Assay(acidimetric) min 99.0%Insoluble matter in H2O max 0.01%Chloride(Cl) 0.005%Sulphate(SO4) 0.01%Oxalate(C2O4) 0.035%Heavy metals(as Pb) 0.001%Lead(Pb) 0.001%Iron(Fe) 0.001%Zinc(Zn) 0.001%Arsenic(As) 0.0001%Calcium(Ca) 0.02%Barium(Ba) 0.002%Reaction against sulphuric acid passes testWater 7.5-8.8%Sulphated ash (6000C) 0.05%