Red lead is lead tetraoxide, also known as lead Dan. Bright red powder at room temperature. After blending with oil, apply to iron to prevent rust. Sometimes used to prevent miliary, but because it contains lead, easy to cause lead poisoning, it should be used with caution.

Red lead, also known as lead Dan, lead red, molecular formula Pb304. Fresh orange red heavy powder. Specific gravity 9.1, at 500℃ decomposition into lead monoxide and oxygen, insoluble in water, soluble in hot alkali solution. There is oxidation. Dissolves in hydrochloric acid to produce chlorine gas. Dissolved in sulfuric acid to produce oxygen. Used in the production of batteries, glass, pottery, enamel, and used as anti-rust pigments and iron protective coating, and other organic synthesis of oxidizing agents. Produced by intensely heating lead monoxide in an air stream. Fuels and others are highly resistant to corrosion, high temperatures, but not acid. Red lead is used as an anti-rust agent, and the paint made with it has strong adhesion and considerable stability in the atmosphere. Therefore, steel Bridges, ships, machine pipelines are painted with red lead primer. Also used in batteries, glass, mirror, etc.