Item name Country standard

Percent Superior grade First grade

Purity (Na2B4O7 .10H2O) % 99.5 min. 95.0 min.

Sodium carbonate % 0.1 max. 0.2 max.

Insoluble matters % 0.04 max. 0.04 max.

Sodium Sulphate % 0.20 max. 0.20 max.

Sodium Chloride % 0.03 max. 0.05 max.

Iron (Fe) % 0.002 max. 0.005 max.