Salt spray testing is one type of corrosion test for metallic materials. Depending on the objective, this test method is often adopted for corrosion testing due to several reasons: its test procedures are standardized by ISO and other organizations; it's easy to compare results thanks to a wealth of past data; and salt is one of the major causes of atmospheric corrosion.

While metallic materials with plating, inorganic coatings, or organic coatings immediately come to mind as subjects for salt spray testing, it also targets paints applied to metal surfaces, and even plastics, which are unrelated to metals. These applications are also standardized.