Legislation update

Citation

Geraghty, K. (2005), "Legislation update", Circuit World, Vol. 31 No. 3. https://doi.org/10.1108/cw.2005.21731cab.018

Legislation update

Legislation update

Nonylphenol ethoxylates (NPEs) have been used for over 50 years in a wide range of industrial processes and commercial products as surfactants, emulsifiers, wetting agents, detergents and dispersants. Historically, NPEs have found application in the printed circuit board (PCB) industry as surfactants in a number of process stages. However, concerns over their environmental fate and growing scientific evidence to support claims that NPEs are endocrine disrupters have resulted in the European Commission introducing a ban on their use, including their use in the PCB industry from the 17th January 2005.

The use of nonylphenols (NPs) and nonylphenol ethoxylates (NPEs) is to be banned in products which can result in discharges, emissions, or losses, to environmental media under a new EU Directive (2003/53/EC) which amends for the 26th time the Council Directive relating to the restrictions on the marketing and use of certain dangerous substances and preparations. The ban which came into force across EU Member States on the 17th January follows an earlier risk assessment by the UK's environment agency as part of the “existing substances” regime which highlighted concerns over the chemicals' toxicity to aquatic life and soil organisms. NP and NPEs were highlighted as substances of concern over a decade ago when they were placed on the “priority list” under the EU Programme for assessing the risks of “existing” chemicals.

Under the requirements of the Directive no person shall place on the market or use NP or NPEs as a substance or constituent of preparations in concentrations equal to or higher than 0.1 per cent by mass in the following applications:

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  industrial/institutional cleaning, except in closed dry cleaning systems where the washing liquid is recycled or incinerated;

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  domestic cleaning;

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  textile/leather processing;

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  metal working, except for controlled closed systems where the washings are recycled or incinerated;

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  pulp and paper manufacturing;

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  as an emulsifier in agricultural treatment dips; and

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  cosmetics and other personal care items except spermicides.

Whilst at first glance it may not be immediately apparent how the ban affects the PCB manufacturing process, the legislation does prohibit the use of NPEs in PCB fabrication. NPEs are non- ionic organic surfactants that belong to a class of compounds called alkylphenol ethoxylates. NPEs have a general formula of C₉H₁₉–C₆H₄0(CH₂CH₂0)_n H (Figure 1) where n represents a figure ranging from 1 to 100 with most commercially produced NPEs typically consisting of between 6 and 12 ethoxylate groups. Historically, NPEs have been used as surfactants in the electroless copper, alternative oxide and tin plating processes. To ensure compliance under the new regulations suppliers of process chemicals to board fabricators have developed appropriate and cost-effective substitutes.

Figure 1 The structure of nonylphenol ethoxylate (NPnEO)

The main concerns relating to the use of NPEs surround the environmental fate of their degradation products and the potential for bioaccumulation by other organisms. The main pathways for nonphenolic substances entering the environment are via industrial wastewaters and sewage discharges to surface waters. Additionally, NPs and NPEs have also been used as formulants in some pesticides and they may subsequently enter rivers and lakes as run-off following crop spraying. Whilst NPEs are readily degraded by bacteria at sewage treatment plants and upon entering the environment, the loss of ethoxylate groups to produce more persistent metabolites such as NP, nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO) and nonylphenoxy acetic acid (NP1EC) have been shown to pose a risk to aquatic life and soil organisms. An environmental risk assessment undertaken by the environment agency as part of the existing substances regulation (EEC 793/93) indicated that discharges of NPs and NPEs and the breakdown of NPEs to NPs pose a significant risk to the aquatic environment. NI are toxic to fish, aquatic invertebrates, and algae, they can affect plant growth and may impact on the mortality and reproduction of terrestrial invertebrates. Of even greater concern is the growing body of evidence to suggest that alkylphenol ethoxylates are endocrine disrupters. Suspicions first arose in the 1930s when Dodds and Lawson (1938) demonstrated the oestrogenic (oestrogen mimicking) affects of alkylphenol ethoxylates evidence. A claim that was further supported in a study by Mueller and Kim (1978) which demonstrated how a range of alkylphenols were capable of displacing and preventing the female sex hormone, oestradiol from binding to its receptor. The results of another study involving male rainbow trout placed close to the outfall pipes of sewage treatment plants showed the feminisation of the fish. Whilst it was believed this affect could be partly attributed to synthetic oestrogens used in the female contraceptive pill it is believed that these were not present in sufficient quantities and therefore, alkylphenol ethoxylates were also believed to have played significant role. There were numerous other studies over the years to support the claims that NP/ NPEs are endocrine disrupters. However, it is believed the introduction of the ban will reduce the environmental burden of NP/NPEs by 70 per cent because the remaining applications are less dispersive and therefore less of an environmental hazard.

The Directive has been transposed into UK law as the Controls on NP and NPEs Regulations 2004 (SI 2004 no. 1816). At the time of writing the Department of Environment, Food and Rural Affairs Defra, the Government Department responsible for implementing the legislation was drawing up enforcement plans. For further information on the NPE ban and how it may affect your operations contact your chemical supplier or Defra at: chemical.management@defra.gsigov.uk. or visit the Defra web site: www.defra.gov.uk/environment/chemicals/ukpolicy.htm

Kate GeraghtyIntellect

Note1. 2nd EU Lead-free Soldering Technology Roadmap, February 2003, Soldertec Global, available to download from information/ supply chain issues/roadmaps section of www.lead-free.org

Further readingMAFF (1994), Measurement of vitellogensis in male and female fish exposed to treated sewage effluents and river water.Warhurst, A.M. (1995), An Environmental Risk Assessment of Alkylphenol Ethoxylates and Alkylphenols.