- Antimony trioxide is the inorganic compound with the formula Sb2O3 it is the most important commercial compound of antimony.
- It is found in nature as the minerals valentinite and senarmontite.
- Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions only with hydrolysis
- When used as a flame retardant, antimony trioxide is often used in combination with halogenated compounds. Antimony trioxide is used as a synergist to enhance the activity of the halogenated flame retardant