That can be done with any gas. Just exclude oxygen and any gas will work.
Carbon monoxide comes to mind.
But nitrogen is dirt cheap. Air is about 78% nitrogen already; separating out the 21% oxygen is a fairly simple and inexpensive process.
They purport to use nitrogen; as with it and helium, both are inert gases and will not cause the “strangulation” effect that cyanide or CO2 would cause in the body.
Replace the oxygen with helium with his face uncovered. Leave him alone in the chamber screaming for mercy in a high pitched voice. Make it a pay per view. Fun for the whole family!!
Replace the oxygen with helium with his face uncovered. Leave him alone in the chamber screaming for mercy in a high pitched voice. Make it a pay per view. Fun for the whole family!!
Biologically yes. BUT the body does sense concentrations of other gasses and will react. The body senses increases in Co2 and will create a stress reaction. Probably not a good choice for execution (opinions of FR aside).
The body does not sense the absence of O2 and will not react to the resulting suffocation. Inspectors of cargo ships have died almost instantly inspecting the hold of the ship carrying scrap steel. The rusting steel removed all the oxygen. Inspectors never knew what hit them.
Not quite.
They could use helium or nitrogen because they're largely inert and non-toxic. All they do is displace the gas in your lungs and don't otherwise interact with any tissues. They displace the oxygen, which will cause you to lose consciousness and die, but they also displace the carbon dioxide, which is what triggers the urge to breathe and makes the whole experience unpleasant.
Without the CO2 build-up it isn't unpleasant. If you've ever took a lung full of helium from a kid's balloon and held it in too long, you know the truth of that.
But chlorine, bromine, fluorine and iodine also all are gasses, and also are toxic. With any of them you'd start having an unpleasant reaction immediately when the goal is that you drift off to sleep without any discomfort.
And if you're going to do that, why bother giving up cyanide gas?