Start date: November 2013 - End date: April 2017
The GUIDEnano project generates a risk assessment web-based tool, which incorporates as well guidance on the selection of risk management options. To reach these goals, the project is building upon the state-of-the-art on risk assessment and management by validating critical assumptions in the risk assessment process, generating new predictive models, and novel risk management solutions.
Release and exposure evaluation
The GUIDEnano project categorizes the possible processes that take place during the different stages of a NM-enabled product life cycle. Default worse-case release values are assigned to these different processes that will be refined when specific models or experimental data are available for some of the processes. In order to generate release data during the use phase, methodologies will be identified or developed to simulate such types of processes in an accelerated manner. GUIDEnano will work on the adaptation of other standard methods or develop new aging devices to evaluate release and transformation of NM during other types of processes not yet considered in previous projects.
During experimental release evaluation, released NMs or the residues of degradation of the nano-enabled products, e.g. paint debris containing NMs, will be collected and a thorough physical-chemical characterization will be conducted.
Once the NMs are released to the environment, understanding their mobility and transformations during their environmental fate trajectory is critical to identify possible ecosystem effects, including long-term effects due to persistency or bioaccumulation. To this aim, the GUIDEnano project will identify the main processes that determine environmental fate and provide guidance to select the appropriate test methods. Among the parameters considered there will be solubility, dispersion stability in different aqueous matrices, mobility in soil/sediment matrices, and other transformation/degradation studies in different environmental matrices. A battery of experimental tests will provide model parameters to predict the transport of NMs in natural waters, sediments or columns of natural soils. Ultimately, these transport models will be used to identify environmental sinks of NMs and to estimate predictive environmental concentrations as well as the associated bioavailable NM-forms in each of the relevant environmental compartments at a local or regional scale.
Guidance will also be developed with the aim to help industrial partners identifying the toxicological tests to be conducted on a case by case basis, considering the relevant target communities, exposure routes, and exposure durations. Such tests will then be undertaken by the hazard assessment partners within the scope of the project, or could be undertaken by specialized CROs once the guidance is implemented beyond this project.
Most of the existing nanotoxicology studies have been conducted on pristine NMs. However, it is likely that consumers and workers in later stages of the life cycle are exposed to processed (e.g. coated) or aged NMs (recycling) rather than pristine NMs. Therefore, understanding the hazard of these exposure-relevant NMs is necessary for a meaningful risk assessment.
The risk mitigation strategies that the GUIDEnano project will generate and evaluate will range from the definition of best practices for handling NMs and NM-waste, to the evaluation of the efficiency of existing practices and the development of new control measures (PPEs, as well as air and water treatment), and the redesigning of NM towards a safer profile. These safer-by-design strategies will be developed to modulate the main factors determining safety of NMs: Intrinsic toxicity, release/ bioavailability potential, and persistence. Finally, suitable strategies for the end-of-life steps will be proposed in order to minimize the potential for occupational or environmental exposure, taking into account the features of different nano-enabled products.
Web-based risk assessment and risk management tool
The GUIDEnano Tool will be generated to incorporate the developed risk assessment strategies, scientific decision-trees, predictive models, data collection and evaluation templates, standardized methods, and databases, and other related technical information. The resulting GUIDEnano Tool will support end-users (e.g. industrial partners) during risk assessment and in the definition of effective risk mitigation plans for the effective application of the safety interventions. The GUIDEnano Tool will be iteratively improved during the project, incorporating new research findings and the feedback from the industrial partners.
Main steps in the development of the GUIDEnano Tool
A decision module that would either conclude on an acceptable level of risk, or on the contrary, would provide different options to refine the risk assessment (only in cases where a very conservative assessment was performed with large associated uncertainties) and/or to introduce risk mitigation measures. A sensitivity analysis of the risk assessment process would help to identify the step(s) of the risk assessment where refinement would be most cost-effective. Similarly, this decision node would guide in the selection of the most appropriate risk mitigation options for each particular case.
Risk assessment decision module
Efforts will also focus on evaluating the needs of key stakeholders (industry associations, regulators, consumers, insurers) in terms of the information needed in the risk assessment report. This will facilitate that the outcome of the GUIDEnano Tool is accepted by such stakeholders.