Sodium hydroxide as NaOH, per cent by mass: Min. 99.50Chlorides as NaCl, per cent by mass: Max. 0.10Sodium carbonate as Na2CO3, per cent by mass, Max. 0.40Caustic soda flakes manufactured by us are free from foreign matter, dirt or other visible impurities. The product is widely used in the textile, soaps and detergents, pulp and paper industries and in alumina refineries.