Alabama sets January date for world’s first execution by nitrogen hypoxia

The US state of Alabama has said that it will execute convicted murderer Kenneth Eugene Smith on 25 January next year using a method that has not yet been used to deliberately kill a human being, nitrogen hypoxia.

The air that we breathe is normally composed of about 78% nitrogen, 21% oxygen, and a few trace elements. The execution method known as nitrogen hypoxia involves giving the prisoner gas that is pure nitrogen. Advocates argue that this will avoid the sensation of suffocation. The prisoner will feel that they are breathing normally, they claim, but will swiftly pass out through a lack of oxygen, with death following within minutes.

This method was inspired by industrial accidental deaths. Orchards use nitrogen filled rooms to store apples, and nitrogen is also used to purge tanks of other gases. Unprotected people who inadvertently enter these nitrogen filled environments often seem to lose consciousness and die without attempting to escape, indicating that they felt nothing amiss.

Three states—Alabama, Mississippi, and Oklahoma—have …