Re: Oxygen is not flammable
Before you get going on this, you might want to read up on the Dunning–Kruger effect.
No they don't
Yes we do.
you can't use pure oxygen underwater due to oxygen toxicity.
You can use pure oxygen underwater despite oxygen toxicity. And we do.
Even enriched oxygen products limit the depth you can dive
Indeed they do. But high-O2 mixes - up to 100% for some people - reduce the time required to decompress from dives. And that is why we use them.
The only time you have high purity oxygen in diving is for post-dive medical treatment for decompression sickness (which wouldn't be frequent) or submersible which is mixing its own gas ratios (once again, not common).
Nonsense on both counts. High-O2 mixes are useful as decompression gases, and there is a whole community of us that carry 100% O2 for continuously mixing our breathing gas underwater. Just because you don't know about something doesn't mean it doesn't exist...
Medical oxygen is usually a minimum of 90% and a maximum of 96% pure oxygen.
Diving Oxygen is better than 99.5% pure, and usually better than 99.9% pure.