Aviation Oxygen

[Vtach]

Its good to see some activity in the advanced discussion forum.

I agree with you that all oxygen probably comes from same bulk area.  I think the bigger issues for me are how the tanks are treated and guaranteed purity.  I have been told by my supplier that industrial tanks are not routinely vacuumed and are not guaranteed for the same purity as breathing gases.
I think in general you are getting a relatively equal purity between grades of oxygen but contamination is more likely to happen to unvacuumed cylinders and the gas companies liability is much higher with breathing gases, hence the guaranteed purity standards.  I guess I don't see a prohibitive financial issue with using ABO versus medical and industrial.  So I go with what will work best for me and gives me peace of mind in knowing I have a generally accepted standard of purity in each breath.

FWIW, I have 3 T's of oxygen and 3 T's of helium.

$16 oxygen.....
$60 helium......
$300 yearly tank lease.....
$400 digital fill whip......
my own personal trimix/deco gas filling station.......PRICELESS