Pb3O4

Pb₃O₄ (lead tetroxide) is a mixed-valence lead oxide ceramic compound consisting of lead in both +2 and +3 oxidation states, traditionally classified as a red or orange-red powder pigment and corrosion inhibitor. Historically used as a rust-preventive primer in protective coatings for steel infrastructure, marine equipment, and heavy industrial structures, it has largely been displaced in many markets due to lead toxicity regulations; however, it remains relevant in specialized applications including glass manufacturing, radiation shielding ceramics, and certain electronic applications where its semiconductor behavior and high density provide functional value. Engineers considering this material should verify regulatory compliance for their region, as lead-based compounds face strict restrictions in consumer products and construction in many jurisdictions.