Rules for the handling of liquid nitrogen

Liquid nitrogen handling entails risks of accidents and ill health. Management for liquid nitrogen management is AFS 1997: 7 "Gases" and AFS 2000: 4 "Chemical Hazards in the Work Environment".


Handling refers to the storage, transportation, use, disposal, manufacture, processing, treatment of, packaging, destruction, conversion and similar procedures. (AFS 2000: 4)

General rule

Work with liquid nitrogen may only be carried out by the person who has sufficient knowledge of the risks that may arise during handling and use, as well as how these can be avoided. The immediate boss will ensure that the employees dealing with liquid nitrogen have knowledge of the risks and have been informed about the local instructions for handling and protection that have been developed.

Common risks when handling liquid nitrogen

Liquid nitrogen is a colorless, odorless and tasteless liquid. The gas is not toxic and does not burn. The boiling point is -196º C at atmospheric pressure.

When handling liquid nitrogen, the low temperature means the risk of cold damage.

Unprotected moist skin can temporarily freeze on metal objects cooled down by liquid nitrogen, which can cause severe wounds to occur during the release.

Also note that many types of materials (such as plastics) do not withstand the low temperature of the fluid, which can cause major risks to the user.

At +20 degrees nitrogen gas takes 694 times as much space as the liquid. This means that when the gas is transferred into liquid nitrogen there is a risk of displacement of air oxygen, which may cause oxygen deficiency. This is especially evident in closed spaces such as lifts (see below for internal transportation) or cars, but also in areas where liquid nitrogen is stored or used. No tightly sealed lids may be used unless they are equipped with pressure valves. For the same reason, larger containers (such as transport containers) without a safety valve may under no circumstances be completely sealed. If a container can’t be opened and the gas is not able to get out of the container, help via SOS should immediately be called (call 112).

Example: In an elevator that is 2x2x2 m, (8 m3), it is sufficient to waste 0.35 L of liquid nitrogen so that the oxygen content becomes dangerous, ie <18%.

Protective gear

Always carry visors when transporting, refilling and handling liquid nitrogen, special gloves, full-length shoes (not for example rubber boots with fitted pants) and protective clothing.

First aid

High levels of nitrogen can cause choking, which may occur without warning. Symptoms may also include unconsciousness. In case of respiratory distress, the injured person should immediately be moved safely from the source of nitrogen. The injured person should be kept warm and quiet. Call a doctor. Give breathing assistance if breathing ceases.

In case of splashes in the eyes, rinse immediately with plenty of water for at least 15 minutes. Doctors should always be contacted.

Frozen body part is thawed with mildly warm water until the skin regains feel and normal color. Do not rub or process damaged body parts. Such treatment can worsen the damage. In case of deeper or more extensive cold damage, a doctor should always be consulted. The throat must not be interrupted during transport to hospital.

Internal transportation

Small amounts of liquid nitrogen (1-10 liters) are carried out by employees carrying the vessel directly to the area where the vessel is to stand. Transportation of larger quantities (> 10 liters) takes place by cart or special carriage. The transport must be carried out in such a way that the vessel can’t be overturned. In case of elevator carriage, no people may be included in the lift, and the button labeled dangerous goods must be activated.


If a small amount has been spilled, leave the premises and judge if further action is required. What action will be taken depends on space, activity and air change. In case of large discharge, the area should be closed. Purification is done by venting. If possible, avoid spillage to the drain. Liquid nitrogen must not be poured into the sink. Small vessels are placed in a drawer cabinet where the nitrogen can be dumped without risk.

Transportation in vehicles

The most serious danger of transport in vehicles is in case the vessel overthrows, and there is risk of choking, but this risk already exists without vessel overthrow. Driving in passenger cars is not only inappropriate but also illegal. When transporting liquid nitrogen, regardless of amount, the driver must have approved ADR.