This standard practice covers testing criteria for evaluation of protective coating systems for use on iron and steel surfaces. It is not recommended for the evaluation of hot-dip galvanizing or metalizing. The protective coating systems are intended for use on bridges, similar structural steel, and other ferrous metal surfaces, both new and existing, prepared by abrasive blast cleaning, which are subject to corrosive atmospheric environments, such as marine, industrial, deicing chemicals, and high humidity. Note—The testing format for this standard practice has been developed around a three-coat system consisting of a zinc primer, epoxy or urethane intermediate, and an aliphatic urethane finish coat.