Product Name ; Zinc Sulphate Heptahydrate (EP/LR) Chemical Name ; Zinc Salt Heptahydrate CAS No. : 7446-20-0 Color & Physical Form ; White Crystalline Powder Active Ingredient : ZnSO4.7H2O Assay L 99 - 102% Molecular Wt. ; 287.54 pH : 4.0 - 6.0 Zn-Content ; Min. 21% Chloride : NMT 0.01% Iron : NMT 0.005% Copper ; NMT 0.0005% Cadmium ; NMT 0.001% Total Nitrogen : NMT 0.005% Heavy Metals (as Pb) ' NMT 0.005% Loss on Drying (105 degree C) : 35% - 39%