Lanthanum metal is used in the foundry industry and is added to cast iron and various alloys. It is also used as a reducing agent. In oxide form, it is used in optical and chemically resistant glass such as camera and telescope lenses. It is also used in the production of pigments, paints and varnishes. It is also indispensable in automotive exhaust and petrochemical catalysts. It is used as an activator in the production of phosphors. It is also used in the production of animal feed and artificial fertilizers.