Regulatory applications of SSDs in European regulations

Paul Whitehouse
Environment Agency, UK

Regulatory frameworks like the Water Framework Directive (EC, 2000), Marine Strategy Framework Directive (EC, 2008), Plant Protection Products Directive (EC, 2009 and REACH (EC, 2006) are far-reaching pieces of legislation that require us to identify and manage pressures on the environment, including toxic chemicals. Assessing the hazard posed by chemicals is central to chemical risk assessment and also to the derivation of Environmental Quality Standards (EQSs).These play a key role in identifying risks and helping manage emissions to ensure wildlife and human health are not adversely impacted.

This presentation was in 2 halves. In the first half, I compared the approaches to setting environmental thresholds for chemicals in several European regulatory regimes. The comparison paid particular attention to the use of species sensitivity distributions e.g. the data requirements, use of other lines of evidence (e.g. field and mesocosm data) and use of assessment factors for dealing with residual uncertainty that remains after addressing interspecies differences in sensitivity. The second half of the presentation focused on the derivation and role of EQSs in the Water Framework Directive. There have been important technical developments in the derivation and application of EQSs in recent years, some of which have been captured in EU Technical Guidance (EC, 2011). Whilst deterministic methods for deriving EQSs remain the only option in some cases, SSDs are now the method of choice, including standards for bioavailable metals. I briefly reviewed the experience of EU Member States in using such approaches, the sources of variability that can give rise to different outcomes when different jurisdictions derive EQSs, and how different lines of evidence can be combined to derive EQSs. Finally, I suggested where further development in EQS derivation would be welcomed. For example, can we use SSDs to calibrate EQSs to the biological thresholds used within WFD to classify water bodies?