In Reply to: Oxygen posted by Roger Gledhill on June 17, 2006 at 10:07:05:

As previously stated, many dive shops use "Aviators Breathing Oxygen" known as "ABO".

Though O2 is O2 is O2, how it’s handled is different. Cylinders that are to be used for “human consumption” such as medical and ABO O2 are pulled to a vacuum before filling to assure there won’t be some strange gas contaminating the O2. There is no such guarantee with welding O2.

That said, some gas suppliers find it cheaper and more efficient just to treat all cylinders the same, so even welding cylinders may be vacuumed before filling.

But again, there’s no such guarantee with welding O2.

Roak

Ps. I second the motion for you to get the "Oxygen Hacker's Companion"