Red Dan, also known as Lead Dan, Bright Dan, alias Zhang Dan, the scientific name of lead oxide; for the bright orange-red powder, specific gravity 9.1, at 500 ℃ when the decomposition of lead monoxide, insoluble in water and alcohol, soluble in nitric acid, partially soluble in glacial acetic acid, soluble in hot alkali solution. It is easy to change into black lead sulfide with hydrogen sulfide, and it is poisonous to generate lead sulfate into white color when exposed to air. Mainly used in the manufacture of antirust paint and optical glass, ceramic glaze, enamel and pressure-sensitive components of the electronics industry, the chemical industry is also used as a weak oxidizing agent.