Nitrogen asphyxiation is a medical condition in which a person dies from a lack of oxygen because there is too much nitrogen in his system. This is almost exclusively an accidental death, and it can happen easily because there are no immediately noticeable effects. Since the mid 1990s, nitrogen asphyxiation has been brought up for consideration as a capital punishment but, as of 2011, it has not been used for this purpose. When such asphyxiation begins, it only takes several breaths until it affects the body’s oxygen supply, and a minute of nitrogen exposure may cause someone to fall unconscious. It generally takes less than 10 minutes for someone to die from this, though there may be convulsions beforehand.
Dying by nitrogen asphyxiation is nearly always accidental, and it can happen easily to people who work around nitrogen. Nitrogen is most often found in manufacturing plants, and this is where most of the deaths occur, but some laboratories that are holding nitrogen also may experience this. When someone dies from carbon monoxide or carbon dioxide asphyxiation, they typically will become dizzy and feel pain before dying. Until nitrogen exposure reaches a dangerous level, most people will not feel anything, so there is no warning until the person passes out and eventually dies from the exposure.
In the mid 1990s, nitrogen asphyxiation was brought up as a potential new method for capital punishment. Nitrogen is relatively cheap and there is no noticeable pain from nitrogen exposure, so it has been thought of as potentially more effective than other capital punishment methods. No countries or regions use this for capital punishment as of 2011, however; it has not even been tested for this purpose.
When someone is exposed to a sizable amount of nitrogen, it does not take long for the nitrogen to lower the amount of oxygen in the body. Within several breaths — five or less — there is enough nitrogen to lower oxygen levels. After about a minute, nitrogen asphyxiation begins and the person typically passes out. While this exposure is normally from nitrogen as a gas, liquid nitrogen also can asphyxiate people.
Some people may begin to convulse after passing out, but this is not always the case. The person also may just look like he is sleeping. Most people can only be exposed to nitrogen for five to 10 minutes before it causes nitrogen asphyxiation and death.