Caustic Soda Flakes, specially appears as White or nearly white pellets, flakes, sticks, fused masses. In addition,Lye is clear or slightly turbid, colorless or slightly colored, strongly caustic and hygroscopic and when exposed to the air they absorb carbon dioxide (CO2), forming sodium carbonate. Caustic soda flake is mostly uses as industrial raw material. Chemical industry uses around 56% of Sodium Hydroxide, while the paper industry uses 25% of the same total. This Caustic Soda Flake (NaOH) is often as liquid, for handling easier also cheaper price. Sodium Hydroxide solid also used for production of sodium salts and detergents, for organic synthesis, and for pH regulation. It uses in Bayer process of aluminum manufacture. Also, crude oil with poor quality can be treated with caustic soda flake to remove sulfurous impurities in one process known as caustic washing. As above, reaction between Caustic Soda Flake (NaOH) with weak acids like mercaptans and hydrogen sulfide to give removable non-volatile sodium salts. Then, it forms waste such as toxic, which is difficult to deal with. Produced NaOH by membrane cell process, typically brought up as Membrane Grade.