Life cycle assessment of manufactured nanomaterials: inventory modelling rules and application example

Abstract

Nanotechnology—sometimes designated as a ‘defining technology for the twenty-first century’—was first mentioned as a new field at the end of the 1950s in the famous speech by Richard P. Feynman (Feynman 1959). Two key characteristics of nanomaterials show up in the various developments in this area: the scale of the material and, related to this, its changes in properties and functionalities, but despite all these opportunities and the growing importance of nanotechnology, knowledge about the potential risks and hazards that may be linked to the various facets of this new technology is still incomplete. Using life cycle assessment (LCA) as a tool to address potential impacts on the natural environment and human health is a natural application of this methodology, both for the evaluation of manufactured nanomaterials (MNMs) and the products they are used in. However, so far, LCA has not been completely adopted for such a use. In fact, none of the public LCI databases contain a single data set for any type of MNM, despite the conclusions from an international workshop of LCA experts who consider LCA to be a suitable tool for an application in the area of nanotechnology (Klopffer et al. 2006). There have been a few examples of LCA studies published, but most of these studies are far from being comprehensive and complete LCA studies. These weak points, such as the lack of inventory data and missing characterisation factors, are at least partly due to a lack of clear modelling rules for a LCA of MNM, an issue that a recently finished PhD thesis of ETH in Zurich (Hischier 2013c) has taken up. The objective of this PhD work is the provision of the foundation for a clear guidance for coherent and comprehensive inventory modelling of nanomaterials along their complete life cycle. In order to achieve this objective, the thesis work consists of the following elements: