[RetiredScientist]

Nitrogen gas will replace the oxygen in the feed and the convicted felon will pass out. There are many other ways that would work but this one is foolproof. I used to work with liquid nitrogen and we needed to make sure we had good ventilation.

[rlmorel]

Right. See my post above. You know this all too well.

A pure nitrogen atmosphere is extremely hazardous because you simply have no ability to do anything once you take a breath.