Liquid Nitrogen and Cryogenics Training Program

Prepared by: Environmental Health and Safety

Potential HazardsHealth:

• Vapors may cause dizziness or asphyxiation without warning.

• Vapors from liquefied gas are initially more dense than air and spread along ground.

• Contact with gas or liquefied gas may cause burns, severe injury, and/or frostbite.

Public Safety• Immediately call emergency personnel in the

event of a large spill or leak. 9-1-1 from campus phone or 438-8631 for ISUPD dispatcher

• Isolate large spills or leaks for at least 100 meters in all directions.

• Keep unauthorized personnel away.• Stay upwind.• Keep out of low areas.• Ventilate closed spaces before entering.

Container Requirements• Closed container with

a loose fitting top that allows venting.

• Use only vessels approved to contain liquid nitrogen.

• Vessel must have carrying handles or be on wheels.

Potential HazardsExplosion:

• Liquid Nitrogen must be transported and stored in an appropriate container containing pressure relief devices.

• Otherwise, when the pressure builds up,

1. the stopper could be "rocketed out"

2. or worse, the container could explode

Appropriate Containers

Examples of acceptable cryogenic Dewars:

Inappropriate Containers

• DO NOT use open, un-insulated or glass containers!

Liquid Nitrogen Tank• Located off loading dock

at Science Lab Building• Key can be checked out

at the Chemistry storeroom.

• Only trained personnel should dispense Liquid Nitrogen.

• Enter through South East gate.

Valve Location

Liquid Nitrogen Tank• Do NOT touch any

of the valves on the North side of the tank.

• Do NOT enter through the North gate.

DO NOT touch!

Protective Clothing

• Always wear thermal protective clothing when handling refrigerated/cryogenic liquids or solids.

• It is required you wear a full face shield over safety glasses, loose fitting gauntlet gloves, long sleeve shirts, full-length trousers without cuffs, and fully enclosed shoes.

Fill Hose

• The liquid Nitrogen is released through this hose from the outside tank.

Fill Hose

• The liquid Nitrogen is released through this hose from the large inside dewar.

Procedures:Step 1: Fill Hose

• Insert and hold the fill hose into the appropriate container or into the funnel.

Procedures:Step 2: Open/Close Valve

• Open valve slowly to begin filling. • Close valve tightly after filling.

Valve

Valve

Safe Handling• Always wear personal

protective equipment while handling liquid nitrogen.

• Always use Liquid Nitrogen in a well ventilated area.

• Use a loose-fitting stopper or lid that allows venting of the boil off.

• If using a funnel, use caution not to overfill the container.

Safe HandlingContinued

• Only transport liquid nitrogen in the freight elevator with no other occupants present.

• Only use containers that have been designed specifically for cryogenic liquids.

• Do not store in a confined space.

• Do not store at temperatures above 125°F.

References

• DOT Emergency Response Guide• CAMEO Chemicals Datasheet• Praxair Liquid Nitrogen Safety Data Sheet