All Answers (6) Sodium hydroxide, NaOH, also known as lye or caustic soda, is an extremely caustic (corrosive and damaging to human tissue) white solid that readily dissolves in water. Sodium hydroxide is used in the manufacture of soaps, rayon, and paper, in petroleum refining, and in homes as drain cleaners and oven cleaners. Sodium hydroxide is one of the strongest bases commonly used in industry. Solutions of sodium hydroxide in water are at the upper limit (most basic) of the pH scale. Sodium hydroxide is made by the electrolysis (passing an electric current through a solution) of solutions of sodium chloride (table salt) to produce sodium hydroxide and chlorine gas.