sulfamic acid / sulphamic acid sulfamic acid is apowder/ crystal form used as safe descaling cleaner, it can be used in all types of metals to clean and remove scale and rust . its highly recommended to use sulfamic acid instead of muriatic acid which is higlhy corrisve and non safe and same time cant be used in all metals, while sulfamic acid is safe to use, no fumes and can be used in all types of metals including stainless steel, carbon steel. you can use sulfamic acid to clean your cooler, heat exchanger, boiler, cooling tower ...exc