Environmental impact::Bleach


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Environmental impact A Risk Assessment Report (RAR) conducted by the European Union on sodium hypochlorite conducted under Regulation EEC 793/93 concluded that this substance is safe for the environment in all its current, normal uses.<ref>European Union Risk Assessment Report. 2007. Sodium Hypochlorite (CAS No: 7681-52-9; EINECS No: 231-668-3): Final report, November 2007 (Final Approved Version); see Risk Assessment Report on Sodium Hypochlorite, Scientific Committee on Health and Environmental Risks, 12 March 2008.</ref> This is due to its high reactivity and instability. Disappearance of hypochlorite is practically immediate in the natural aquatic environment, reaching in a short time concentration as low as 10−22 μg/L or less in all emission scenarios. In addition, it was found that while volatile chlorine species may be relevant in some indoor scenarios, they have negligible impact in open environmental conditions. Further, the role of hypochlorite pollution is assumed as negligible in soils.

Industrial bleaching agents can also be sources of concern. For example, the use of elemental chlorine in the bleaching of wood pulp produces organochlorines and persistent organic pollutants, including dioxins. According to an industry group, the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> However, respiratory risk from chlorine and highly toxic chlorinated byproducts still exists.

A recent European 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).<ref>Odabasi, M., “Halogenated Volatile Organic Compounds from the Use of Chlorine-Bleach- Containing Household Products”, Environmental Science & Technology 42, 1445–1451, (2008). Available at: Environmental Science & Technology (ACS Publications)</ref> These chlorinated compounds are emitted during cleaning applications, some of which are toxic and probable human carcinogens. The study showed that indoor air concentrations significantly increase (8–52 times for chloroform and 1–1170 times for carbon tetrachloride, respectively, above baseline quantities in the household) during the use of bleach containing products. 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. While the authors suggested that using these cleaning products may significantly increase the cancer risk,<ref>Odabasi, M., Halogenated Volatile Organic Compounds from the Use of Chlorine-Bleach- Containing Household Products, Slide presentation (2008)</ref> this conclusion appears to be hypothetical:

  • The highest level cited for concentration of carbon tetrachloride (seemingly of highest concern) is 459 micrograms per cubic meter, translating to 0.073 ppm (part per million), or 73 ppb (part per billion). The OSHA-allowable time-weighted average concentration over an eight-hour period is 10 ppm,<ref name="OSHA_CCl4">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> almost 140 times higher;

  • The OSHA highest allowable peak concentration (5 minute exposure for five minutes in a 4-hour period) is 200 ppm,<ref name="OSHA_CCl4"/> twice as high as the reported highest peak level (from the headspace of a bottle of a sample of bleach plus detergent).

Bleach sections
Intro   History    Mechanism of action  Classes of bleaches   Environmental impact    Disinfection   Color safe bleach   See also    References    Further reading    External links   

Environmental impact
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