I can't seem to edit my posts so I wanted to add that I know this is an old article and but I'm just posting it because THIS IS THE REASON I got freaked out about using whippets...I found out about the passing out from lack of oxygen thing. Actually, I didn't do any research to find this out, I found out rather spectacularly. A friend of mine did 3 whippets in a row, passed out while standing up and bashed his head open on the corner of those hard wood dorm bedposts (this was in college.) He almost didn't survive. I never did another whippet. So it's rather besides the point for me whether the high is caused by lack of oxygen or from an ingredient in the gas, it is a FACT that you DO deprive yourself of oxygen and that is scary.