The presence of other organic matter in the place of application can make these disinfectants less effective, by consuming some of the released chlorine.
[3] Chlorine-based bleaches have been used since the late 18th century to whiten cotton and linen clothes, removing either the natural fiber color or stains of sweat or other organic residues.
[9] Due to transport and handling safety concerns, the use of sodium hypochlorite is preferred over chlorine gas in water treatment.
[10] Chlorine releasing compounds can react with other common household chemicals like vinegar or ammonia to produce toxic gases.
The hypochlorite anion and chlorine are in equilibrium in water; the position of the equilibrium is pH dependent and low pH (acidic) favors chlorine,[11] A hypochlorite bleach can react violently with hydrogen peroxide and produce oxygen gas: A 2008 study indicated that sodium hypochlorite and organic chemicals (e.g., surfactants, fragrances) contained in several household cleaning products can react to generate chlorinated volatile organic compounds (VOCs).
The increase in chlorinated volatile organic compound concentrations was the lowest for plain bleach and the highest for the products in the form of "thick liquid and gel."
The significant increases observed in indoor air concentrations of several chlorinated VOCs (especially carbon tetrachloride and chloroform) indicate that the bleach use may be a source that could be important in terms of inhalation exposure to these compounds.
Chronic exposure, for example, from the air at swimming pools where chlorine is used as the disinfectant, can lead to the development of atopic asthma.
[citation needed] The extensive reactivity of chlorine is also responsible for its broad antimicrobial effect, since it can destroy or denature many proteins and other chemicals that are essential for microbes' metabolism.
[24][25] The strength of commercial chlorine-releasing products may be instead specified as the concentration of the active ingredient, as mass or weight percent or grams per liter.
In order to determine the free chlorine content of the product, one must take into account the oxidizing reactions that the ingredient may undergo in the application.
[24] Swedish chemist Scheele discovered chlorine in 1774,[26] and in 1785 French scientist Claude Louis Berthollet recognized that it could be used to bleach fabrics.
[27] His work greatly improved medical practice, public health, the sanitary conditions in hospitals, slaughterhouses, and all industries dealing with animal products—decades before Pasteur and others established the germ theory of disease.
[28] In particular, it led to the nearly universal practice of chlorination of tap water to prevent the spread of diseases like typhoid fever and cholera.
[29][6] In 1915, British chemist Henry Dakin, working at a field hospital in France during World War I, did an extensive study of compounds that could be used to disinfect wounds and prevent sepsis.
He found that chloramine was optimal, but settled for a dilute sodium hypochlorite solution—still used today with the name of "Dakin's solution"—for reasons of cost and availability.