On Sun, 20 Jun 2010 12:28:09 -0500, Pete C. wrote:

Ed Pawlowski wrote:

"Some Guy" wrote
Like I just said, the presence of impurities does not necessarily equate
to medical safety or have a health impact. If those impurities are
nitrogen or water vapor, then what exactly are the health implications
of those?

But if the analysis does not say what the impurities are, you are trading on
dangerous ground. That welding tank may have been used along with any
other gas used in industrial environments.


You can't use welding O2 for medical purposes

Says who?

A lawyer? Or a biochemist?

Lawyers and other sensible people that do not know what other gas may be in
there. Oxygen falls into the same type of situation ad drugs. The active
ingredients of a pill are often a small percentage of the tablet, the rest
being inert ingredients. There are regulations on what those inert
ingredients can be. There are regulations on how they are handled.

If I was dying in an emergency situation from lack of oxygen, I'd grab any
tank available. If I was at home with COPD, I'd want to be sure that tank
was handled in a proper manner and would not make me worse off.



You're stuck on old paranoia based on information that is decades out of
date. All of the O2 purity grades specify no more than 0.05% impurities,
and the most lax of the standards is the medical / aviator grade. The
reality is that all the grades are filled from the same cryo O2 source
and all are better than 99.99% pure O2.

Again, you ignore impurities and only look at the O2 percentage.