We do test UN ISO tanks. We can’t test tanks that don’t have the UN circle logo before the ISO number. A UN ISO is the European standard for air tanks much like our DOT/ PHMSA standards to insure safety. In 2006 a trade agreement with the EU allowed the sale and use of UN ISO bottles in the United States. The European Committee for Standardization (CEN) tests, monitors, and qualifies the standards with the International Organization for Standards (ISO). Any UN qualified ISO bottle has undergone thorough independent testing and will be safe. If the just has an ISO number there is no guarantee that those standards match up to the bottles with DOT/PHMSA approvals and are not allowed for use in the U.S.
In summary, if your tank has the UN encircled symbol in front of the ISO number, you are good. You can buy, sell, fill, and get your tank hydro tested. If you don’t have the encircled UN symbol your tank was never supposed to be sold in the U.S., Canada, or European Union and it can’t be filled or hydro tested in the U.S.
This blog was written by Nick Morrione. References include: 49 CFR 180.207, ISO 11623-2002, Part 5 of the United States Code 552(a) and Part 1 of the Code of Regulations 51 from date of action 71 FR 33894, June 12, 2006.