Hypochlorites

Hypochlorites are salts or esters of hypochlorous acid, containing the hypochlorite ion (ClO−). The most common hypochlorites are sodium hypochlorite (NaClO) and calcium hypochlorite (Ca(OCl)2); lithium hypochlorite (LiOCl) is also used in some applications. In aqueous solution, hypochlorite is in equilibrium with hypochlorous acid (HOCl); the proportion of HOCl to OCl− depends on the pH of the solution. HOCl is generally a more effective disinfectant than the hypochlorite ion at near-neutral pH.

Production and chemistry: Industrially, hypochlorites are produced by reacting chlorine with alkali hydroxides, forming sodium hypochlorite solutions used in bleaching and disinfection. In the chlor-alkali process, chlorine is generated with NaOH, and subsequent reaction forms NaClO and NaCl. In water, hypochlorite is a powerful oxidizing agent; it slowly decomposes to chloride and oxygen, especially at higher temperatures or under light exposure. Acidification releases chlorine gas, a hazardous property to manage.

Uses: Hypochlorites are widely used as bleaching agents and broad-spectrum disinfectants. Household bleach is typically a sodium hypochlorite solution. They are employed in municipal water treatment, swimming pool sanitation, textile and paper bleaching, food processing sanitation, and healthcare settings for surface disinfection.

Safety and environmental considerations: Hypochlorites are corrosive and reactive oxidizers. They can release chlorine gas when combined with acids or reducing agents. They may form disinfection by-products when reacting with organic matter in water. Proper storage (cool, away from acids and organics) and handling are essential to minimize risks.