Oklahoma is at it again. After the botched execution of Clayton Lockett and the Supreme Court recently has taken up the constitutionality of the current lethal injection protocol that Oklahoma uses they have found a new option. The execution of Lockett failed and he ended up dieing of a heart attack 43 minutes later. Today Oklahoma passed into law death by inert gas asphyxiation as a secondary execution method which would only be used in the case of the Supreme Court striking down lethal injection or if they are unable to find the lethal injection drugs(midazolam, vecuronium bromide, and potassium chloride) Oklahoma will now use Nitrogen. They will place an execution hood on the condemned prisoner and fill it with Nitrogen until he passes out and eventually dies a few minutes later.
In theory this should be a relatively painless way to go but this is unproven grounds. According to Wikipedia 109 people have committed suicide using this method but they failed to give any type of source or how they calculated that amount. I could not find any statistics on it either.