I use pure oxygen. I have a tank in my shop and a tank on my truck. All the bait stores that I service have pure oxygen tanks. We have a medical supply company in town here. They have a route that they actually come and replace the leased tank, when it is expired. You could find a medical company in your area and ask for the real small tanks. Welding shops also use pure oxygen. That would be another place to check. I would never ship, unless it had pure oxygen in the bag, or one of those Kordon bags. In fact, I am not yet sold on those bags for high volumes. (head count). But, I have not done the research into those bags either.