2airishuman
Contributor
From what I understand, the packaged gas industry in the United States is for the most part purchasing UN certified cylinders rather than DOT certified ones at this point. I don't know whether they are CE certified or not. I don't know if it's required. You can use a UN cylinder in the United States, that is marked to UN standards, hydro'd to the UN intervals, and filled to the UN pressures, and it does not need to meet the DOT specifications.
