In life cycle assessments (LCA) involving materials recycling a method must be chosen for allocating processes and avoided emissions that is in line with the LCA’s goal and scope definition. This choice has a major influence on the results of the LCA for the product(s) in question. It is also a value choice, as there are no guidelines from the natural sciences. In this report, several arguments for opting for one of two approaches are discussed and applied to the case of metal packaging.
In the case of metals as packaging materials there are good reasons for preferring an end-of-life (EOL) approach from the perspective of promoting recycling and rewarding recycling efforts:
- there is no quality loss, so no effort is required to use secondary metals;
- the demand for secondary materials is high and will remain so in the foreseeable future;
- metal packaging has a short life span, guaranteeing that the secondary materials will indeed be used.
Certain redefined protocols may dictate adoption of a so-called ‘recycled content’ approach, on the argument that in the current structure of the secondary metals market boosting recycled content does not lead to avoided virgin production. For metal packaging it would be better to interpret the EOL recycling rate as an adequate substitute for the recycled content approach in such contexts as long as this recycling rate is guaranteed. In relation to the carbon footprint of metal packaging we conclude that recycling performance should be evaluated in terms of the EOL recycling figure (e.g. 85% in the Netherlands).