Appearance White powder Assay (as MoO3) Min 85% Insoluble in dil. NH4OH Max 0.01% Chloride (Cl) Max 0.002% Arsenate, phosphate & silicate (as SiO2) Max 0.001% Phosphate (PO4) Max 0.0005% Sulphate (SO4) Max 0.02% Heavy metal (as Pb) Max 0.003%