1.Zinc Sulphate Hepta Powder. Specifications: Zn: 22.5%min. Fe: 60ppm max. Pb: 10ppm max. Cd: 7ppm max. As: 5ppm max. Water insoluble matter: 0.05%max. Packing:25kg pp bags. 2.Zinc Sulphate Hepta Powder 21%min.