Salt spray testing uses a closed chamber to subject samples to a saline (or salt) spray. This test is generally performed to evaluate the integrity of a coating in a corrosive environment, or to test the corrosion resistance of a product or material.

Salt spray testing may also be referred to as neutral salt spray (NSS), because the pH level of the saline is between basic and acidic. Depending on the standard or test plan chosen, samples are exposed to the spray solution for a predetermined period of time, and checked regularly throughout testing to evaluate their performance.

Typical results from this method include rusting, blistering, peeling, etc. The most commonly used standard for salt spray and neutral salt spray is Testing Methods: ASTM B117 & ISO 9227.