... Tons/ YearAppearance white or colorless crystalMesh Available 10, 8-16, 30, 40, 60, 80, 100-120meshPurity 99%, 80%, 70% or customizedFlavor ... .0% maxAmmonium (NH4) 0.02% maxSulfate (SO4) 0.028% maxIron (Fe) 30 ppm maxHeavy Metals (Pb) 10 ppm maxArsenic (Aso3) 1 ppm ...