Sodium hypochlorite is a chemical compound with the formula NaClO. It is composed of a sodium cation (Na+) and a hypochlorite anion (ClO−); it may also be viewed as the sodium salt of hypochlorous acid. When dissolved in water it is commonly known as bleach or liquid bleach. Sodium hypochlorite is practically and chemically distinct from chlorine. Sodium hypochlorite is frequently used as a disinfectant or a bleaching agent.

Sodium Hypochlorite is the main ingredient in laundry bleach. It is used extensively as a bleaching agent in the textile, detergents, and paper and pulp industries. It is also used as an oxidizing agent for organic products. In the petrochemical industry, sodium hypochlorite is used in petroleum products refining. Large quantities are also used as a disinfectant in water and wastewater treatment and sanitary equipment. In food processing, sodium hypochlorite is used to sanitize food preparation equipment, in fruit and vegetable processing, mushroom production, hog, beef and poultry production, maple syrup production, and fish processing.

In various parts of the world, sodium hypochlorite strength is identified using five common definitions that result in different numbers although the oxidizing power is the same, i.e., the sodium hypochlorite strength is the same.