Are OG-100 certifications mandatory in the U.S.?

OG-100 certification for solar thermal collectors is not mandated at the national level, but it is required by incentive programs, building codes and other regulations in dozens of states. Therefore, in order to install or qualify for vital solar thermal incentives, an OG-100 certification is required in most locations in the U.S.

So, OG-100 certification is not required to import products into the U.S. But it may be required in most locations to install the solar collector.