Well I have come on here to have some where to send patients I deal with to go, welding O2 this is crazy to read I shudder to think what oils and other contaminants are going in to your body, there are strict rules and testing in place for medical oxygen for a reason, is it that bad in the states to get O2 bottles as I'm in the UK the NHS supply it on prescription (it's also a controlled drug over in the UK)