Chemical Specifications Appearance White crystalline powder Assay Min. 99.0% Chloride (Cl) Max. 0.0025% Sulphate (SO4) Max. 0.02% Total nitrogen (N) Max. 0.005% Heavy metal (as Pb) Max. 0.002% Iron (Fe) Max. 0.001% Residue on ignition (at 800°C) Max. 0.05%