1.      Process

Use of liquid nitrogen in a laboratory environment.

2.      Physical Hazards

• Simple asphyxiant
• Non-toxic but may cause suffocation by displacing air
• Causes severe frostbite

3.      Health Hazards

• Freezes tissue
• Causes severe cryogenic burns to eyes and skin

4.      Personal Protective Equipment

EYE PROTECTION

·          Safety glasses/goggles and face shields shall be worn during operations in which liquid nitrogen is being poured from a large container to a Dewar or other small container.

·          Contact lenses shall not be worn if the potential exists for liquid nitrogen exposure.

HAND PROTECTION

·          Loose fitting thermal insulated or leather gloves are recommended.

      BODY PROTECTION

·          Long sleeved shirts and trousers without cuffs are recommended.

·          An impervious full length apron should be worn when transferring liquid nitrogen.  

5.   Handling and Storage

·         Store and use with adequate ventilation.

·         Do not store in a confined space.

·         Some metals such as carbon steel may become brittle at low temperatures and easily fracture.

·         Never allow any unprotected part of body to touch un-insulated vessel.

·         Never place liquid nitrogen in a sealed container or any object that could cause entrapment of the gas.

·         Never mix liquid nitrogen with water or ice or pour it down the sink. Ice can solidify around it, trapping gas at high pressure.

6.  Spill and Leak Procedures

• For small spill, do no attempt to “soak up”. It will become gaseous in a short period of time and dissipate.
• For large spills, liquid nitrogen can quickly displace the oxygen inside a lab. Leave area immediately and contact EH&S at 716-1221 for further instructions.
• If Dewar or large liquid container is leaking, take to outside and let it vent. EH&S will advise on safe transportation to outside.