If you read the label carefully on a new tank, you might find the information you need. One of my students just got a new Catalina AL 40 for use in decompression. The label clearly said the tank was created O2 clean, but they can't atually call it an OW clean tank because they don't put the valve it and you could possibly place a contaminated valve on it. Put an O2 clean valve on a brand new tank that still has its cap on it, and you should be ready to go.