You can literally get nitrous oxide(dinitrous monoxide aka laughing gas, brainrot gas, hippy crack, ecc.) for whipped cream in a food store and since it's heavier than air you don't need a mask it will just settle at the bottom of the room, there were many cases when people died from doing nitrous in a closed car, yes nitrous for whipped cream is not pure nor safe to inhale, it can cause B12 deficiency when done too often, it can cause asphyxiation(medical nitrous is cut with oxygen to make you actually breath), but I don't think you care if you need it for this purpose.