... ISO9001 CertificateOur Zinc Oxide Grades: Indirect process Zinc Oxide, Direct Process Zinc Oxide,Calcined Zinc Oxide, Zinc Oxide, Pharmaceutic Zinc Oxide, ... meet standard of GB/T3494-1996 Item/Parameter Standard Zinc Oxide (in accordance with dry materials) % ≥ ... % ≤0.006--------Manganese (Mn) % ≤0.0002--------Metallic Zinc (in accordance with Zn) %NoneNone------Muriatic Acid Insoluble Substance % ...