Bleach

Bleach is a chemical product used to whiten or remove color from fabrics, surfaces, and water by chemical oxidation. Household bleach typically refers to an aqueous solution of sodium hypochlorite, commonly around 3 to 6 percent available chlorine. Other bleaching agents include calcium hypochlorite (bleaching powder), hydrogen peroxide, and sodium chlorite, as well as oxygen-based bleaches such as sodium percarbonate. These products vary in strength, pH, and intended use.

Bleaching works by oxidizing pigments and organic stains, breaking down colored compounds. In water treatment and disinfection, hypochlorite compounds also inactivate many bacteria, viruses, and some fungi. Effectiveness depends on concentration, temperature, contact time, and the presence of organic matter; performance can decline at high pH.

Common uses include whitening and stain removal in laundry, sanitizing kitchen and bathroom surfaces, and treating water in pools and drinking-water facilities. Industrial applications include pulp and paper bleaching, textile processing, and equipment sanitation. Bleach products are often chosen for rapid action and broad-spectrum efficacy, but their chemistry and compatibility with materials vary.

Safety considerations are important. Bleach is corrosive and can irritate skin, eyes, and the respiratory tract. Do not mix bleach with acids or ammonia, as chlorine gas may be released. Use in a well-ventilated area, wear appropriate protective equipment, and store containers away from heat and out of reach of children.

Environmental and health considerations include the potential formation of harmful chlorinated byproducts if released untreated into the environment. Disposal should follow local guidelines. The development of bleaching technologies has evolved from calcium hypochlorite powders to stable sodium hypochlorite solutions and alternative oxidizers.