Caustic soda is one of the most widely usedchemicals. It is used to neutralize acids; tomake sodium salts; to precipitate metals astheir hydroxides; in petroleum refining; in thesaponification of esters; in the treatment ofcellulose, plastics, and rubber; and in numeroussynthetic and analytical applications.

Sodium hydroxide is sold commercially as anhydrous flakes or pellets or as 50% or 73% aqueous solutions. It has countless industrial uses and is one of the top 10 chemical in terms of production and use on a global scale. Approximately 15 million tons of sodium hydroxide is used annually. Its largest use, consuming about half of its production, is as a base in producing other chemicals. It is used to control pH and neutralize acids in chemical processes. The paper industry makes extensive use of sodium hydoxide in the pulping process. Sodium hydroxide is used to separate fibers by dissolving the connecting lignin. It is used in a similar fashion in the production of rayon from cellulose. Sodium hydroxide is a key chemical in the soap industry.In the saponification process, triglycerides obtained from animal and plants are heated in abasic solution to give glycerol and soap:

Sodium hydroxide is used in the textile industry for bleaching and treating textiles to makethem dye more readily. The petroleum industry uses sodium hydroxide in drilling muds and asa bactericide. Sodium hypochlorite (NaOCl) is used extensively for cleaning and as a disinfectant.Common household bleach consists of about 5% sodium hypochlorite solution. Sodiumhypochlorite is prepared by reacting chlorine with sodium hydroxide: Cl2(g) + 2NaOH(aq) →NaOCl(aq) + NaCl(aq) + H2O(l). Sodium hydroxide is used in the food industry for cleaningand peeling fruits and vegetables. Sodium hydroxide is a minor ingredient in many commonhousehold products, but in a few it may constitute more than half of the product. Dranocrystals contain between 30% and 60% sodium hydroxide and some drain cleaners can consistof 100% sodium hydroxide.