SAFETY AND THE USE OF CRYOGENIC LIQUIDS - GUIDANCE

1. Protective Clothing
   

   Personal protective equipment (PPE) must be worn when handling cryogens. However, it is only there to prevent against accidental spillage, splashes, contact with cold surfaces and explosion risks.
   
   PPE IS NOT DESIGNED TO WITHSTAND IMMERSION IN OR PROLONGED CONTACT WITH CRYOGENIC LIQUIDS!
   
   The following equipment must be worn when handling cryogenic materials:
   
   Face shield - protect the users face and eyes against splashes
   
   Gloves - must conform to BS EN 511 (Cold Protection). The gloves should either have been specifically designed for cryogenic handling with ribbed cuffs to prevent splashing into the glove or be loose fitting gauntlets that can easily be removed. The material should be rough to give good grip while handling and not increase the chance of spillage.
   
   Aprons/Overalls - avoid woven materials if possible, if they are used it is essential to ensure they do not become saturated with cold liquid. Fastenings should be at the side or back and there should be no pockets that liquid could get trapped in.
   
   Shoes - should be top-sealed. Never wear boots open from top helping flow of liquid inside the boots or open sandals, which offer no protection in the event of spillage.
   
   General - Sleeves and trousers should be worn outside gloves and boots. All metallic jewellery should be removed to prevent liquid becoming trapped under them.
   

2. Tips on handling cryogenic liquids - DO IT WITH CARE!
   
   • Ensure the vessel is dry and pour cryogenic liquids slowly into the receiving vessel to minimise splashing, spillage and thermal shock to the vessel;
   • Use tongs when placing objects into or removing them from cryogenic liquids
   • Avoid use of wide-necked, shallow vessels to prevent excessive evaporation and the possibility of oxygen enrichment
   • Whenever removing cryogenic liquids from pressurised vacuum insulated vessels (PVIVs) carry out a safety check.
   • Use an appropriate rod for checking the level of the cryogenic liquid in a dewar
   • When removing cell-line cages from storage use a hook to locate the handle and raise the cage
   • Never overfill dewars

   Disposal
   
   Care needs to be taken when disposing of cryogenic liquids
   
   DO NOT pour cryogenic liquids down the sink - they will crack waste pipes causing potentially dangerous leaks
   
   DO NOT store cryogenic substances or allow them to vaporise in enclosed areas, including:
   
   Fridges, Cold Rooms, Sealed Rooms and Basements

   DO ensure that the area in which the cryogenic liquid is left to vaporise is well ventilated