Towards a framework for life cycle thinking in the assessment of nanotechnology

The unique properties of nanomaterials and structures and also production technologies on the nanometer scale are associated with presumably revolutionary contributions to sustainable development in terms of resource efficiency or health care. The obvious benefits and potentials are currently neither substantiated by an assessment of ecological and human health risks nor by a holistic assessment of all aspects along the life cycle of nano based products and services. Little work has been done, so far, to compare, e.g., the efforts of material production and recycling with the benefits in the use phase beyond economic considerations. In order to ease the application of life cycle thinking in the nanotechnology domain functions, materials and impacts have to be described adequately. Due to the lack of relevant data and the heterogeneity of current life cycle based studies it is recommended to carefully adjust environmental prospects to the system under study. Regarding the life cycle performance of the materials used the efforts in realizing nano functionalities, properties and recycling gain decisive importance to counterbalance obvious advantages in the use phase. The assessment of potential risks for the environment and human health due to intended and also accidental releases are still not possible in LCA, but should nevertheless be supported by a thorough description of potential releases. All these observations are discussed by means of two case studies, one on PVD coating and one on a CNT-based FED screen in order to substantiate and illustrate the need for a framework to harmonise existing, ongoing and future LCA applications in this field. (c) 2007 Elsevier Ltd. All rights reserved.