Standard Inspection FCCNo Specification Standard to Value1 Main content 85.0%min2 P2O5 53.0%min 3 Chloride as Cl 0.025%max4 Sulphate as SO4 0.4%max5. Heavy metals as Pb 0.001%max6 Arsenic as As 0.0003%max7 Fluoride as F 0.003%max8 PH of 1% water solution 9.5- 10.09 Water insoluble 0.05%max10 Whiteness 90%min