Synonym(s): Osmic acid, Osmium tetroxide Formula: OsO4 Formula weight: 254.10 Purity: 99.8% (metals basis), Os 74.4% min CAS Number: 20816-12-0 UN Number: UN2471 Hazard Class: 6.1 Packing Group: I Harmonized Tariff Code:  2843.90 Hazard Statements: H300-H310-H330-H314 …