Cas #: 1310-73-2, Caustic soda liquid is a solution of sodium hydroxide (NaOH) with water that reacts strongly with alkali and is obtained in most cases by electrolysis from sodium chloride. Caustic soda is applied in the synthesis of various chemicals (including sodium phosphate, formic acid). In large-scale chemical processes it is used, among other things, for the neutralization of acids. Due to its strong alkaline properties, caustic soda is also employed for cleaning processes including those in the food industry.