Cryoliquids

General information

• Wear clothing that covers arms and legs completely; wear closed-toe safety shoes.
• While filling or transferring liquid gases, wear insulating external page gloves and safety goggles.
• To prevent excessive evaporation of liquid nitrogen, never empty cryogenic vessels with a volume greater than 40 l completely. This measure also prevents the formation of ice in the cryogenic vessels.
• The evaporation of 1 litre of liquid nitrogen produces 700 litres (0.7m³) of nitrogen gas. Cold, gaseous nitrogen (produced during the transition from the liquid to the gaseous phase) is denser than air and displaces oxygen (so there is risk of asphyxiation!).

Transport

• Make use of the correct transport routes: take only freight/cargo lifts or a stairwell (never use lifts where staff and students may be present).
• After the transport, helium dewars must be connected immediately to the helium recovery line.
• Liquid gases must not be transported in private vehicles.

Warning signs