Of the air we breathe, nitrogen makes up approximately 78 percent and oxygen makes up about 20 percent. Nitrogen gas is not poisonous itself and whatever people inhale, will be expelled on exhalation.
However, if a person inhales the gas with no oxygen, they will quickly lose consciousness, can suffocate and die soon after.
This is becausewhen people breathe in nitrogen without expelling it, the gas replaces oxygen in the body and those levels plummet. If oxygen levels fall below 10 percent, it can be fatal.
Accidental deaths and suicides from nitrogen exhalation have occurred and because the gas is completely odorless and colorless, people may not realize they are breathing it in at unsafe levels.
Exhaust gases from cars and trucks are major sources of nitrogen.
Using nitrogen for capital punishment is called nitrogen hypoxia and involves putting a mask over someone's nose and mouth and pumping the gas through it.
In another method, the inmate would be sealed in an airtight chamber pumped full of nitrogen.
Proponents of execution by nitrogen hypoxia argue that because a person breathing in copious amounts of the gas will quickly pass out and die soon after, they will not experience any pain in the process.
But opponents of the method argue its use for capital punishment is inhumane and shouldn't be allowed, claiming there is not enough evidence toprove the safety and legality of the process.
They also argue not enough is known when it comes to using nitrogen in this setting and a multitude of things can go wrong, causing harm and pain to the person being executed.
