I'm pretty sure I read that if you put enough gaseous oxygen into someone's veins they'll die. And every day for as long as I can remember I've needed the stuff Although I've never been able to hold on to it for very long. And I know in the end of Jaws a big tank of it exploded.
What I'm trying to say is that maybe you and I are one of those tanks. The ones they keep in hospitals and submarines and other lonely places.