Ethoxylated alcohols are a group of chemicals that are often used as detergents in personal care products. They are commonly labelled as polyethylene glycol (PEG) ethers and alcohols. The name can also include a number, which refers to the size of the chemical.
The aquatic toxicity of ethoxylated alcohols depends on the size of the chemical, but most are toxic to fish and aquatic invertebrates. The toxicity can be mitigated if the chemical is readily and completely biodegraded, which allows most of the chemical to be removed during wastewater treatment – before fish or aquatic invertebrates are exposed to it.
Some ethoxylated alcohols undergo ready and complete biodegradation, but others only undergo partial degradation. Partial degradation can result in the formation of another chemical that is just as toxic – if not more – than the original ethoxylated alcohol. Further, these chemicals can take a long time to degrade in the environment. This means that they have impacts over a longer period of time.
A good example of this is the case of nonylphenol ethoxylate, which is one type of ethoxylated alcohol. Nonylphenol ethoxylate is partially degraded in the environment to produce nonylphenol, or simple nonylphenol derivatives. Nonylphenol is highly toxic to aquatic life and has endocrine disrupting properties. Many governments have taken action to restrict the use of nonylphenol ethoxylates for this reason.