The Columbia Encyclopedia, Sixth Edition. 2001-07.
red lead
bright red to orange-red powder, also called minium, that is used in the manufacture of storage batteries, lead glass, and red pigments; a paint made with red lead is commonly used to protect iron and steel from rusting. Chemically, red lead is lead tetroxide, Pb3O4, a water-insoluble compound that is prepared by the oxidation of metallic lead or of litharge (lead monoxide); the commercial product sometimes contains litharge as an impurity.