I know they use Carbon Monoxide in packaged meat.
What’s the advantage of N over CO in executions?
Global warming....
Every breath you take is 78% Nitrogen. It doesn't trigger a choking response in the body. That's why places that use a lot of N2 for industrial processes have all kinds of regulations surrounding it you die without ever knowing you were dying. It is absolutely perfect and is what should have been used all along.
CO2 stimulates the breathing reflex. The subject starts to pant. CO Carbon Monoxide acts rather slowly. Nitrogen does not stimulate the reflex. and it's over in just a few minutes.