"Some Guy" wrote

I said several times that you are proceeding from a point of view that
the handling and processing of returned welding tanks IS different from
that of medical tanks.

I said I don't know if there is a difference. You seem to have a difficult
time comprehending that. Once you do, you will realize there is no reason to
discus this any further. Feel free to assume I mean things I've never said
though, as long as you have fun.



Let me ask you this:

If, hypothetically speaking, a compressed-gas supplier handled and
processed ALL returned O2 cylinders the same way (both welding and
medical cylinders) - which is to say that they are always cleaned,
evaculated, etc, according to medical-grade specifications, then what
would be your argument that an end-user shouldn't purchase a tank of
"welding grade" O2 for their own medical or veterinary purposes from
that supplier?

If it does not have that piece of paper, it is not medical oxygen.

I already replied to that. See the line above.
I'm working with facts, you are working with speculation and hypothetical
speaking.




If I buy welding O2 specifically for medical purposes, I agree that I am
taking some sort of risk that I have no recourse or remedy for should
the tank contain some harmful impurity. But I'm not convinced that a
medical tank has a lower probability of containing a harmful impurity
compared to a welding tank.

You are welcome to your opinion. It may or may not be correct. Find out for
sure and be at ease with your speculation.