... heavy metal lower than 10ppm white prilled, powder Zinc Sulphate Monohydrate, PowderFormula: ZnSO4·H2OCAS No.: 7446-19-7Spec.:DescriptionFeed GradeTech GradeZn35 ... )15ppm max20ppm maxArsenic (As)5ppm max5ppm maxCd10ppm max10ppm maxZinc Sulphate Monohydrate, GranularFormula: ZnSO4·H2OCAS No.: 7446-19-7 Spec.:DescriptionFeed ... in trace element fertilizer and feed additive. zinc sulphate monohydrate