Eco-Efficiency Indicators for Metals A Systematic Exploration Only if we can precisely measure a product or service’s impact, can we work towards a reduction of that impact. Therefore, in order to increase the sustainability of consumption and production it is necessary to develop sound methods to measure environmental impacts along product value chains. Public perceptions of the eco-efficiency performance of products are often focussed on the most visible life-cycle phases and only the most direct impacts. These perceptions can be misleading and can motivate efforts to focus on certain stages of the value chain while potentially neglecting other areas that may be of greater importance. In the case of metals, emphasis often lies on the impacts arising in production and processing despite the fact that the use of metals can, in some cases, lead to increases in overall life-cycle eco-efficiency. One example is the metal aluminium, which is very energy intensive in the production phase. Despite this drawback, significant fuel savings can be achieved through the application of lightweight aluminium in vehicles. Furthermore, considering the lifecycle perspective, aluminium is very attractive, because the metal can be recycled with just 5% of the energy required for primary aluminium production. Indicators for the Impact and Added Value of Metals The project Eco-Efficiency Indicators for Metals (EIM) developed methods to assess environmental impacts and the added value of a variety of metals in selected products. The objective was to provide a scientific and stakeholder-based assessment that includes both value added sustainability benefits as well as negative impacts. The project was based on a study that surveyed four metals applications: aluminium in cladding, nickel in batteries, copper in motors, and zinc in gutters. The selected cases cover a broad range of eco-efficiency aspects within the relevant application fields. With the help of these practical examples, gaps in stakeholder perceptions of eco-efficiency for the four metals were identified and perception gaps for metals in general were extrapolated. The Life Cycle Approach: Identifying Hot Spots The lifecycle of metals can be divided into six phases: Resource extraction, extractive metallurgy, processing, logistics, use phase and recycling, each of which presents specific eco-efficiency challenges and opportunities. It is essential to identify the life-cycle phases with the highest environmental impacts, the so called “hot spots”. The project’s outcome was a flexible toolbox that can be applied to a number of different metals and which reveals the eco-efficiency performance over the entire life cycle. This enables comparability and helps to identify joint actions and areas for stakeholder outreach and cooperation for future sustainability efforts of the metal industry. The CSCP carried this project together with the Wuppertal Institute for Climate, Energy, Environment and in collaboration with the European Association of Metals (Eurometaux), representing the metal industry to deliver this project.