Is oxygen toxic/poisonous?

Question

I read somewhere that oxygen is, in fact, poisonous, and it “oxidises” your cells, burning you slowly, which is why anti-oxidants are important.

Is there any truth to this?

Thanks!

p.s. not a debate or anything, just want info on the negative/positive effects of oxygen on organic matter and properties of oxygen

p.p.s will this go in chemistry or biology???

In: Chemistry

Answer 1

First of all, oxygen as we depend on it occurs not in single molecules (O) but in the diatomic molecule O2.

And it can in fact have toxic effects depending upon pressure and concentration. In normal air, there is 21% 02, so in pure oxygen at atmospheric pressure there is 5X more oxygen than human body is adapted to. This can cause body problems, so to avoid them and to save weight, NASA used a one-fifth cabin pressure of pure 02 in the Apollo block 2 capsule, and 21%-O2 Earth air at normal pressure in the Shuttle.