An engineered nanomaterial (ENM) may actually consist of a population of primary particles, aggregates and agglomerates of various sizes. Furthermore, their physico-chemical characteristics may... Show moreAn engineered nanomaterial (ENM) may actually consist of a population of primary particles, aggregates and agglomerates of various sizes. Furthermore, their physico-chemical characteristics may change during the various life-cycle stages. It will probably not be feasible to test all varieties of all ENMs for possible health and environmental risks. There is therefore a need to further develop the approaches for risk assessment of ENMs. Within the EU FP7 project Managing Risks of Nanoparticles (MARINA) a two-phase risk assessment strategy has been developed. In Phase 1 (Problem framing) a base set of information is considered, relevant exposure scenarios (RESs) are identified and the scope for Phase 2 (Risk assessment) is established. The relevance of an RES is indicated by information on exposure, fate/kinetics and/or hazard; these three domains are included as separate pillars that contain specific tools. Phase 2 consists of an iterative process of risk characterization, identification of data needs and integrated collection and evaluation of data on the three domains, until sufficient information is obtained to conclude on possible risks in a RES. Only data are generated that are considered to be needed for the purpose of risk assessment. A fourth pillar, risk characterization, is defined and it contains risk assessment tools. This strategy describes a flexible and efficient approach for data collection and risk assessment which is essential to ensure safety of ENMs. Further developments are needed to provide guidance and make the MARINA Risk Assessment Strategy operational. Case studies will be needed to refine the strategy. Show less
Oomen, A.G.; Bleeker, E.A.J.; Bos, P.M.J.; Broekhuizen, F. van; Gottardo, S.; Groenewold, M.; ... ; Landsiedel, R. 2015
Physicochemical properties of chemicals affect their exposure, toxicokinetics/fateand hazard, and for nanomaterials, the variation of these properties results in a wide variety ofmaterials with... Show morePhysicochemical properties of chemicals affect their exposure, toxicokinetics/fateand hazard, and for nanomaterials, the variation of these properties results in a wide variety ofmaterials with potentially different risks. To limit the amount of testing for risk assessment,the information gathering process for nanomaterials needs to be efficient. At the same time,sufficient information to assess the safety of human health and the environment should beavailable for each nanomaterial. Grouping and read-across approaches can be utilised tomeet these goals. This article presents different possible applications of grouping andread-across for nanomaterials within the broader perspective of the MARINA RiskAssessment Strategy (RAS), as developed in the EU FP7 project MARINA. Firstly,nanomaterials can be grouped based on limited variation in physicochemical properties tosubsequently design an efficient testing strategy that covers the entire group. Secondly,knowledge about exposure, toxicokinetics/fate or hazard, for example via properties suchas dissolution rate, aspect ratio, chemical (non-)activity, can be used to organise similarmaterials in generic groups to frame issues that need further attention, or potentially toread-across. Thirdly, when data related to specific endpoints is required, read-across can beconsidered, using data from a source material for the target nanomaterial. Read-acrosscould be based on a scientifically sound justification that exposure, distribution to thetarget (fate/toxicokinetics) and hazard of the target material are similar to, or less than, thesource material. These grouping and read-across approaches pave the way for better use ofavailable information on nanomaterials and are flexible enough to allow future adaptationsrelated to scientific developments. Show less
Peijnenburg, W.J.G.M.; Baalousha, M.; Chen, J.; Chaudry, Q.; Kammer, F. von der; Kuhlbusch, T.A.J.; ... ; Koelmans, A.A. 2015
Proper understanding of the basic processes and specific properties of engineered nanomaterials (NMs) that modify the fate and effects of NMs is crucial for NM-tailored risk assessment. This in... Show moreProper understanding of the basic processes and specific properties of engineered nanomaterials (NMs) that modify the fate and effects of NMs is crucial for NM-tailored risk assessment. This in turn requires developers of NMs and for regulators to consider the most important parameters governing the properties, behavior and toxicity of NMs. As fate and effect studies are commonly performed in laboratory settings, mimicking to a varying extent realistic exposure conditions, it is important to be able to extrapolate results of fate and effect studies in synthetic media to realistic environmental conditions. This requires detailed understanding of the processes controlling the fate and behavior of NMs in terrestrial and aquatic media, as dependent on the composition of the medium. It is the aim of this contribution to provide background reading to the NM and media specific properties and processes that affect the fate and behavior of NMs in aquatic environments, focusing on the specific properties of NMs that modulate the interactions in the aquatic environment. A general introduction on the dominant fate determining processes of NMs is supplemented by case studies on specific classes of NMs: metal NMs, stable oxides, iron oxides, and carbon nanotubes. Based on the synthesis of the current knowledge base toward essential data and information needs, the review provides a description of the particle specific properties and the water characteristics that need monitoring in order to allow for future quantification and extrapolation of fate and behavior properties of NMs in freshwater compartments of varying composition. Show less
