Environmental risk limits for ethyl-benzene and tributylphosphate in water : A proposal for water quality standards in accordance with the Water Framework Directive
Milieurisicogrenzen voor ethylbenzeen and tributylfosfaat in water : Een voorstel voor waterkwaliteitsnormen volgens de Kaderrichtlijn Water
26 May 2012, PDF |
35 pages |
Smit CE, Verbruggen EMJ
RIVM Report 601714019
RIVM has derived environmental risk limits (ERLs) for ethylbenzene and tributylphosphate in water. Both compounds are included in the Dutch decree on water quality objectives in the context of the Water Framework Directive (WFD). The standards have to be updated according to the current WFD-methodology. The values in this report serve as a scientific background for the Dutch Steering Committee for Substances, which is responsible for setting those standards. Monitoring data from 2010 indicate that the proposed standards will not be exceeded.
Proposed standards: The proposal for ethylbenzene is based on the European risk assessment report (EU-RAR) for this compound. According to the WFD, two different standards are proposed for fresh- and saltwater. The Maximum Permissible Concentration (MPC) is the level at which no harmful effects are expected, based on annual average concentrations. This MPC is derived for three routes: direct ecotoxicity, secondary poisoning, and consumption of fish by humans. The lowest of these values determines the final MPC (65 microgram per litre for freshwater and 10 microgram per litre for saltwater). The Maximum Acceptable Concentration (MACeco) is the concentration which protects ecosystems from effects of short term concentration peaks. MAC-values of 220 and 22 microgram per litre are proposed for freshwater and saltwater, respectively.
For tributylphosphate, updated MPC-values have been derived previously (66 and 6.6 microgram per litre for fresh- and saltwater). In addition, MAC-values of 170 and 17 microgram per litre are proposed for the respective water types.