The Swiss Precautionary Matrix. The Swiss Precautionary Matrix was developed by TEMAS in Switzerland (Xxxx et al., 2008, 2010, 2011, 2013) for the Swiss Federal Council (FOEN) to assess health and environmental risks of nanoproducts. The tool provides advice on whether a precautionary approach is required under normal working conditions, worst case scenario and for the environment. A score is determined for each scenario which is a function of the scores assigned for ‘Nano-Relevance’ (N), ‘Potential Effect’ (W), ‘Potential Human Exposure/Potential Input into Environment’ (E), ‘Available Information on Life Cycle’ (I). The Precautionary Matrix contains two criteria for assessing nano-relevance. The first criterion is based on the EU proposed definition 2011/696/EU: “Manufactured materials are considered as nano-relevant if they comprise particles in the unbound state, as an aggregate or agglomerate and in which at least 50% of the particles in the number size distribution have one or more external dimensions in the range 1 to 100 nm. In the case that the number size distribution is unknown, specifically manufactured materials are considered nano-relevant if they have a specific surface/volume greater than 60 m. Fullerenes, graphene flakes and single wall carbon nanotubes are considered to be nanomaterials even when they exhibit dimensions of less than 1 nm.” The second being that nanospecific effects cannot be excluded even for particles > 100 nm as particles of up to ca. 300 nm can be taken up by organisms and cells (Xxxx et al., 2013). The Precautionary Approach definition is as follows: “Specifically manufactured materials are considered as nano-relevant which comprise particles in the unbound state, as an aggregate or agglomerate and in which one or more external dimensions are between 1 and 500 nm. Respirable materials up to 10 µm with nanoscale side branches can likewise trigger nanospecific effects and are likewise considered to be nano-relevant” The potential for causing health effects is determined based on the redox activity, catalytic activity and/or ROS (Reactive Oxygen Species)-formation (scored as 1 for those where the hazard is low, 5 for medium and 9 for high). This is then combined with the stability in the body or in the environment (assigned 1 for a short half-life (hours), 5 for a medium half-life (days/weeks) and 9 for a long half-life (months)) to derive an effect score for human or environment, respectively. Potential for exposure is determined by the amount of the ...
