Also, and keep in mind I have never killed myself using this method, so I don’t know first hand, but, nitrogen is lighter than carbon dioxide, so if the person had 100% pure nitrogen to breathe, and no carbon dioxide, and is maintained with their head near the top of the pod, they would have died fast and allegedly without feeling it.

However, I am absolutely convinced that the people responsible for this execution did research on how to make this method as painful as possible (done right, it is apparently euphoric, and there is NO WAY they would even remotely take the risk of this happening), so they probably went out of their way to have a nitrogen-oxygen mix (like our atmosphere), but with lower amounts of oxygen, and forced the person to stay in a position that would guarantee they would die from CO2 asphyxiation rather than nitrogen.

It is even more inhumane than just using CO2 (as is done in meat “production”), because it prolongs the suffering quite a lot… The whole point of using CO2 on animals is to expedite the process… at the expense of their suffering.