Environmental risk limits for PFOS : A proposal for water quality standards in accordance with the Water Framework Directive
Milieurisicogrenzen voor PFOS
05 July 2012, PDF |
70 pages |
Moermond CTA, Verbruggen EMJ, Smit CE
RIVM Report 601714013
The National Institute for Public Health and the Environment (RIVM) has derived scientific Environmental Risk Limits (ERLs) for perfluorooctane sulfonate (PFOS) in fresh and marine surface waters. Measured concentrations in the Netherlands and other European countries exceed the ERLs for humans through fish consumption, as well as for water organisms and fish-eating birds and mammals. This indicates a potential risk for the water ecosystem. The risks for the average fish consumer are low because sufficient safety margins have been applied in the derivation. RIVM used the methodology as required by the European Water Framework Directive for the derivation of the ERLs in this report. ERLs are scientifically derived advisory values. They serve as a scientific background for the decisions to be taken at the national and European level, where other aspects will be taken into account as well. In the Netherlands, environmental quality standards are set by the Dutch Steering Committee for Substances, based on this advice and other considerations. The Dutch government uses environmental quality standards when implementing the national policy on substances. The MPC (maximum permissible concentration) is the level at which no harmful effects are expected, based on annual average concentrations. This MPC is based on three routes: direct ecotoxicity, secondary poisoning, and consumption of fish by humans. The lowest of these three routes determines the overall MPC. For PFOS, the consumption of fish by humans is the most critical route, which results in an MPC of 0.65 ng/L for freshwater. This route is based on a consumption of 115 grams of fish per day, which is seen as a conservative estimate. PFOS is a surfactant and is used in a variety of products such as fire-fighting foams, cleaners, adhesives and paper. Due to the physicochemical properties of PFOS, it does not degrade well and has been found to accumulate in biota, also in mammals even in remote areas. Production and use of PFOS are strongly restrained as a result of international regulations, with a complete ban as the ultimate goal. Restricted use of PFOS is allowed in a limited number of products for which it is deemed indispensible. Its use in these products will also eventually be phased out.