This standard specifies procedures for testing coating water resistance under 100% relative humidity conditions to assess the performance of coatings in extremely wet environments. This method is used to determine the performance of coatings under fully condensed conditions and helps to understand the resistance of coatings to moisture in practical applications. The standard covers the assessment of coating failure, including defects of the coating itself and its impact on substrate treatment. Test results can be used for coating specification acceptance, quality control and research and development, but should not be equivalent to moisture exposure in the natural environment. This method is suitable for a variety of testing equipment, including small laboratory cabinets and large test rooms.