ABC of Safety in the Biological Sciences

 

 

CRYOGENIC LIQUIDS
(Carbon Dioxide, Liquid Nitrogen, Liquid Oxygen)

Safe handling of cryogenic liquids requires a knowledge of their properties and a common sense approach to precautions and procedures. Before using any cryogenic fluid ensure the laboratory has the necessary safety facilities (see below) should any spill occur, and that all staff are adequately trained in the hazards, handling and use of that fluid. Hazard data sheets must be obtained on all cryogenic liquids used.

The following are some general points related to the safe handling of cryogenic fluids.

  • Use only approved containers for storage and transport.
  • Transfer fluid using manufacturer approved pumps, either electric or pressure.
  • Completely empty liquid oxygen and nitrogen periodically to avoid accumulation of hydrocarbon gases from the atmosphere.
  • Ensure adequate ventilation when handling these liquids.
  • Never allow liquid oxygen to mix with flammable material as a high potential hazard will result.
  • Handle cryogenic fluids carefully as burns may result.
  • Use adequate personal protection including face mask or goggles, asbestos or leather gloves, laboratory coat, footwear with covered toes (slip­on shoes acceptable ­ easily removed).
  • Perform any technique slowly as boiling and splashing will occur when placing hot object in cold fluid.
  • Use tongs to remove objects from storage.
  • Large vessels should be transported on trolleys designed to transport cryogenic liquids in safety.
  • Storage containers must be constructed of low temperature resistant material.

This list is by no means comprehensive ­ always obtain specific information on the particular cryogenic fluid intended for use.

Reference
Australian Standards 2243 (1982)
Safety in Laboratories, Part 2
North Sydney, Australia.

Bretherick, L. (1986)
Hazards in the Chemical Laboratory, 4th Edition.
Royal Chemical Society, London.

Commonwealth Industrial Gases (1988)
Safety Precautions for Handling Cryogenic Liquids.
C.I.G., 46 Kippax Street, Surrey Hills, N.S.W. 2010, Australia.

 

 

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