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 toxic when undiluted (5% concentration as sold), but is rapidly diluted or decomposed to harmless levels in soil or sewage systems.
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. 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
In 2008, the Scientific Committee on Health and Environmental Risks (SCHER) for the European Commission concluded that the Risk Assessment Report (RAR) was of good quality, and agreed with its conclusions. No further study on human health is indicated. [2]