Minimum assay(GC) 99% Wt. per ml at 20oC 0.860-0.867g Refractive index 1.494-1.497 Maximum Limits of Impurities : Water 0.03% Acidity 0.012 ml N% Alkalinity 0.012 ml N% Non-volatile matter 0.002% Benzene(C6H6) 0.2% Copper(Cu) 0.00005% Iron(Fe) 0.0001% Lead(Pb) 0.00005% Organic impurities Passes acid wash test Sulphur Compounds(CS2) 0.0003% Thiophen homologues(C4H4S) 0.0002%"