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

Abstract

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.

Introduction

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. However, not all revolutionary changes are sustainable per se and a cautious consideration of benefits addressing not only economic prospects, but also social implications and environmental impacts are essential. Amongst other concerns potential impact mechanisms of molecular and atomic nanoparticles and structures are so far not well understood and difficult to investigate due to the complexities of these materials and compounds. Moreover, certain technologies and materials are shaping products and services already, therefore, life cycle thinking is becoming more and more important.

The economic relevance of nanotechnology as enabling technology relies on the opportunity to influence the properties of materials in a way that smaller but more capable and more “intelligent” system components with improved or new functionalities can be produced. Therefore, the competitiveness of companies and thus, of economies in the future may depend crucially on the ability to make use of nanotechnology. In various market studies a tremendous increase in sales volumes of nano markets is reported ranging between US$ 220 [1] and US$ 1000 billion [2] by 2010. Most important nano markets in 2001 were, according to Pridöhl [1], ultra thin layers with a share of 44%, ultra precise surface structuring (24%), and nanoparticles and nanocomposites (23%). As the importance of ultra thin layers and of ultra precise surface structuring will presumably fall to 37% and 22%, respectively, in 2010, the one of nanoparticles and nanocomposites will increase to 28%.

Corresponding to the expected development of nano markets the volume of research and development (R&D) expenditures increased accordingly. The nano R&D investments under the Framework programmes (FP) of the EU increased from € 120 million in the fourth FP (1994–1998) to € 1300 million in the sixth FP (2002–2006). A similar development could be seen in the USA [3].

According to a study of the EU Commission, public and private R&D expenditures world wide amount to about € 8 billion in 2004. Of these, about € 3 billion were disbursed in the USA, € 2.3 billion in Japan, and € 1.9 billion in the EU, summing up to about 87% of world wide R&D expenditures on nanotechnology [4].

The obvious benefits and potentials leading to such optimistic market behaviour and strategy setting in research and development 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. The assessment of risks and benefits in a life cycle perspective is necessary to detect possible short- and long-term adverse effects and to support decision making [5], [6].

As an objective of this paper, the authors examine the implications of life cycle thinking on nanotechnology and related market products. These implications are discussed from product, material and environmental perspectives and are illustrated by two case studies. The studies apply life cycle thinking in the nanotechnology domain and contribute to developing a common denominator framework for a consistent life cycle assessment in this field.