CAS: 7727-21-1 EC No: 231-781-8 MDL No: MFCD00011386 RTECS: SE0400000 UN No: UN1492; Haz Class: 5.1; Packing Group: III Crystalline/Powder Linear Formula: K₂S₂O₈ MW: 270.31 Melting Point: 100° Density (g/mL): 2.477