be left as the permanent repair.

Topic: Post-repair Type I service sequence
EPA 608 section: Type I
Error category: PRO

Question 50

Correct answer: A. Use low-loss fittings and follow proper hose-clearing procedures.

Low-loss fittings and proper hose management reduce refrigerant trapped and released at disconnect.

• B is incorrect: Liquid-filled hoses can release more refrigerant.
• C is incorrect: Cutting hoses is unsafe and unnecessary.
• D is incorrect: Opening hoses to atmosphere intentionally releases refrigerant.

Topic: Low-loss Type I service practice
EPA 608 section: Type I
Error category: PRO

Type II Answers — Questions 51–75

Question 51

Correct answer: D. 170 to 355 psia

170 to 355 psia is the current high-pressure range.

• A is incorrect: Below 45 psia is low pressure.
• B is incorrect: 45 to 170 psia is medium pressure.
• C is incorrect: Very-high classification is not defined as only above 500 psia.

Topic: High-pressure classification range
EPA 608 section: Type II
Error category: CLS
Regulatory basis: 40 CFR § 82.152

Question 52

Correct answer: A. Type II

Type II includes medium-, high-, and very-high-pressure appliances, subject to specified exclusions.

• B is incorrect: Type I applies to small appliances.
• C is incorrect: Type III applies to low-pressure appliances.
• D is incorrect: Section 609 addresses MVAC service.

Topic: Type II scope includes medium pressure
EPA 608 section: Type II
Error category: CLS
Regulatory basis: 40 CFR § 82.161

Question 53

Correct answer: C. Type II

A high-pressure stationary walk-in is Type II.

• A is incorrect: A field-assembled walk-in is not a Type I small appliance.
• B is incorrect: Type III is for low-pressure appliances.
• D is incorrect: Section 609 is for MVAC service.

Topic: Type II equipment classification
EPA 608 section: Type II
Error category: CLS

Question 54

Correct answer: A. Oil traces near a refrigerant connection

Refrigerant leaks often carry oil, so oil traces can identify areas requiring leak testing.

• B is incorrect: A clean label does not indicate refrigerant leakage.
• C is incorrect: A level pad is not a refrigerant leak sign.
• D is incorrect: A normal thermostat display does not locate a leak.

Topic: High-pressure leak indicators
EPA 608 section: Type II
Error category: PRO

Question 55

Correct answer: B. Leak test the repaired area using an appropriate method.

Leak testing before full charging confirms the repair and reduces avoidable refrigerant loss.

• A is incorrect: Appearance alone does not prove leak tightness.
• C is incorrect: Charging a leaking system wastes refrigerant and venting is prohibited.
• D is incorrect: Oxygen is not an appropriate refrigeration leak-test gas.

Topic: Leak check before charging
EPA 608 section: Type II
Error category: PRO

Question 56

Correct answer: D. Commercial refrigeration 20%; industrial process refrigeration 30%

Current Section 608 uses 20% for commercial refrigeration and 30% for industrial process refrigeration; comfort cooling/other qualifying appliances use 10%.

• A is incorrect: The commercial and industrial-process values are reversed.
• B is incorrect: 15% is a legacy value, not the current universal rate.
• C is incorrect: These values are not the current table.

Topic: Current Section 608 leak-rate categories
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.157(c)(2)

Question 57

Correct answer: C. 120 days

When an industrial process shutdown is required, the general period is 120 days.

• A is incorrect: Ten days is associated with follow-up verification timing, not the general shutdown repair period.
• B is incorrect: Thirty days is the general repair period when an industrial process shutdown is not required.
• D is incorrect: One year is associated with retrofit/retirement planning limits under specified conditions, not an automatic repair period.

Topic: Leak-repair timing
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.157(d)

Question 58

Correct answer: D. Within 10 days, or within 10 days after normal operating conditions are reached when applicable

The current rule generally requires follow-up verification within 10 days of the successful initial test or normal operating conditions, as applicable.

• A is incorrect: It necessarily follows a repair and initial verification.
• B is incorrect: Two hundred days is not the verification period.
• C is incorrect: Follow-up verification is part of the repair process, not optional until another leak occurs.

Topic: Leak-repair verification timing
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.157(e)

Question 59

Correct answer: B. Recover bulk liquid from a suitable liquid access point before finishing with vapor.

Liquid-first recovery removes large refrigerant mass rapidly before vapor completion.

• A is incorrect: Vapor-only recovery is slower when bulk liquid is accessible.
• C is incorrect: Torch heating is unsafe and raises cylinder pressure.
• D is incorrect: Trapping liquid makes recovery incomplete.

Topic: Liquid-first recovery
EPA 608 section: Type II
Error category: PRO

Question 60

Correct answer: C. Controlled warming of the appliance

Controlled warming raises refrigerant vapor pressure and can improve recovery flow.

• A is incorrect: Oxygen is not used to boost recovery.
• B is incorrect: Open-flame cylinder heating is unsafe.
• D is incorrect: Smaller hoses increase restriction.

Topic: Appliance warming during recovery
EPA 608 section: Type II
Error category: PRO

Question 61

Correct answer: B. It may still contain refrigerant and must be recovered/evacuated as required.

The isolated compressor can retain refrigerant and must be treated accordingly.

• A is incorrect: Isolation does not remove refrigerant trapped inside the component.
• C is incorrect: Isolation is not reclamation.
• D is incorrect: Opening pressure must meet applicable service-practice requirements.

Topic: Parallel compressor isolation
EPA 608 section: Type II
Error category: PRO

Question 62

Correct answer: B. 4 in. Hg vacuum

All pre-1993 medium-pressure rows require 4 in. Hg vacuum.

• A is incorrect: Zero is not the pre-1993 medium-pressure requirement.
• C is incorrect: Ten inches is the post-1993 medium-pressure <200-lb value.
• D is incorrect: Fifteen inches is the post-1993 medium-pressure ≥200-lb value.

Topic: Pre-1993 medium-pressure evacuation
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.156 Table 1

Question 63

Correct answer: A. 4 in. Hg vacuum

A pre-1993 high-pressure appliance with full charge ≥200 lb requires 4 in. Hg vacuum.

• B is incorrect: Zero applies to high-pressure appliances below 200 lb or very-high-pressure appliances.
• C is incorrect: Ten inches is the post-1993 high-pressure ≥200-lb value.
• D is incorrect: Fifteen inches is the post-1993 medium-pressure ≥200-lb value.

Topic: Pre-1993 high-pressure evacuation
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.156 Table 1

Question 64

Correct answer: B. A medium-pressure appliance with 150 lb

Medium-pressure appliances below 200 lb require 10 in. Hg vacuum with post-1993 equipment.

• A is incorrect: Very-high-pressure appliances require 0 in. Hg vacuum.
• C is incorrect: High-pressure appliances below 200 lb require 0 in. Hg vacuum.
• D is incorrect: Medium-pressure appliances ≥200 lb require 15 in. Hg vacuum.

Topic: Post-1993 Type II evacuation
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.156 Table 1

Question 65

Correct answer: D. Use appropriate self-contained recovery equipment rather than ordinary system-dependent equipment.

Without the permanent pump-out exception, appropriate self-contained recovery equipment is the compliant choice.

• A is incorrect: The restriction applies when the appliance full charge is greater than 15 lb.
• B is incorrect: A vacuum pump is not a substitute for certified refrigerant recovery equipment.
• C is incorrect: Intentional venting is not a way to change the full-charge criterion.

Topic: System-dependent recovery-equipment limit
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.156(e)

Question 66

Correct answer: C. Replacing the compressor

Compressor removal is explicitly major by definition.

• A is incorrect: External insulation replacement does not make the service major.
• B is incorrect: A service cap is not one of the named major components.
• D is incorrect: A mounting bracket is not a major refrigerant-circuit component.

Topic: Major component removal
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.152

Question 67

Correct answer: A. No, because the opening does not exceed 4 in².

The flow area must be more than 4 in² as well as open more than 15 minutes.

• B is incorrect: Both numerical conditions must be met; duration alone is insufficient.
• C is incorrect: Type II classification alone does not make every repair major.
• D is incorrect: The major definition applies across covered appliance categories.

Topic: Major opening-size criterion
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.152

Question 68

Correct answer: C. 0 psig

Medium-, high-, and very-high-pressure appliances can use no higher than 0 psig under the qualifying non-major provision.

• A is incorrect: 5 psig is the special oil-change limit.
• B is incorrect: 10 psig is not the Type II non-major pressure ceiling.
• D is incorrect: 15 in. Hg vacuum is a Table 1 value for a different condition.

Topic: Qualifying non-major opening
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.156(a)(1)(i)

Question 69

Correct answer: D. Not above 0 psig

The leaking component must be taken to the lowest attainable level without substantial contamination, and that level may not exceed 0 psig.

• A is incorrect: The leaking component is not required to reach 15 in. Hg vacuum when the exception applies.
• B is incorrect: 5 psig is the oil-change provision.
• C is incorrect: 10 psig is not the current ceiling for this exception.

Topic: Leaking-component exception
EPA 608 section: Type II
Error category: REG
Regulatory basis: 40 CFR § 82.156(a)(2)

Question 70

Correct answer: A. It is not one of the four named major components; the actual opening size/duration and service conditions must still be evaluated.

Filter-drier replacement is not major solely by name, but the complete definition and service conditions still apply.

• B is incorrect: A filter-drier job could meet the numerical opening criterion depending on circumstances.
• C is incorrect: The major definition names specific components and an opening criterion, not every component.
• D is incorrect: Stationary Type II service is Section 608, not Section 609.

Topic: Filter-drier and major repair
EPA 608 section: Type II
Error category: DIST
Regulatory basis: 40 CFR § 82.152

Question 71

Correct answer: C. Use the indicator manufacturer’s color legend.

The manufacturer’s legend is the correct basis for interpreting the indicator.

• A is incorrect: Color meanings are not universal across all products.
• B is incorrect: Moisture can cause serious system contamination and restrictions.
• D is incorrect: Compressor current does not define sight-glass color meaning.

Topic: Moisture indicator interpretation
EPA 608 section: Type II
Error category: PRO

Question 72

Correct answer: D. It can rapidly create excessive pressure because the compressor is positive displacement.

A positive-displacement compressor can build dangerous pressure against a closed discharge path.

• A is incorrect: Compressor operation does not reclaim refrigerant.
• B is incorrect: A closed discharge tends to raise, not lower, discharge pressure.
• C is incorrect: It does not create an acceptable venting path.

Topic: Closed discharge valve safety
EPA 608 section: Type II
Error category: SAF

Question 73

Correct answer: A. Keep the compressor de-energized and use the external vacuum pump.

The external vacuum pump is the proper evacuation device while the hermetic compressor remains off.

• B is incorrect: Starting under deep vacuum can create electrical arcing/damage risk.
• C is incorrect: Bypassing safety devices increases risk.
• D is incorrect: Oxygen must not be introduced.

Topic: Hermetic compressor vacuum safety
EPA 608 section: Type II
Error category: SAF

Question 74

Correct answer: A. Refrigerant can migrate into the oil, causing dilution and foaming at startup.

A cold crankcase can collect refrigerant in the oil, leading to dilution and foaming on startup.

• B is incorrect: Condenser-water freezing is not the direct crankcase-heater issue.
• C is incorrect: Recovery-cylinder fill is unrelated.
• D is incorrect: Refrigerant safety classification does not change because the heater failed.

Topic: Crankcase heater and migration
EPA 608 section: Type II
Error category: SAF

Question 75

Correct answer: B. Use equipment whose working-pressure ratings and refrigerant compatibility are adequate for the job.

Very-high-pressure service requires recovery equipment, hoses, gauges/manifolds, fittings, and cylinders rated for the expected refrigerant and pressures.

• A is incorrect: Physical fit does not establish a safe pressure rating.
• C is incorrect: Safety controls should not be defeated.
• D is incorrect: Open flame is unsafe and does not correct an inadequate rating.

Topic: Very-high-pressure equipment rating
EPA 608 section: Type II
Error category: SAF

Type III Answers — Questions 76–100

Question 76

Correct answer: A. Type III classification is based on the appliance refrigerant having saturation pressure below 45 psia at 104°F.

Type III applies to low-pressure appliances as defined by refrigerant saturation pressure.

• B is incorrect: A Type II appliance also has a low side.
• C is incorrect: Equipment weight is not the classification basis.
• D is incorrect: An evaporator is a component, not automatically a separate Type III appliance.

Topic: Type III classification versus low side
EPA 608 section: Type III
Error category: CLS
Regulatory basis: 40 CFR §§ 82.152 and 82.161

Question 77

Correct answer: D. The pressure difference can draw air and moisture inward through the leak.

Below atmospheric pressure, the pressure differential can drive air/moisture into the refrigerant circuit.

• A is incorrect: Leaks can pass material according to pressure conditions.
• B is incorrect: Solidification is not the general reason.
• C is incorrect: Purge operation does not automatically seal a physical leak.

Topic: Inward leakage under vacuum
EPA 608 section: Type III
Error category: PRO

Question 78

Correct answer: C. They can increase condenser pressure and reduce heat-transfer performance.

Noncondensables add partial pressure and interfere with normal condensation.

• A is incorrect: Their presence is precisely why purge systems are needed.
• B is incorrect: They do not create a perfect vacuum.
• D is incorrect: They are contaminants, not a purity improvement.

Topic: Noncondensables in low-pressure chillers
EPA 608 section: Type III
Error category: DEF

Question 79

Correct answer: C. Air infiltration causing noncondensables to accumulate

Air entering a low-pressure system creates purge load and noncondensables can raise condensing pressure.

• A is incorrect: Water-box pressure alone does not explain both refrigerant-side symptoms.
• B is incorrect: A tight system would not normally create excessive air infiltration.
• D is incorrect: A stored cylinder does not by itself cause these operating symptoms.

Topic: Purge operation and noncondensables
EPA 608 section: Type III
Error category: PRO

Question 80

Correct answer: B. Its saturation pressure increases as refrigerant temperature rises.

For refrigerant at saturation, raising temperature raises saturation pressure and can reduce the depth of vacuum without adding noncondensables.

• A is incorrect: ODP is not the mechanism controlling system pressure.
• C is incorrect: Heating does not make refrigerant mass disappear.
• D is incorrect: Refrigerant saturation pressure is strongly related to temperature.

Topic: Pressure-temperature basis of low-pressure pressurization
EPA 608 section: Type III
Error category: CAL

Question 81

Correct answer: C. Maintain controlled pressure without exceeding the 10-psig Type III exam maximum.

The traditional exam maximum is 10 psig, so additional pressure beyond what is needed should not exceed it.

• A is incorrect: Pressurizing to 20 psig would exceed the Type III exam maximum.
• B is incorrect: A rupture disc is emergency protection, not a manual test valve.
• D is incorrect: Oxygen should not be introduced.

Topic: Low-pressure leak-test maximum
EPA 608 section: Type III
Error category: SAF

Question 82

Correct answer: B. Place the refrigerant detector probe at the water-box drain opening.

Refrigerant leaking through tubes can collect at the drain, where a detector can be used after draining.

• A is incorrect: Oxygen is unsafe for pressure testing.
• C is incorrect: Refrigerant is not intentionally placed in the water box.
• D is incorrect: Operating the chiller with an open water box is unsafe and not the test method.

Topic: Water-box leak detection
EPA 608 section: Type III
Error category: PRO

Question 83

Correct answer: B. Liquid removal moves a large mass of refrigerant quickly.

Bulk liquid recovery is much faster for mass removal.

• A is incorrect: Vapor recovery is still necessary afterward.
• C is incorrect: Recovery lowers refrigerant inventory and does not intentionally raise pressure.
• D is incorrect: Freeze prevention and water management are still required.

Topic: Liquid-first low-pressure recovery
EPA 608 section: Type III
Error category: PRO

Question 84

Correct answer: C. Recovery-unit condenser

The recovery-unit condenser rejects heat and condenses compressed recovered refrigerant.

• A is incorrect: The chiller water box is not the recovery-machine condenser.
• B is incorrect: A purge unit removes noncondensables.
• D is incorrect: A rupture disc is a safety relief device.

Topic: Recovery-unit condenser
EPA 608 section: Type III
Error category: DEF

Question 85

Correct answer: D. 10 psig

The traditional Type III recovery-unit high-side cutout value is 10 psig.

• A is incorrect: 5 psig is associated with the current special oil-change opening provision, not this recovery-unit cutout.
• B is incorrect: 25 mm Hg absolute, not 25 psig, is the normal low-pressure Table 1 evacuation endpoint.
• C is incorrect: 15 psig is associated with the traditional low-pressure recovery-vessel rupture-disc exam value.

Topic: Low-pressure recovery-unit high-pressure cutout
EPA 608 section: Type III
Error category: SAF

Question 86

Correct answer: D. It applies to the low-pressure recovery vessel, not automatically to every chiller relief device.

The traditional 15-psig value belongs to the recovery vessel and should not be generalized to every chiller.

• A is incorrect: The qualifying non-major opening ceiling is 0 psig.
• B is incorrect: The evacuation endpoint is 25 mm Hg absolute.
• C is incorrect: Oil heating is expressed as 130°F.

Topic: Recovery-vessel rupture-disc value
EPA 608 section: Type III
Error category: DIST

Question 87

Correct answer: A. Stopping required water circulation while refrigerant pressure continues to fall

As refrigerant pressure and saturation temperature fall, stagnant tube water is more vulnerable to freezing.

• B is incorrect: Adequate recovery-condenser cooling supports recovery rather than causing tube freeze.
• C is incorrect: Liquid-first recovery is a normal sequence.
• D is incorrect: Monitoring pressure is a protective practice.

Topic: Freeze prevention during recovery
EPA 608 section: Type III
Error category: SAF

Question 88

Correct answer: C. The water can freeze as pressure and saturation temperature fall.

Water in the refrigerant circuit can freeze during low-pressure recovery and damage tubes/components.

• A is incorrect: Cylinder tare weight is not the central hazard.
• B is incorrect: Water does not become refrigerant.
• D is incorrect: Water does not prevent pressure from changing.

Topic: Water contamination and freeze risk
EPA 608 section: Type III
Error category: SAF

Question 89

Correct answer: B. Water can be drawn into the refrigerant circuit and then freeze as pressure falls.

The pressure difference can pull water through a tube leak, and low saturation temperature can freeze it.

• A is incorrect: A purge unit does not reclaim water from a flooded refrigerant circuit.
• C is incorrect: Oil does not automatically dry.
• D is incorrect: Vacuum can increase inward water movement rather than prevent it.

Topic: Tube leak and water intrusion
EPA 608 section: Type III
Error category: SAF

Question 90

Correct answer: A. Refrigerant can dissolve in the oil and be released as pressure is reduced.

Refrigerant dissolved in oil can come out of solution as pressure falls, causing additional vapor load or rebound.

• B is incorrect: Oil does not automatically destroy refrigerant.
• C is incorrect: Pressure does not become infinite.
• D is incorrect: Refrigerant-oil solubility is a recognized service issue.

Topic: Refrigerant solubility in oil
EPA 608 section: Type III
Error category: PRO

Question 91

Correct answer: D. Drive dissolved refrigerant out of the oil and reduce release during removal.

Heating helps refrigerant leave solution before the oil is removed.

• A is incorrect: Recovery-vessel relief settings are not changed by heating chiller oil.
• B is incorrect: Adding moisture is undesirable.
• C is incorrect: Refrigerant pressure classification does not change because oil is heated.

Topic: Oil heating purpose
EPA 608 section: Type III
Error category: PRO

Question 92

Correct answer: D. Oil-change special opening: no higher than 5 psig; normal low-pressure Table 1 endpoint: 25 mm Hg absolute

The current oil-change special provision uses no higher than 5 psig, while the normal low-pressure Table 1 endpoint is 25 mm Hg absolute.

• A is incorrect: The units and concepts are unrelated.
• B is incorrect: The values are reversed and use different contexts.
• C is incorrect: 15 psig and 130°F are different traditional exam-preparation values, not this pairing.

Topic: Type III value distinctions
EPA 608 section: Type III
Error category: REG
Regulatory basis: 40 CFR § 82.156(a)(1)(iii) and Table 1

Question 93

Correct answer: A. Introduce vapor first, then transition to liquid when conditions permit.

Vapor-first charging raises pressure and saturation temperature before bulk liquid is admitted.

• B is incorrect: Bulk liquid into deep vacuum can flash violently and create severe cooling/freezing risk.
• C is incorrect: A rupture-disc outlet is not a charging connection.
• D is incorrect: Water must be kept out of the refrigerant circuit.

Topic: Vapor-first charging sequence
EPA 608 section: Type III
Error category: PRO

Question 94

Correct answer: C. It is the designated low refrigerant-side charging connection.

The evaporator charging valve is the designated refrigerant charging connection for the Type III procedure.

• A is incorrect: It is separate from the purge exhaust.
• B is incorrect: It is not a water relief valve.
• D is incorrect: It is not on the external recovery vessel.

Topic: Evaporator charging valve
EPA 608 section: Type III
Error category: DEF

Question 95

Correct answer: B. The blend may need to be withdrawn from the source as liquid, while the initial refrigerant entering a deeply evacuated chiller is still managed as vapor.

Source-cylinder phase and the phase initially entering the chiller are separate concerns; a blend can be removed as liquid and then appropriately metered/vaporized.

• A is incorrect: Vapor withdrawal can cause fractionation for some blends.
• C is incorrect: Blend composition remains important.
• D is incorrect: Air introduces noncondensables and moisture.

Topic: Blend handling versus vapor-first charging
EPA 608 section: Type III
Error category: DIST

Question 96

Correct answer: A. 25 mm Hg absolute

Low-pressure appliances require 25 mm Hg absolute in both pre- and post-1993 columns.

• B is incorrect: 4 in. Hg vacuum is not the low-pressure endpoint.
• C is incorrect: 10 in. Hg vacuum is a Type II value.
• D is incorrect: 15 in. Hg vacuum is a Type II value.

Topic: Low-pressure Table 1 date independence
EPA 608 section: Type III
Error category: REG
Regulatory basis: 40 CFR § 82.156 Table 1

Question 97

Correct answer: B. No, low-pressure appliances remain at 25 mm Hg absolute.

The low-pressure row is 25 mm Hg absolute regardless of the 200-lb boundary.

• A is incorrect: 15 in. Hg vacuum is a medium-pressure Type II condition.
• C is incorrect: 0 psig belongs to certain special opening conditions, not the normal Type III table endpoint.
• D is incorrect: The low-pressure endpoint is the same in both recovery-equipment date columns.

Topic: Type III evacuation and 200-lb boundary
EPA 608 section: Type III
Error category: REG
Regulatory basis: 40 CFR § 82.156 Table 1

Question 98

Correct answer: A. Use controlled heat as applicable and only use nitrogen within the conditions allowed by the rule.

The current rule distinguishes low-pressure refrigerants and favors heat, with limited nitrogen use under specified conditions.

• B is incorrect: Unregulated nitrogen is unsafe and the rule places conditions on its use.
• C is incorrect: Oxygen should not be used.
• D is incorrect: Intentional refrigerant venting is not the prescribed method.

Topic: Low-pressure non-major pressurization
EPA 608 section: Type III
Error category: REG
Regulatory basis: 40 CFR § 82.156(a)(1)(ii)

Question 99

Correct answer: D. The refrigerant alarm still matters because the two instruments measure different quantities.

A refrigerant monitor detects refrigerant concentration; an oxygen monitor measures oxygen concentration.

• A is incorrect: Normal oxygen does not prove zero refrigerant concentration.
• B is incorrect: Normal oxygen does not invalidate a refrigerant-specific alarm.
• C is incorrect: The instruments have different sensing purposes.

Topic: Refrigerant versus oxygen monitoring
EPA 608 section: Type III
Error category: SAF

Question 100

Correct answer: A. Stopping the pump does not eliminate static head or trapped pressure, so the water side must still be isolated and depressurized before opening.

Static head and trapped pressure can remain after a pump stops.

• B is incorrect: Pump status alone does not prove zero pressure.
• C is incorrect: Water-side pressure does not prove refrigerant overcharge.
• D is incorrect: Opening must wait until safe isolation/depressurization is verified.

Topic: Water-side static pressure
EPA 608 section: Type III
Error category: SAF

References

Current Regulatory and EPA Sources

• U.S. Environmental Protection Agency, Section 608 Test Topics, reviewed August 14, 2026.
• U.S. Environmental Protection Agency, Section 608 Technician Certification Requirements, reviewed August 14, 2026.
• Electronic Code of Federal Regulations, 40 CFR Part 82, Subpart F, current text reviewed August 14, 2026.
• 40 CFR § 82.152 — Definitions.
• 40 CFR § 82.154 — Prohibitions.
• 40 CFR § 82.155 — Safe disposal of appliances.
• 40 CFR § 82.156 — Proper evacuation of refrigerant from appliances.
• 40 CFR § 82.157 — Appliance maintenance and leak repair.
• 40 CFR § 82.161 — Technician certification.