GB/T 2423.18-2021 "Environmental Testing - Part 2: Test Methods - Test Kb: Salt Mist, Cyclic (Sodium Chloride Solution)" was released in May 2021 and implemented in December 2021, replacing the 2012 edition and adopting the international standard equivalently. This standard addresses the corrosive effects of saline atmospheres on metallic and non-metallic materials, specifying eight cyclic salt mist test methods. It outlines requirements for the preparation of salt solutions, test equipment, cycle periods, and severity levels to simulate complex corrosive environments such as marine and saline-alkali land conditions. Applicable to products that require resistance to salt mist, including electrical and electronic equipment, automotive components, and outdoor devices, the standard focuses on evaluating their corrosion resistance and protective reliability. It provides a unified basis for product development, quality testing, and export certification, ensuring international mutual recognition of test results.