Osmium Tetroxide

**Semantic type:** Inorganic Chemical

**Definition:** An osmium oxide composed of four oxygen atoms bound to a central osmium atom. Osmium tetroxide is most commonly used as a fixative, and in oxidation reactions and biological staining. It is characterized as a colorless, or pale-yellow crystalline solid with a pungent odor. Exposure occurs by inhalation, ingestion, or contact.

**Synonyms:** - OSMIUM TETROXIDE - Osmium(VIII) Oxide - Tetraoxoosmium