These were in air tight pods with suction devices to remove the gas. Frequently the gas froze making it unable to kill the prisoner and the room had to be externally heated until it started evaporating. After the inmate strapped in the chair in a tiny pod was dead the suction device would start sucking the gas out but even then it was unsafe to remove the body for hours afterwards and the removal crew would enter wearing hazmat suits.

California’s infamous green execution chamber which was used for lethal injections after abandoning the gas chamber was in fact a requisitioned gas chamber and was too small to really perform the lethal injection in causing many problems resulting in it being scrapped.

But we’re supposed to believe that what we’re essentially sheds outside in polish winter with no suction devices to expel the gas we’re used to conduct multiple gassings of hundreds of people an hour lol.