Cryogenic liquids will cause severe burns or frostbite if they contact the skin. Handling uninsulated piping carrying these liquids can also cause burns. Liquid trapped and held against the skin by porous gloves or other clothing can cause particularly severe frostbite. Follow these precautions:

  • Ventilate the operating area.
  • Do not breathe the vapor.
  • Do not catch and confine the bleedoff in a closed container.
  • Check all strainers periodically for blockage.
  • If unusual noises are heard, shut the system down immediately.
  • Vent all lines immediately after shutdown.
  • Allow cryogenic piping or components to warm before repair or disassembly.
  • Be sure all repairs are made with clean spare parts.
  • Keep hands, gloves, and tools clean while handling parts.
  • Do not tighten or disconnect a fitting under pressure.
  • Wear loose-fitting gloves.


Special safety precautions must be taken in addition to those followed for nitrogen service. Oxygen may cause violent explosions when exposed to combustible material, particularly hydrocarbons.

All parts of the system in contact with oxygen must be kept scrupulously clean of oil, grease, petroleum solvent, asphalt, paint, or other combustible materials. Do not use rubber or leather packings, gaskets or hoses.

When repairs are necessary, vent piping, drain liquid oxygen, and purge with oil-free nitrogen before welding or brazing. All spare parts must be certified as CLEAN FOR OXYGEN SERVICE.