> it's very flammable

Nit: oxygen is not flammable. Other things are flammable in its presence. A lump of coal, for example, burns white hot when oxygen is blown on it from a welding torch.

Touche.

Still, it's a fire hazard.

But if you have a personal mask, aren't this then mostly your own microorganism, your body knows how to deal with?

The fire hazard is a real threat, yes, but I imagine, if I ever would have serious trouble breathing, the first thing I would get is a bottle of oxygen to ease it.

I'm a little uncomfortable with the line of questioning here because it is starting to veer into sounding like asking me for medical advice.

I've left comments previously about airway clearance techniques and home remedies I've used. They probably aren't hard to find if you care to read them.

I have an incurable condition and impaired immune system. I personally don't like dealing with anything like masks. I've done it in the past. I know how hard it is to keep them adequately sterile.

I am not a doctor. I am not here to give medical advice in comments.

I know that, I did not really ask for advice, more for your experience. And since you do not have experience with oxygen, I was merely suggesting it, as I heard how it helps people with breathing problems and I do not see the need to have the masks 100% sterile if it is your personal mask. But I am also not a doctor ..

My personal experience is that you do need to diligently sterilize things like masks that only you use. I spent years boiling medical equipment daily.

I had a nebulizer for a time to administer inhaled treatments. It had to be carefully sterilized.

Failure to adequately sterilize your personal medical equipment is sometimes a source of very nasty antibiotic resistant infections.

Your own germs or not, once they leave your body and grow on a surface and come back in contact with you, you had better take it seriously as a threat to your health.

Thank you, for sharing.