1. Safe Handling and Use of Liquid Nitrogen
Safety and Compliance

2. Nitrogen gas can cause asphyxiation
In closed areas excessive amounts of nitrogen gas reduce the concentration of oxygen
Nitrogen gas is colorless, odorless, and tasteless
It can’t be detected by human senses and will be breathed as if it were air
The cloudy vapor that appears when liquid nitrogen is exposed to the air is condensed moisture, not the gas itself.

3. Handling Liquid Nitrogen
Avoid prolonged breathing of cryogenic liquid vapors
Avoid rough handling of liquid containers
Use only containers specially designed to hold liquid nitrogen (example Dewars)

4. Dewars

5. Precautions
Nitrogen can spatter (possibly in eyes or to exposed skin) while poured
Flying chunks of frozen objects could cause eye injury
Wear goggles or face shields (Not safety glasses) whenever pouring or dumping nitrogen
Use a cryogenic glove and/ or tongs to handle any objects going into or out of a liquid nitrogen container

6. Personal Protective Equipment

7. Emergencies
If liquid is splashed into eyes, flush with water for 15 minutes and seek immediate medical attention
Skin contact may cause frostbite and burns. Soak affected part in tepid water and seek immediate medical attention
Skin or eye contact is a medical emergency
Extremely low temperature can freeze skin rapidly

8. Refilling Dewars in Laboratories
Make sure there is good ventilation (open a door if you are in a small room)
Use Dewars that are rated for liquid nitrogen
Wear required personal protective equipment
Lab coat with sleeves pulled over cuffs of cryogenic gloves
Closed toe shoes
Chemical splash goggles or full face shield

9. Refilling Dewars in Laboratories
Do not overfill containers
Filling above the bottom of the neck tube or specified maximum level can result in overflow
If liquid nitrogen spills onto the floor it will damage the surface and cause the floor to crack

10. Dispensing Liquid Nitrogen from Storage Tanks
Container must be rated for liquid nitrogen
Dewars must have handles or wheels
Person filling Dewar must be in constant attendance during filling (Never leave unattended)
To prevent splashing, place filling hose at or below mouth of the receiving Dewar

12. Transporting Liquid Nitrogen between Labs
Never transport in a open container
Wear or carry required PPE
Do not use carts or Dewars with unstable wheels
If carrying Dewar make sure it is your only load
Carry Dewar far away from your face and body using good ergonomics
Watch your surroundings for other people who may run into or bump you