The right recycling for a sustainable product. Today, mostly recycled material is used in castings. However, the number and proportion of impurities has increased since the 1950s and is expected to increase in the future. This is due to the fact that specifications and recycling are not sufficiently accurate and that today dilution of new material is used to achieve purity requirements. Previous studies have shown that the lack of accuracy has major consequences for productivity, but also jeopardizes a viable circular economy. In this demonstration project, we want to investigate the presence, origin and impact (environment and economy) of impurities in iron-based alloys. The project intends to specify limit values for critical contaminants, update material specifications and produce a recommendation about which products/materials should not be recycled to the selected applications. The project will carry out material analysers, machining analysers, LCA and perform industrial tests.