Many bleaches have strong bactericidal properties, and are used for disinfecting and sterilizing. Most bleaches are hazardous if ingested or inhaled, and should be used with care.

Other types of bleaches

Chlorine dioxide is used for the bleaching of wood pulp, fats and oils, cellulose, flour, textiles, beeswax, skin, and in a number of other industries.

In the food industry, some organic peroxides (benzoyl peroxide, etc.) and other agents (e.g. bromates) are used as flour bleaching and maturing agents.

Peracetic acid, ozone and hydrogen peroxide and oxygen are used in bleaching sequences in the pulp industry to produce totally chlorine free (TCF) paper.

Not all bleaches have an oxidizing nature. Sodium dithionite is used as a powerful reducing agent in some bleaching formulas. It is commonly used to bleach wood pulp used to make newsprint.

Human and environmental safety

Studies of human safety and environmental effects associated with household use of sodium hypochlorite bleach have been extensively documented. A review of these studies by the International Association for Soaps, Detergents and Maintenance Products (AISE) in 2007 confirmed that:

Human safety

• Neither carcinogenesis, mutagenesis, nor teratogenesis are indicated
• There may be minor, temporary effects such as localized skin and eye irritant (localized; potentially increasing with concentration, but this is unlikely to be significant at levels encountered in the household). There are no chronic effects, and while accidental acute effects can be painful, they are mostly reversible
• Hypochlorite imparts no systemic effects; it does not cause sensitization

Environmental impact

• No emissions of sodium hypochlorite from normal household or institutional use find their way directly to the environment. Sodium hypochlorite degrades quickly, primarily to sodium chloride, during use or in sewage systems. It also decomposes in soil, primarily to salt. Typical use was found to be not harmful to sewage treatment or septic tanks
• Sodium hypochlorite is practically non-toxic to birds and mammals.Fact: date=April 2009
• While highly toxic to fish and invertebrates in confined spaces, fish will swim away from the source if possible. In addition, sodium hypochlorite readily disperses and degrades mostly to salt in surface waters, limiting impact
• Very low levels absorbable organic halides (AOX) can be found during reaction of sodium hypochlorite and soils, including carbon tetrachloride, trihalomethanes (THM, such as chloroform), and trihaloacetic acid (THAA). Most AOX go into the sewer with wash water; amounts emitted to air well below safe limits. Most AOX degrades in sewage treatment like starting soil; wastewater genotoxicity not increased. Remnants are not harmful at levels detected (acute and chronic); no persistent or lipophilic chlorinated compounds were detected. Limited amounts of AOX have been detectable on fabrics below significant effect levels
• Bleach is not a source of dioxin, which only forms below pH 5 (at least 100 times lower than household applications). The risk of generating dioxin from use of household bleach is non-existent
• Chlorate ion can form during decomposition of sodium hypochlorite, but is readily decomposed during waste treatment
• Perchlorate can also form through decomposition; it is estimated that less than 5 ppb could be released in the wash, and less than 1 ppb could be found after dilution in waste treatment and septic systems. Most prevalent sources of perchlorate contamination in environment found to be blasting agents, military munitions, and fireworks. Massachusetts EPA concluded that normal household discharge of bleaches into municipal sewerage or conventional septic systems should not be an environmental issue