we can supply Sodium Acid Pyrophosphate (SAPP) with fast, medium & slow reaction rate Spec: Disodium dihydrogen pyrohosphate % Min. 95.0 Water-insoluble constituents % Max 1 Arsenic (As) mg/kg Max 2 Heavy Metal (as Pb) mg/kgMax 10 Fluoride (as F) mg/kgMax 10 pH (1% aqueous solution)4.0+0.5 Chromium (Cr) mg/kg Max 1 Nickel (Ni)mg/kg Max 1 Cadmium (Cd) mg/kg Max 1 Lead (Pb) mg/kgMax 1 Size: 90%min passing 200mesh