Whilst the risk of overdose from nitrous oxide is low, people with heart conditions, abnormal blood pressure or lung conditions may be at higher risk as to the drop in oxygen levels caused by inhaling the gas raises the heart rate, which could cause problems.
When inhaling directly from bulbs or cylinders, the gas is intensely cold (-40C degrees) and can cause frostbite to the nose, lips and throat (including vocal cords). As the gas is also under constant pressure, it can cause ruptures in lung tissue when inhaled directly from these containers. Releasing the nitrous oxide into a balloon helps to warm the gas and normalise the pressure before inhaling.
People can also harm themselves if they use faulty gas dispensers on large cylinders, which may explode. Dispensing multiple gas canisters with one cracker (a handheld device used to 'crack' a nitrous oxide bulb/whippet) can also cause cold burns to the hands.5
To reduce the risks associated with misusing nitrous oxide DON'T:
use it alone or in dangerous or isolated places
put plastic bags over your head or restrict breathing
spray near flammable substances, such as naked flames or cigarettes
drink alcohol or take other drugs
stand or dance while inhaling, as you may pass out
use large volume cylinders due to the higher risks of overdose
