Nonylphenol ethoxylates toxicity

APEOs are used in domestic and industrial applications. They are applied as detergents, emulsifiers, wetting agents, dispersants or solubilisers. APEO derived from nonylphenol (NP), i.e. nonylphenol ethoxylates (NPEOs) comprises about 80% of the total market volume, while octylphenol-derived surfactants (OPEOs) account for 15-20%. Because of the persistence and toxicity of some degradation intermediates, their use has been reduced in several countries either through voluntary bans by the chemical industry or by legal regulations. However, excellent properties in combination with comparably low production costs hampers their complete replacement with other more environmentally acceptable alternatives. 

Ecotoxicological effects have been demonstrated for a number of surfactants or their metabolites, including some still currently in use, such as the nonylphenol ethoxylates [1], and as such there is a necessity to find more environmentally acceptable alternatives. Whilst the silicones are not the major surfactant type in use to date, the efficient properties and indications of low environmental persistence and toxicity demonstrate their potential for widespread use [2-4]. Relatively little is known about these new, rapidly emerging surfactants and the purpose of this chapter is thus to collate the available data, present new data, and identify the future research required in this area in order to evaluate the environmental relevance of this class of surfactants. 

This includes bioremediation cases of contaminated sites with several toxic and carcinogenic pollutants, such as petroleum hydrocarbons, PAHs, dichlorobenzene, chlorinated hydrocarbons, carbon tetrachloride, Dicamba, methyl bromide, trinitrotoluene, silicon-based organic compounds, dioxins, alkyl-phenol polyethoxylates, nonylphenol ethoxylates, and polychlorinated biphenyls. The following is a brief summary of each case. 

Nonylphenol ethoxylates (NPEOs) are extensively used as surfactants in industrial products (see Chap. 1). NPEOs are a mixture of polyethoxylated mono-alkylphenols, predominantly para-substituted, and are used in the manufacturing of paints, detergents, inks, and pesticides [435, 446]. Surfactants are common water pollutants because of their use in aqueous solutions, which are discharged into the environment in the form of wastewater from treatment plants or sludge stored in landfills. Degradation products of alkylphenol polyethoxylates, i. e., nonylphenol (NP), have the potential to be bioaccumulated, thereby becoming toxic to aquatic [447] and soil microorganisms [435,448]. 

These safer alternatives to nonylphenol ethoxylates degrade more quickly and completely to breakdown products of low toxicity. However, cost and performance are key limitations to substituting to NPE alternatives. Research into alternative surfactants may not be a priority for a company that already has a well-performing product,... 

The environmental campaign group said that 16 out of the 27 products from these brands were foimd containing toxic substances, including nonylphenol ethoxylates (NPEs). The highest concentration of NPEs was detected in a Louis Vuitton branded ballerina shoe. 

Octyl- and nonylphenol are well known raw materials used in the surfactant industry since the early 1960s, mainly for the production of their corresponding ethoxylated derivatives (APE). Today, these products have lost considerable importance in this industry as a consequence of substantial environmental threats, resulting from their relatively slow biodegradation, toxicity of their biodegradation metabolites and positive endocrine-disrupting reactions. 

This problem is essentially restricted to the alkylphe-nol ethoxylates (APEOs). Here, during biological degradation lower ethoxylated compounds, with one or two EO units, and nonylphenol are formed which are more toxic and additionally display undesired effects on the endocrine system. The opposite, for instance, is true for degradation products from LASs such as sulfopheno-lic fatty acids which display a highly reduced aquatic toxicity. 

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