Traditional risk assessment paradigms are challenged by the new properties of ENPs and new methodologies which need to be developed and applied. This goes for risk assessment methods for registration (prior to use) and for application (upon use). The overall aim of TP4 is to develop and apply risk assessment procedures and alternative decision support tools for nanomaterials both upstream (within the REACH frame, but not relying on existing technical guidance) and downstream (during and after product life)
In TP4 the results of TP1-3 are integrated in constructing a risk characterization schemes that ultimately is aimed at establishing the ratio between predicted environmental concentration (PEC) and predicted no-effect concentration (PNEC). In doing this, the relationships between biological endpoints and inherent properties like size, surface area, charge, solubility, crystal structure, surface chemistry, aggregation, associated contaminants/impurities, and chemical composition will be taken into account using data obtained in TP 1. Results generated in TP4 will also provide input to target the test development in TP2 and TP3. The environmental risk assessments procedures developed in TP4 will include consultation of producers and manufacturers as well as regulatory authorities. These evaluations are expected to provide valuable information for the comparison of the behaviour and ecotoxicity of nanoparticles with those of their chemical constituents or materials in other forms.
In this part of the project we will furthermore explore alternatives to risk assessment such as: Impact and alternatives assessment (Rossi et al. 2006), MultiCritieria Decision Analysis (Linkov et al. 2004, 2009), MultiCriteria Mapping (Mayer and Stirling 1999), Adaptive management (Holling 1978, 2001). Each of these tools will be evaluated against a set of criteria such as: applicability to inform decision-makers based on scarce pieces of information, information needed to use the tool with present knowledge, adaptability in the light of new information, burden of proof and finally, level of transparency.
The practical usability of the proposed frameworks in TP4 is of vital importance and will be tested through the completion of three case studies of gold, titanium dioxide, and nanosilver. These materials are used in a wide variety of settings (see Hansen et al. 2008) and the level of knowledge about their potential adverse effects as well as fate and behavior in the environment differ substantially, which should provide a good basis for testing and validating the applicability of the proposed framework. After completion of the case studies the framework will be revised in the light of the insight obtained through the actual use of the framework.