Aviation Oxygen

[divbum]

For the couple of dollars it may differ depending on your price level, I find it foolish to not use a spec gas.  Aviation is a Breathable gas - garenteed - industrial is not.  From that point everyone will go into it comes out of the same truck - but the cylinders being filled do not get handled the same way - vacummed and refilled at all shops.  The closer to liquid the fill the better the quality.  Industrial gets filled last.
I guess it depends on what your life is worth- how much at your price will this save per bottle and per year?  I smoke a pile of 02 annually.
Next a reduced partial pressure of an impurity will not likely kill the piloit- but the increse PP of unknown at depths may kill us.  I am simply not taking that chance.