Use of Commercial Cryogenic Exam

FDNY G79 Supervision of Storage, Handling & Use of Commercial Cryogenic Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the minimum temperature at which a cryogenic liquid is

defined?

A. –50°F

B. –130°F

C. –195°F

D. –300°F

Because NFPA and FDNY define cryogenic liquids as substances with boiling points below –130°F at 14.7 psi.

• Cryogenic liquids stored in containers must be protected from: 1 / 4

• Rain
• Excessive heat
• Sunlight
• Dust

Excessive heat can accelerate pressure buildup inside cryogenic containers.

• Which gas is commonly stored as a commercial cryogenic?
• Carbon monoxide
• Liquid nitrogen
• Propane
• Helium gas

Liquid nitrogen is widely stored and used as a cryogenic in commercial operations.

• What primary hazard is associated with oxygen-enriched atmospheres

from cryogenic leaks?

• Electrical short circuit
• Fire and explosion risk
• Equipment corrosion
• Noise amplification

Oxygen-enriched environments greatly increase flammability of surrounding materials. 2 / 4

• What PPE is required when handling cryogenic liquids?
• Rubber sandals
• Leather gloves
• Insulated cryogenic gloves
• Nitrile exam gloves

Cryogenic gloves protect from extreme cold and frostbite.

6. Cryogenic containers must always be:

• Stored horizontally
• Stored upright
• Stored upside down
• Stored at a 45° angle

Cryogenic cylinders are designed to vent gas properly only in an upright position.

• Which cryogenic gas can displace oxygen and pose an asphyxiation

hazard?

• Oxygen
• Nitrogen
• Ozone
• Hydrogen peroxide 3 / 4

Nitrogen gas is inert and can reduce oxygen levels, posing silent suffocation hazards.

• What is required on all cryogenic storage containers?
• Color coding only
• Hazard identification label
• Company logo
• Serial number

Proper hazard labeling identifies stored contents and safety risks.

9. The expansion rate of liquid nitrogen when vaporized is approximately:

• 5x
• 10x
• 700x
• 3000x

Liquid-to-gas expansion ratios of cryogenics are extremely high, liquid

nitrogen ~700:1.

10. Refrigeration-induced condensation can cause:

• Radiation burns
• Ice buildup and valve blockage
• / 4