APEs are poorly degraded during sewage treatment to products which are oestrogenic and toxic to wildlife. The Environment Agency is preparing an environmental quality standard (EQS) for nonyl phenol, one of the most well understood breakdown products, to protect wildlife in rivers receiving effluent discharges (ENDS Report 264, p 34 ).
According to the Agency, the EQS is likely to be set at 1µg/l as an annual average and a peak of 2.5µg/l. The figures are based on a "no observed effect" level of 20µg/l for water fleas.
Routine monitoring of APEs in the environment is unlikely to begin until a review of the Agency's monitoring strategy is completed next year. However, once monitoring begins it is likely to identify discharges from sources as diverse as engineering firms, leather and textile processors, car washes, tank cleaners and hospitals. The Agency may then require dischargers to reduce or phase out discharges as it did with the wool scouring industry in Yorkshire (ENDS Report 266, p 9 ).
A more powerful threat to the compounds may stem from a risk assessment conducted under the EC programme to evaluate the risks posed by older, "existing" substances. A study of nonyl phenol ethoxylates (NPEs) - the most widely used kind of APEs - is being conducted by the UK and is now approaching a final draft.
At an IBC conference in London in May, Dr Andreas Gies of the German Environment Agency revealed that the risk assessment has concluded that NPE releases from 21 of the 22 sectors studied resulted in environmental concentrations likely to harm wildlife. The ratio of predicted environmental concentrations (PECs) to predicted no effect concentrations (PNECs) varied from 0.81 to 2,021. "There is in my opinion a tremendous ecological risk," said Dr Gies.
Although groups such as the Soap and Detergent Industries Association have phased out APEs from domestic cleaning products and plan to do the same for industrial formulations by 2000, this is likely to be insufficient to deal with the risks uncovered by the assessment. The DETR is now considering potential measures to curb NPE discharges across a range of industries.
ENDS understands that a study for the DETR has found that voluntary measures across the EC have failed to reduce releases to the environment. Between 1994 and 1997, inputs of NPEs are believed to have increased by about 10%, with demand for the chemicals rising across all sectors. Restrictions under the 1976 EC Directive on marketing and use of dangerous substances are advocated by the study as the simplest and most effective means of controlling NPE discharges.
Such measures would not be popular with manufacturers because of reformulation costs. In a submission to the Environment Agency in May, the European chemical industry's organic surfactants group CESIO claimed that the cost of phasing out APEs would be close to £800 million. Most of the cost would fall on smaller firms. However, it is not yet clear whether any EC controls would apply to pesticides.