Caustic Soda Flakes are the substance having the formula NaOH. these are inorganic substances also referred to as lye and caustic soda. The co; our of the substance are white, solid ionic substances made up of the cations sodium (Na) and the anions hydroxide (OH). At normal ambient temperatures, sodium hydroxide, a highly caustic base, and alkali breaks down proteins and can result in serious chemical burns. Caustic Soda Flakes are very water-soluble.