This International Standard specifies two accelerated corrosion-test procedures, Methods A and B, for the comparative evaluation of metallic materials with or without permanent corrosion protection or temporary corrosion protection in outdoor salt/acid rain environments. It also specifies the apparatus used. The two tests involve cyclic exposure of the specimens to acidified salt spray, “dry” and “wet” conditions. The particular advantages of the two tests over conventional accelerated tests, such as the neutral salt spray test (NSS) as specified in ISO 9227 lie in their better ability to reproduce the corrosion that occurs in outdoor salt/acid rain environments. They are also useful for evaluating cosmetic corrosion. Method A applies to — metals and their alloys, — metallic coatings (cathodic), — anodic oxide coatings, and — organic coatings on metallic materials. Method B applies to — steel coated with anodic coatings, and — steel coated with anodic coatings covered with conversion coatings.