The environmental costs of clean cycles: Quantitative analysis for the case of PVC window profile recycling in Germany

Abstract

Recycling schemes for long-lived products are challenged by the presence of “legacy substances,” which have been used in production in the past, but are nowadays classified as substances of concern. This study quantitatively evaluates the trade-offs between phasing out legacy substances, increasing circularity levels, and reducing life cycle impacts of polyvinylchloride (PVC) window profiles recycling in Germany based on a comprehensive dynamic material and substance flow analysis coupled with a prospective life cycle assessment. Scenario results indicate that although lead had been phased out in virgin PVC by 2015, lead concentrations in end-of-life PVC window profiles will remain above 0.3% until the end of the century without a restriction of lead in recycled PVC and will be by factor 3–5 higher compared to a restriction as stipulated by EU 2023/923. However, the latter is associated with lower recycling rates and higher life cycle environmental impacts of PVC window frame waste management, which cannot be fully compensated by the introduction of new waste treatment pathways using currently available technologies. The study serves to introduce a new comprehensive modeling framework, which allows for the consideration of trade-offs between substance, material, and environmental impact dimensions as a basis for discussing and developing sustainable waste management strategies.