Working with Liquid Nitrogen

Hazardous Chemicals: Liquid nitrogen, boiling temperature 77 K (-196 C).

Protective Equipment: Leather gloves and eye goggles.

Special Handling Procedures: Liquid nitrogen is transferred from low pressure (22 psi) storage dewars into smaller dewars and used to cool reaction flasks or fill vacuum traps.

Spill and Accident Procedures: Small liquid nitrogen spills onto the floor will quickly evaporate. Objects, floor tiles, etc, can be damaged by prolonged exposure to liquid nitrogen at 77K. It can cause by burns from contact with liquid or cold gas, or from contact with objects cooled by the cryogen. A large accidental release of liquid nitrogen will very quickly generate a large volume of cold gas which will displace air from the room. The laboratory should be evacuated until the oxygen level is observed to be at a safe level.