Alpha Metals 2 oz. Non-Electrical Acid Paste, Flux & Applicator Brush is used for potable water applications. It is NSF 14/61 certified and has a flash point of 540 degree F. The paste is amber in color and has a viscosity of 20,000 to 40,000 cPs. It is compatible with brass, copper, and galvanized iron. The kit includes a brush for easy application. Oatey #5 lead-free paste flux cleans and fluxes most commonly soldered metals including copper, brass, zinc, galvanized iron, lead and tin or copper-coated metals. Fluxing is a critical step in the soldering process. #5 paste flux provides great wetting properties for better solder flow and can be used with most soft solders. #5 paste flux complies with CA and VT lead content regulations.