Galvanization prevents rusting of steel and iron through application of a protective zinc coating. Galvanization can be done with electrochemical processes. In industry, galvanized steel is used in air ducts and trash cans. There are two common methods of galvanization, hot-dip galvanization or electro-galvanization. Galvanized piping is used for interior drinking water service, but is being replaced by copper and plastic piping. Galvanized steel pipes are still used in outdoor applications where mechanical strength is required.