Pharmaceutical companies will not sell to prisons for executions. I always favored nitrogen asphyxia. Somewhat slow, painless, and there are no hazardous substances (80% of the atmosphere) to deal with. One jamoke who was executed using a face mask made gasping sounds and writhing gestures under the restraints, but he was almost certainly feigning distress to embarass the authorities or in hopes of a temporary repreive. He died.
“The restraints are too tight. They hurt!”
“No worries, we’ll loosen them once you are dead.”
Carbon monoxide. Heck, some folks self-administer. Doesn’t hurt. Cost - a tank of gas and a vent pipe.
I know of someone who used helium to take their life.
Hooked up an oxygen mask to the bottle, laid down, went to sleep, and died.
“ Pharmaceutical companies will not sell to prisons for executions.”
Home Depot and Lowe’s sell it under the brand name “Liquid Plumbr”