End-of-life and waste management in life cycle assessment—Zurich, 6 December 2011

Waste management is a key component in society's strategy to mitigate the adverse effects of its economic activities. Through its comprehensive system approach, life cycle assessment (LCA) is frequently put forward as a powerful tool for the assessment of waste management activities. However, many methodological challenges regarding the environmental assessment of waste treatment systems still remain, and consensus is still far from being reached in areas like the definition of (temporal) system boundaries, life cycle inventory generation, selection and use of environmental indicators, and interpretation and communication of the LCA results.

The 46th Swiss Discussion Forum on Life Cycle Assessment (DF-46) consisted of three sessions. The first session tried to address policy making and implications for sustainable waste management of consumer products, e.g., information and communication technology, and food packaging. The second session focused on recent methodological developments in LCA for end-of-life treatment (EoL) activities and waste management assessment. The third session was dedicated to E-waste treatment and scarce metal recovery processes. DF-46 closed with short presentations on decision support in the areas of coprocessing, food waste, and after-treatment technologies for municipal waste incineration residues.

The main conclusions drawn from DF-46 are: (a) the option of waste prevention, despite its prominent position in the so-called waste hierarchy, is rarely considered in LCAs on waste and EoL management, (b) although a general problem in many other applications of LCA, the differences in scope definitions and time perspectives, the use of proxies or data of poor quality, allocation, or system expansion procedures, and weighting in the impact assessment are prominent issues in LCAs of waste and EoL management and thus have to be minimized and inventory data must be as transparent as possible, (c) life cycle inventory formats have to be adapted to be able to account for new materials, such as nanoparticles and scarce metals in LCA, (d) the selection of environmental indicators requires clear guidance on their appropriate use and open communication. The selection of a set of complementary indicators is of particular importance in order to avoid that the adverse effects on the environment are merely shifted between impact categories, and (e) useful LCA tools for the environmental assessment of waste management options are currently developed to meet the evolving demands and expectations for support in decision making related to waste and EoL management today and in the future. The presentations from DF-46 are available for download (www.​lcaforum.​ch).