NaClO

NaClO, or sodium hypochlorite, is an inorganic compound that consists of a sodium cation and a hypochlorite anion. In practice it is most widely encountered as an aqueous solution used as a disinfectant and bleaching agent. Household bleach typically contains about 3% to 6% NaClO by weight, with higher-strength solutions used in industrial settings.

In solution, NaClO acts as a strong oxidizer. Its efficacy depends on pH: at lower pH it forms hypochlorous acid (HOCl), the principal disinfecting species, whereas at higher pH it exists mainly as the hypochlorite ion (OCl−). It is unstable and decomposes over time, especially in the presence of light, heat, or catalytic metals, to sodium chloride and oxygen. Concentrated solutions should be stored in opaque containers.

Production commonly occurs by the chlor-alkali process, where chlorine gas is reacted with sodium hydroxide or generated in situ by electrolysis of brine. A representative reaction is Cl2 + 2 NaOH → NaCl + NaClO + H2O. In water treatment and sanitation, NaClO is preferred for its broad-spectrum antimicrobial properties and decomposition to harmless salts.

Uses include disinfection of drinking water, swimming pools, and surfaces; sanitization in the food industry; and bleaching in paper, textiles, and household cleaning. It is also used as a deodorizer and in some wound-care products under controlled formulations.

Safety and handling require avoidance of mixing with acids or ammonia, which release toxic chlorine or chloramines. It is a strong oxidizer and can irritate skin and eyes; improper storage or disposal can impact the environment, particularly aquatic life. Environmental degradation typically yields chloride and chlorate species.