Risk Assessment of PBDEs in the European Union – Process and Update Steven Eisenreich , Sharon Munn and Sazan Pakalin European Chemicals Bureau, Institute for Health and Consumer Protection, Joint Research Centre, Ispra, Italy 21024 Introduction: The EU Risk Assessment process under the existing substances legislation Regulation 793/93 will be described and an update of the conclusions of finalized and draft Risk Assessment Reports on various polybrominated diphenyl ether (PBDE) mixtures and products will be provided. Of special interest will be the re-assessment of the DecaBDE product due to the generation of new information. Background on EU Risk Assessment Process: The risk assessment carried out under Regulation 793/93 in the EU is conducted following the principles of the Regulation 1488/94 and the detailed methodology laid down in the Technical Guidance Document on Risk Assessment for New and Existing Substances (TGD). To assist Member States (MS) to implement the TGD and carry out risk assessments of individual priority substances, the European System for the Evaluation of Substances (EUSIS) was developed as a user friendly computer based system. The TGD and EUSIS together were developed by the European Commission directly with work groups from the EU MS, Industry and NGOs. The TGD was issued in four parts in 1996 with a strategy to continually update in accordance with available science and methodologies. The TGD was last revised in 2003. Scope: The scope of the RA covers emissions and consequent environmental impact and human exposures at each stage of the life-cycle of a priority substance from production, through processing, formulation, use and disposal. Protection goals are established for the environmental compartments - atmosphere, aquatic organisms, sediment and soil dwelling organisms, microorganisms in WWTPs, and mammals and birds exposed via accumulation in the food chain. Exposure of humans from all relevant sources is considered including exposure from consumer products and through air, food, and drinking water and the workplace. Each exposure scenario is assessed individually, and where appropriate, an overall combined exposure is also estimated. Risk Assessment Paradigm: The purpose of the RA is to determine the risk posed by a chemical or a chemical product, and the assessment of the risk is addressed by four steps 1) hazard identification, 2) dose-response assessment, 3) exposure assessment and 4) risk characterization. Hazard identification provides an indication of the adverse effect which a chemical has an inherent capacity to cause. A dose-response assessment is an estimation of the relationship between dose or level of exposure to the substance and the severity of an effect where appropriate. Exposure assessment is an estimation of the concentration/dose to which populations (workers, consumers, man) exposed indirectly through the environment or environmental compartments are or may be exposed. The estimation entails the determination of the sources, emission routes and degradation pathways of the chemical. Risk characterization is the estimation of the incidence and severity of the effects likely to occur in a human population of environmental compartment due to actual or predicted exposure to a chemical, and may include "risk estimation". Exposure Assessment: The exposure assessment methodology is designed to take a cautious reasonable worst case estimate of exposure where measured data are lacking, but there exists a scope to obtain such information. An extension of the environmental modeling also predicts the levels to which humans are exposed via air, drinking water and food thus providing an estimate of daily exposure of the effected human populations locally and regionally. Exposure data are frequently lacking so exposure models are often applied. Applying the EUSIS modeling framework, predicted environmental concentrations (PEC) locally and regionally in all environmental compartments are estimated.