STPP Tech Grade 94%min Appearance: White Powder Na5P3O10: 94.0%Min P2 O 5: 57.0%Min Water Insoluble Matter: 0.10%Max Iron(Fe): 0.007%Max PH value (1% water solution): 9.2-10.0 Whiteness :88%Min Ignition: loss 1.0 Density (g/cm3): 0.65-0.99 Phase I: 10-30 96% Packing: 25kg/PP bag