PRIO – A tool for Risk Reduction of Chemicals

Alkylphenols and their derivatives

In general, alkylphenols are chemical compounds that consist of one or more alkyl chains bound to a phenol. Phenol consists of an aromatic ring and a hydroxyl group.

The alkyl chain may be of differing length, e.g. butyl, nonyl or dodecyl have four, nine and twelve carbon atoms respectively. The Swedish Chemicals Agency has drawn up substance information and has made flow analyses for a large number of alkylphenols and their derivatives, including nonylphenol, dodecylphenol and nonylphenol ethoxylates. Here you can search for flow analyses.

Alkylphenols are used to prepare derivatives, e.g. alkylphenol ethoxylate. Alkylphenol ethoxylate is prepared by a chemical reaction between alkylphenol and oxirane. Alkylphenol ethoxylates are surface-active substances that are used, for instance, in cleaning products.

The majority of all nonylphenol produced is used for the manufacturing of nonylphenol ethoxylate. However, the use of nonylphenol ethoxylate decreased in Sweden during the 1990s. Link to brief statistics on Nonylphenol ethoxylate. Nonylphenol is also used as a catalyst in the hardening of epoxy resins. Dodecylphenol is used for the manufacturing of lubricant additives and for the preparation of dodecyl ethoxylate.

Nonylphenol ethoxylate is broken down relatively readily in the environment, with the formation of nonylphenol as a breakdown product. Nonylphenol is persistent and bioaccumulative in the environment. Many alkylphenols are toxic to aquatic organisms, and the most toxic are those with a large alkyl chain, i.e. octyl-, nonyl- and dodecylphenol. Nonylphenol is classified as very toxic to aquatic organisms and can cause long-term adverse effects in the environment, here you can search in the classification list. Here you can search in the Classification list.

Nonylphenol has also been found to have oestrogenic effects, and feminisation of male fish has been observed. A risk assessment of octylphenol is also in progress in the EU (Existing Substances Programme). Data in the risk assessment suggest that octylphenol has the same properties as nonylphenol with regard to both environmental hazard and oestrogenic effects.

Nonylphenol and nonylphenol ethoxylate are prohibited in certain areas of use in the EU.

Further information:

Risk assessment of Alkylphenol and Alkylphenol Ethoxylate Exposure, with Focus on Octylphenol and Butylphenol. KemI Report 1/00, Swedish Chemicals Agency 2000.

European Union Risk Assessment Report 4-nonylphenol (branched) and nonylphenol Risk Assessment. European Communities, 2002.