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Cryogenic Compressed Gases

Picture of nitrogen cylinders

Cryogenic liquids and their boil-off vapors rapidly freeze human tissue and cause embrittlement of many common materials, which may crack or fracture under stress. All cryogenic liquids produce large volumes of gas when they vaporize and may create oxygen-deficient conditions.

The quantities of cyrogenic hydrogen or oxygen count against the quantities of flammable or oxidyzing gases respectively that you can have on hand in your area. The quantities that can be stored and used on the floor of a building or within a control area is strictly regulated by the VSFPC, and the allowable quantities decrease for every story above ground level. 

Examples

  • Liquid oxygen
  • Hydrogen
  • Nitrogen
  • Argon
  • Helium
  • Liquid neon

Precautions

  • Transfer operations of cryogenic liquids must be conducted slowly to minimize boiling and splashing. Use appropriate personal protective equipment when transferring cryogenic liquids, including insulated gloves, goggles, and a face shield. 
  • In the event of skin contact with a cryogenic liquid, do not rub the skin. Place the affected part in a warm water bath.
  • Use only equipment, valves, and containers designed for the intended product, service, pressure, and temperature.
  • Inspect the containers for loss of insulating vacuum. If the outside of the jacket on a container is cold or has frost spots, some vacuum has been lost. Empty the contents into another cryogenic container and remove the damaged unit from service. Repairs should only be made by the manufacturer of the container or an authorized service provider.
  • Excessive ice build-up (especially beneath the vaporizer or tank) could result in the discharge of excessively cold gas, or structural damage to the cryogenic container and surroundings.
  • All cryogenic systems, including piping, must be equipped with pressure relief devices to prevent excessive pressure build-up.
  • Do not use open flames or direct intense heat sources to thaw frozen equipment. Hot air, steam, or water can be used to thaw frozen equipment. Do not use water to thaw liquid helium equipment.
  • Order the smallest sized cylinder you can that will support your research, and do not purchase and store spare cylinders.