6.11 - Practice Questions

Module: Safety Leak Detection Shipping and Safe Disposal
Covers: Sections 6.1–6.10
Question type: Original EPA 608-style multiple-choice practice
Technical and regulatory verification basis: Module 6 content reviewed and current regulatory/safety items verified in Sections 6.1–6.9 through August 10, 2026
Answers: See 6.12 - Answers and Explanations.md

Instructions

• Select the single best answer for each question.
• Complete the entire set without notes or external references when using it as a cumulative assessment.
• Record a confidence code for every answer:
  • C3 — certain and can explain the reason.
  • C2 — probably correct but not fully certain.
  • C1 — guessed between two or more choices.
  • C0 — no reliable basis for the answer.
• Enter every incorrect, C1, and C0 response in the project error log.
• Review the detailed explanations only after completing all questions.
• A correct guess is not considered mastered.
• Pay close attention to words such as not, except, first, before, after, manufacturer, refrigerant-specific, downstream, location, verification, final processor, and required.
• These are original project questions. They are not actual EPA examination questions and are not represented as questions from any certifying provider.

Practice Recor

• Date:
• Time started:
• Time completed:
• Testing condition: Closed-book
• Question set: Module 6 Practice Set
• Correct answers: ___ / 35
• Low-confidence answers (C0–C1):
• Open P1 errors after review:
• Primary weak topic:

Coverage

Practice Questions

Question 1

A technician is disconnecting a service hose where liquid refrigerant could spray toward the face. Which statement best describes appropriate eye and face protection?

A. A face shield alone always replaces primary eye protection.

B. Appropriate primary eye protection should be used, with a face shield added when the task requires additional face protection.

C. Eye protection is unnecessary if gloves are being worn.

D. Ordinary sunglasses provide the same protection as refrigerant-service PPE.

Question 2

Liquid refrigerant contacts a technician’s hand and the tissue becomes frozen. Which first-response action is most appropriate?

A. Rub the tissue vigorously to restore circulation.

B. Flush the frozen tissue with hot water until sensation returns.

C. Avoid rubbing the frozen tissue and obtain prompt medical attention while following the refrigerant SDS.

D. Break any clothing frozen to the tissue away immediately.

Question 3

Which Safety Data Sheet section is most directly associated with exposure controls and personal protection?

A. Section 2

B. Section 4

C. Section 8

D. Section 10

Question 4

Which statement about refrigerant-service gloves is most accurate?

A. One glove material is universally correct for every refrigerant and service task.

B. Gloves are required only when handling flammable refrigerants.

C. Glove selection should consider the refrigerant, cold-contact hazard, task, duration, and SDS/manufacturer guidance.

D. Thin fabric gloves are always preferred because they improve dexterity.

Question 5

Under the OSHA definition used in this module, an atmosphere is oxygen-deficient when oxygen concentration is:

A. Below 25.0% by volume.

B. Below 21.0% by volume.

C. Below 19.5% by volume.

D. Below 10.0% by volume only.

Question 6

Which statement best describes refrigerant accumulation after a large release?

A. Every refrigerant always forms a perfectly separated layer at floor level.

B. Many common refrigerant vapors can create higher concentrations in low areas, but actual behavior depends on the refrigerant and room airflow.

C. Refrigerant vapor always rises immediately to the ceiling.

D. Vapor density is irrelevant to refrigerant-release safety.

Question 7

Why is an ordinary air-purifying respirator not an adequate solution for an oxygen-deficient atmosphere?

A. It removes oxygen from the air.

B. It supplies too much oxygen.

C. It filters or treats ambient air but does not provide the missing oxygen.

D. It can be used only with liquid refrigerant.

Question 8

Which statement about a refrigeration machinery room and OSHA confined-space requirements is most accurate?

A. Every machinery room is automatically a permit-required confined space.

B. A machinery room can never contain a confined space.

C. The actual confined-space definition must be applied; a normal machinery room may not qualify, while a pit or vault associated with it may qualify.

D. Any room containing refrigerant is automatically a confined space.

Question 9

Which gas should normally be used for refrigeration-system pressure testing when the manufacturer permits the procedure?

A. Oxygen

B. Compressed air

C. Dry nitrogen

D. Acetylene

Question 10

Why should refrigerants be kept away from open flames and excessively hot surfaces?

A. High temperature can cause refrigerant decomposition and create hazardous reaction products.

B. Heat always converts every refrigerant into harmless nitrogen.

C. Hot surfaces permanently eliminate refrigerant flammability.

D. Refrigerant pressure always falls to zero when heated.

Question 11

Which statement about phosgene is most accurate?

A. It is the only decomposition product produced by every refrigerant.

B. It can be produced under some chlorine-containing halocarbon decomposition conditions, but it is not a universal product of every refrigerant.

C. It is the normal lubricant used with A2L refrigerants.

D. It is intentionally added to refrigerants to improve leak detection.

Question 12

A technician is preparing to service an A2L refrigerant system. Which statement is correct?

A. A2L means the refrigerant is completely nonflammable.

B. Ignition-source control is unnecessary because the toxicity class is A.

C. The technician should use refrigerant-compatible tools and follow the applicable ignition-control, ventilation, code, and manufacturer requirements.

D. A2L service always permits use of an open flame for leak detection.

Question 13

In an ASHRAE refrigerant safety designation such as A2L, what does the letter A indicate?

A. High operating pressure

B. Lower toxicity classification

C. Higher flammability classification

D. Zero global-warming potential

Question 14

Which statement best distinguishes flammability Class 2L from Class 2?

A. Class 2L is a lower-flammability category that also includes a low-burning-velocity criterion.

B. Class 2L means there is no flame propagation under any condition.

C. Class 2L is the higher-toxicity category.

D. Class 2L identifies refrigerants used only in low-pressure chillers.

Question 15

Which description correctly interprets an A3 refrigerant safety group?

A. Lower toxicity and higher flammability

B. Higher toxicity and no flame propagation

C. Lower toxicity and no flame propagation

D. Higher toxicity and lower flammability with low burning velocity

Question 16

Which statement about a refrigerant’s ASHRAE safety group is correct?

A. It directly gives the refrigerant’s ozone-depletion potential.

B. It directly determines whether the appliance is Type I, Type II, or Type III.

C. It combines toxicity and flammability information but is separate from ODP, GWP, and Section 608 appliance pressure classification.

D. It is the same classification used by DOT for hazardous-material transportation.

Question 17

Which sequence best represents the safe generic nitrogen pressure-test arrangement taught in this module?

A. Nitrogen cylinder → refrigeration system → regulator → relief valve

B. Nitrogen cylinder → pressure regulator → downstream relief protection → manifold/service connection → refrigeration system

C. Compressed-air line → relief valve → manifold → refrigeration system

D. Oxygen cylinder → regulator → manifold → refrigeration system

Question 18

What should determine the maximum nitrogen pressure used for a refrigeration-system pressure test?

A. The highest pressure the nitrogen cylinder can supply

B. One universal EPA test pressure for all appliances

C. The manufacturer-specified test procedure and the rating of the weakest component exposed to the test

D. The color of the manifold gauge hoses

Question 19

After the correct standing-test pressure has been established, why should the nitrogen supply normally be isolated from the test volume?

A. To prevent continuing nitrogen flow from masking leakage or changing the observed pressure

B. To make the nitrogen chemically react with the refrigerant oil

C. To lower the cylinder pressure to atmospheric pressure

D. To convert the system from positive pressure to deep vacuum

Question 20

A sealed system under a nitrogen standing test shows a moderate pressure decrease while the equipment temperature also decreases substantially. What is the best conclusion?

A. The pressure change proves a refrigerant leak without further investigation.

B. Temperature change can contribute to the pressure decrease, so the result should be interpreted with temperature and additional leak evidence.

C. Nitrogen pressure cannot change with temperature.

D. The technician should immediately raise the pressure above the manufacturer limit.

Question 21

A technician finds oily residue around a refrigerant-line fitting. What is the best interpretation?

A. The oil proves an active refrigerant leak is occurring at that moment.

B. The oil is a useful clue to a possible leak location and should be verified with an appropriate leak-detection method.

C. The oil proves the system is overcharged.

D. The oil proves that the refrigerant is an A3 refrigerant.

Question 22

Which method is especially useful for pinpointing an accessible leak in a component that is under positive pressure?

A. Bubble / leak-detection solution

B. Charging chart only

C. Receiver-level observation only

D. Vacuum gauge only

Question 23

Why must an electronic refrigerant leak detector be checked for compatibility with the refrigerant being tested?

A. Every detector responds equally to every refrigerant.

B. Different detector sensors and technologies are designed for different refrigerants or gas groups.

C. Detector compatibility matters only for low-pressure chillers.

D. Refrigerant identity affects only the hose color, not the detector.

Question 24

A refrigeration system has been properly recovered and now contains only dry nitrogen at the approved test pressure. Which method can locate a leak without requiring refrigerant to be present?

A. A halogenated-refrigerant electronic detector that senses only refrigerant

B. Bubble solution or an appropriate ultrasonic detector

C. A pressure-temperature chart only

D. A sight glass only

Question 25

After a system is evacuated and isolated from the vacuum pump, the micron reading rises. Which conclusion is most accurate?

A. The exact leak location has been identified.

B. A leak is one possible cause, but moisture, outgassing, refrigerant in oil, or service-tool leakage can also cause the rise.

C. The system is definitely leak-free.

D. The vacuum-decay result proves the compressor shaft seal is leaking.

Question 26

Which statement correctly distinguishes the main machinery-room safety functions?

A. The detector removes refrigerant, the alarm repairs the leak, and the fan measures oxygen.

B. The detector senses an abnormal refrigerant concentration, the alarm warns people, and ventilation removes or dilutes contaminated air.

C. The alarm and detector are the same device by definition and ventilation is unnecessary.

D. Emergency shutdown proves the atmosphere is immediately safe.

Question 27

Why is machinery-room alarm indication outside an entrance important?

A. It allows a person to receive warning before entering a potentially unsafe room.

B. It eliminates the need for any refrigerant detector inside the room.

C. It guarantees that the refrigerant leak has already stopped.

D. It allows untrained personnel to enter and reset the alarm.

Question 28

An older study guide gives one fixed refrigerant-alarm setpoint and one fixed detector height for every machinery room. What is the best current approach?

A. Apply the old values to every refrigerant because machinery-room rules never change.

B. Use the value for the largest refrigerant charge regardless of refrigerant type.

C. Verify the applicable current code/standard, refrigerant properties, equipment listing, AHJ requirements, and manufacturer instructions.

D. Ignore all alarm and detector requirements because they are not part of safety design.

Question 29

Which statement best distinguishes package labels, vehicle placards, and shipping papers?

A. They are three names for the same document.

B. A hazard label is generally placed on the package, a placard is a larger vehicle/container hazard display when required, and a shipping paper describes the hazardous material when required.

C. A placard is placed only on the refrigerant cylinder valve.

D. Shipping papers are used only to record refrigeration-system pressures.

Question 30

Which statement best describes cylinder securement during normal HVAC service-vehicle transportation?

A. A cylinder may roll freely if the cargo compartment is closed.

B. The cylinder should be securely restrained against shifting, overturning, or ejection; upright and secured is the preferred normal HVAC practice, although applicable federal Class 2 rules can permit other secure orientations.

C. The valve handle should be used as the primary tiedown point.

D. Horizontal transport is always prohibited by federal law for every Class 2 cylinder.

Question 31

Which statement about refrigerant-cylinder heat exposure is most accurate?

A. Heating a cylinder reduces its internal pressure.

B. A torch is an acceptable way to increase refrigerant flow from a cylinder.

C. Increasing temperature can increase cylinder pressure, so the cylinder should be protected from flame and excessive heat.

D. The DOT 55°C / 131°F cylinder criterion is the recommended storage temperature for every refrigerant cylinder.

Question 32

A residential split-system air conditioner is being permanently removed and dismantled at the job site. What should occur before the refrigerant circuit is cut or opened for disposal?

A. Recover the refrigerant according to the applicable Section 608 service-practice requirements.

B. Apply a disposal sticker and cut the tubing.

C. Send the charged equipment to a scrap facility and let the final processor recover it after the lines are cut.

D. Add nitrogen until the refrigerant is forced to atmosphere.

Question 33

A household refrigerator reaches the final processor with its refrigerant circuit intact. Under the safe-disposal framework, what are the final processor’s two basic compliance paths?

A. Recover any remaining refrigerant or verify that the refrigerant was properly recovered before delivery.

B. Vent the refrigerant or store the appliance indefinitely.

C. Apply a sticker or paint the compressor.

D. Require Universal certification from every homeowner or refuse all household appliances.

Question 34

A refrigerator arrives at a final processor after another person properly recovered the refrigerant. Which statement best describes current federal verification?

A. A sticker reading “refrigerant removed” is sufficient by itself.

B. The required signed statement includes the name and address of the person who recovered the refrigerant and the date of recovery; a qualifying supplier contract can be used where the rule permits it.

C. Only the compressor serial number is required.

D. Verification is unnecessary whenever the appliance feels empty.

Question 35

Which pair of current disposal recordkeeping statements is correct?

A. Final processors keep qualifying signed statements/contracts for 3 years, and technicians performing disposal recovery from appliances with full charges greater than 5 lb and less than 50 lb keep the required disposal-recovery records for 3 years.

B. Final processors keep stickers for 30 days, and technicians keep records only when the charge exceeds 100 lb.

C. Final processors have no recordkeeping duty, and technicians must keep all disposal records permanently.

D. Both requirements apply only to disposable refrigerant cylinders beginning in 2028.

Answers and detailed explanations are intentionally kept in the separate file 6.12 - Answers and Explanations.md so the questions can be completed without seeing the solutions.