Steve B wrote:

"Ed Pawlowski" wrote in message
...

"Some Guy" wrote in message
...
Ed Pawlowski wrote:

Certification. Medical oxygen has to be certified to a certain
purity, welding does not.

How exactly can compressed oxygen be "impure" ?

Are some oxygen molecules more pure than other oxygen molecules?


The content of bottled oxygen is not 100% pure. It is 99.xxx% pure. That
other tiny amount can be anything in the atmosphere or it can be some
contaminant from the bottle. I used to work with medical oxygen and
every batch had a certification giving the purity.



Or does the Medical oxygen tank look nicer and cleaner than the Welding
oxygen tank?

You pay for that test and the potential liability that goes
along with it.

I think you pay more for medical and aviation O2 because the
consequences can be more expensive if there is a problem with the
product (the product being compressed oxygen).

That is what I just said above.


The product itself is no
more expensive or different or has any additional processing steps done
to it on the basis of it's sale in it's variously-labelled forms.

It has a step that does not have to be taken with welding oxygen.
Certification. O2 tanks have been contaminated in the past. Rare, but it
has happened. Filling my own tanks, I'd not be concerned about using
welding oxygen, but I'm not so quick to grab a tank off the back of a
truck at a job site and start breathing it. If you get the certification
with welding grade, then it is the same. That piece of paper is worth a
lot of money if there ever was a problem.

When I was a commercial deep sea diver, the oxygen we used in decompression
chambers was the same oxygen that we used for OA cutting. We did not use
medical oxygen.

I've seen this as well, just one big rack of "welding" O2 cylinders,
grab one for cutting, or grab one for the hyperbaric chamber, all the
same.