We Provide high quality Zinc Sulphate Heptahydrate directly from our own factories. Our specs are; TESTS (LIMITS) Zinc (Zn) 22 % min Lead (Pb) 1 ppm max Cadmium (Cd) 1 ppm max Arcenic (As) 1 ppm max Mercury (Hg) 1 ppm max Free Moisture 0,5 % max pH ( in 5% Solution) 3-4 Size Large Grain Free Flow Crystals