ISO 8502-2-2017 standard is one of the international standards for assessing the surface cleanliness of steel substrates before painting, focusing on the determination of the amount of chlorides on the surface. This standard describes a method for determining the presence of water-soluble chlorides on steel surfaces, suitable for both field and laboratory environments. Cleaning of steel surfaces before painting, especially for rusting and Miscellaneous contaminants that may be present, such as grease and dust, is essential. Implementation of this standard helps to ensure that coatings adhere effectively without surface contamination, thus improving the performance and durability of protective coatings.