ITEM INDEX Purity ( GC) % 99.95 MIN COLOR Hz 10 units Specific Gravity ( kg/ m3) 20° C 1.042 - 1.052 Refraction index 1.538-1.542 Benzal Dehyde % 0.1 MAX Dibenzyl Ether 500 ppm MAX Clarity of solution Clear ( 1+ 30) Chloride % 0.005 MAX Moisture % 0.1 MAX Residue after Ignition 0.005% MAX Non-Volatile Residue 0.05% MAX Acidity ( Benzoic Acid) % 0.1 MAX