Containers for such liquids must therefore be selected carefully to ensure that they can withstand the temperatures and pressures they may be exposed to. Liquid nitrogen is commonly stored in Dewar flasks which should be taped to minimize the hazard in the event of an implosion. A common use of liquid nitrogen is as a coolant for traps incorporated in vacuum lines. Extreme care must be employed when using liquid nitrogen as a cold trap coolant. Systems including liquid nitrogen traps must never be opened to the atmosphere until the trap is removed from the coolant.
Liquid oxygen forms highly explosive mixtures with many organic materials.
Consequently, liquid argon will condense in a reaction vessel under an argon atmosphere which is cooled with liquid nitrogen. Consequently, never cool an apparatus that is under an argon atmosphere using liquid nitrogen. Return to index of Chemical Research Safety Notes.