Good point. Definitely don't put your head in garbage bags or fill the room or not breath enough. Also it's much safer to use a regulator on the tank instead of just rocketing it out at full pressure through a hose. Balloons are relatively safe and self regulating, since you let go of them when you pass out and they zoom hilariously around the room giving everyone another thing to laugh uproariously about, but totally bumming out the dismayed fool who just lost their whole balloon, which at the moment was their most important possession.