A surfactant is the part of a detergent mixture or a soap that does the actual work. Other compounds in the mixture provide support to the function of the surfactant, but the surfactant is the main mover and groover in the mix, let us say. In this article we will look at one particular surfactant - Alklyphenol ehoylate - and the practicality, safety and politics of its use here and in Europe.
According to an industry report (Mihaich, 2003), the nonionic surfactant Alklyphenol ethoylates are often referred to as the "workhorse surfactants" and are the preferred surfactant in many application because of their properties as outstanding dispersants, wetting agents and emulsifiers. They work well with little need for other additives.
From the point of view of American writers, the virtue of the use of these non-ionic surfactants is in that fewer chemicals are put into the environment when this particular surfactant is used. And, since these non-ionic surfactants are the most "studied" surfactant family available, their environmental impact and the limits within which they may be acceptably found present without causing damage to species appears to be well established. This means that monitoring the chemical in the environment is not such a challenge, as it is with less studied compounds.
Apparently, in the US, a number of studies have shown that sewage treatment plants remove on average 95% of nonylphenol and its ethoxylates from wastewater. The industry reports that studies have also shown that nonylphenol and nonylpnenol ethoxylates do not tend to bioaccumulate in the bodies of fish and in other animals. This would mean that they do not become a part of the food chain. Typical concentrations of NP/NPEs in the environment are below 1 ppb. (NP) is a minor degradation intermediate of nonylphenol. The report states that nonylphenol and octylphenol exhibit toxic effects on fish and invertebrates at concentrations above 1 microg/literand that nonylphenol has been found to have endocrine disrupting effects in freshwater organisms at concentrations of 20 microg/liter. The implication of this is that it is not of a concern since the detected levels fall within 'safe' limits (Mihaich, 2003).
Nonylphenol is favored by American detergent industries. Meanwhile, Europeans have banned the use of the nonionic surfactant nonylphenol - more on this below.
References:
Mihaich, E. et al; Relative Toxicity Ranking of Nonylphenol Ethoxylates and theirDegradation Intermediates to Estimate Cumulative Risk [Internet] Kansas City, MO: AOCS; May 7, 2003. Available from: (www.aperc.org.)
