taking 75 minutes, will release approximately 85 m
3
of
nitrogen gas.
POxygen-deficiency alarms must be installed. Guidance on
ventilation requirements are given in BCGA Code of Practice
CP30, The safe use of liquid nitrogen dewars up to 50 litres.
PThe exhaust port/ports must be connected to ducting that will
route the exhaust gas away from any spaces where nitrogen
build up can occur. Under no circumstances should the
exhaust duct be connected so that the exhaust is released into
a confined space.
PWhen there is a risk of reduced or insufficient ventilation
when a room is unoccupied, then alarms to indicate oxygen
deficiency must be installed and positioned outside of the
room so that operators are aware of the hazard before
entering. The operational status of such an alarm should also
be visible from outside the room.
PIf liquid nitrogen is used in an area that requires forced
ventilation, an alarm to indicate its failure should be fitted.
PWhen dispensing or potentially being exposed to liquid
nitrogen, protect the face with a shield and wear gloves, boots
and a protective apron. Prevent spillage into shoes and onto
unprotected parts of the body.
PHandle vessels containing liquid nitrogen carefully. Liquid
nitrogen boils at -196ºC and both liquid and gas can cause
rapid and severe frostbite. Delicate tissue, e.g. the eyes, can
be damaged by an exposure to the cold gas, which may be too
brief to affect the skin of the hands or face.
PStand clear of boiling and splashing liquid nitrogen and its
gas when filling a dewar at normal room temperature or when
inserting objects (such as a pump) into the liquid.
PUse tongs or wear cryogloves when handling cold or hot
objects. Cryogloves are available as an accessory from Planer
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