Which compound is the main active ingredient in household bleach?

Sodium hypochlorite is the main active ingredient in typical household chlorine bleach.

Its formula is NaClO, often written NaOCl. In water, hypochlorite chemistry produces oxidizing chlorine-containing species that can destroy many colored molecules and damage microorganisms. This makes diluted bleach useful for disinfection and whitening.

Household bleach is a solution, not a bottle of pure sodium hypochlorite. Commercial products contain water and have carefully controlled concentrations. They should never be mixed with acids or ammonia-based cleaners, because dangerous gases or irritating vapors can form.

Sodium chloride is ordinary table salt and has a different formula, NaCl. Calcium hypochlorite is another chlorine-based disinfectant used especially in pools and water treatment, but it is not the usual active compound named for liquid household bleach.