When I was a teenager in Texas my sister had a friend that used to inhale freon (A/C refrigerant or something like that). He was taking a bath while doing it one day. He did too much apparently and passed out while in the tub. His mother kept hearing a clanging which turned out to be the bottle spinning around smacking the wall. The only thing that save him from drowning in the tub was his mother going upstairs to investigate the noise and the fact he was taller so his legs didn’t fold far/high enough for his head to go under water.