[newacct583]

I eagerly await the coming flood of DIY oxygen chamber tutorials. Hopefully no one gets hurt.

FWIW: high concentration O2 is known to be toxic in other ways. It causes lung inflamation at least (oxygen is, after all, highly reactive and tends to break up lots of different molecules). I think there's a real possibility that this does more harm than good.

[ThrowawayR2]

I think fire would be the most direct concern. IIRC, a lot of things become flammable in a high or pure O2 atmosphere that aren't normally considered flammable.

[Sunspark]

Ozone (O3) is definitely the one that is very reactive and bad for your lungs.

[newacct583]

Ozone is indeed acutely toxic. But no, plain O2 will attack pretty much anything (i.e. literally everything in your body can be "burned") with a reaction rate that depends on concentration. At a partial pressure of 0.2 bar, that's negligible, but it stops being so at some point.

It's a known thing in diving planning, here's a wikipedia article on it: https://en.wikipedia.org/wiki/Oxygen_toxicity

Now, I'm sure these chambers aren't at those pressures. But everything is likely linear, and the thing they're "curing" is literally what we currently consider to be the normal baseline! Even a very small effect will swamp whatever longevity benefits they're seeing are.