The impact of endocrine disrupting chemicals has been growing in recent years. These are chemicals which can mimic hormones and as such cause developmental problems and other diseases in animal systems.
Other chemicals known to have endocrine disrupting properties include bisphenol A (BPA) and phthalates. Currently there is much interest in another group of endocrine disrupting chemicals known as Nonyl phenol ethoxylates or NPEOs.
These are a group of man-made chemicals that do not occur in nature other then as a result of discharge to the environment. NPE’s are widely used as surfactants for both the textile and leather industry.
The damaging environmental effects of these chemicals has long been realised and as a result there have been various campaigns to highlight the environmental consequences of these chemicals, the most recent of which has been the Greenpeace dirty laundry campaign which has targeted global brands that have tested positively for NPEO in Greenpeace trials. (http://www.greenpeace.org/international/en/publications/reports/Dirty-Laundry-2/)
Alkylphenol ethoxylates (APEO) is the term used to describe the group of organic substances of which NPEO is one. These are mainly used as washing and cleaning agents (ie surfactants) and are used for textile and leather processing.
Whilst controls are in place within the European Union, the use of these chemicals in the rest of the world is largely unregulated, although there are EPA guidelines and regulations concerning the wider use of endocrine disrupting chemicals in the USA.
These chemicals are thought to persist in rivers and their sediments, and also are concentrated by wildlife, such as fish and birds, leading to contamination in their internal organs at much greater levels than in the surrounding environment.
Most significantly NPEO breaks down in the environment to the parent molecule NP (nonyl phenol). NP is persistent, bioaccumulative and toxic.
The most significant aspect of the effects of NPEO is that they are endocrine disrupting chemicals, that is they mimic oestrogens, hormones that are responsible for the development and maintenance of secondary sexual characteristics and behaviour.
It is known that compounds with oestrogenic effects disrupt the normal functioning of the hormone system, leading to potential reproductive problems. While there is more focus on legislation, the most challenging aspect of this problem is discovering how to eliminate these compounds from the environment and where to focus remediation efforts.
Even pollutants no longer in production persist in the environment, and bioaccumulate in the food chain. An understanding of how these chemicals, once in the environment, move through ecosystems, is essential to designing ways to isolate and remove them.
Working backwards through the food chain may help to identify areas to prioritise for remediation efforts. This may be extremely challenging for contaminated fish and marine mammals that have a large habitat and for those who consume fish from many different areas throughout their lives.
As an example, there have been reports of male rainbow trout being affected by oestrogenic compounds, whereby they are seen to produce a female egg-yolk protein.
The European Directive 2003/53/EC (amending the Council Directive 76/769/EEC) relating to the use of NP and NPEO is now in force. This applies within European communities to restrict the use of these compounds and has been in force since 2005.
The Directive states the following:
- (Nonylphenol and Nonylphenol ethoxylate) May not be placed on the market or used as a substance or constituent of preparations in concentrations equal or higher than 0.1% by mass for the following purposes:
Textile and leather processing except;
- Processing with no release to wastewater
- Systems with special treatment where the process water is pre-treated to remove the organic fraction completely prior to biological wastewater treatment (degreasing of sheepskins).
Other applications are also restricted by the legislation, including industrial cleaning, domestic cleaning, metal working, pulp and paper manufacture, cosmetics, personal care products, pesticides and biocides.
Furthermore, NPEO are listed as priority chemicals on the OSPAR Convention target list for ending discharges, emissions and losses of all hazardous substances (http://www.ospar.org/) and are also listed as a REACH Annex XV dossier, which is the regulatory instrument for the authorities or member states to propose and justify the identification of substances of very high concern or a proposed restriction. http://echa.europa.eu/chem_data/reg_int_tables/reg_int_en.asp?substance_type=Restriction&substance_state=current.
It is clear that there is no sustainable future for the use of these chemicals and alternatives must be sought. Fortunately for our industry, alternative cost effective surfactants are available based on ethoxylated alcohol or fatty alcohol chemistry as an example.