Nitrogen gas can cause suffocation without warning. Store and use liquid nitrogen only in a well-ventilated place.
As the liquid evaporates, the resulting gas tends to displace the normal air from the area. In closed areas, excessive amounts of nitrogen gas reduce the concentration of oxygen and can result in asphyxiation. Because nitrogen gas is colourless, odourless and tasteless, it cannot be detected by the human senses and will be breathed as if it were air. Breathing an atmosphere that contains less than 18 percent oxygen can cause dizziness and quickly result in unconsciousness and death.
Note:
The cloudy vapour that appears when liquid nitrogen is exposed to the air is condensed moisture, not the gas itself. The gas actually causing the condensation and freezing is completely invisible.
Never dispose of liquid nitrogen in confined areas or places where others may enter.
Disposal of liquid nitrogen should be done outdoors in a safe place. Pour the liquid slowly on gravel or bare earth where it can evaporate without causing damage. Do not pour the liquid on the pavement.
First Aid Notice:
If a person seems to become dizzy or loses consciousness while working with liquid