Reusing materials is an attractive option for circular economy and can also reduce emissions of greenhouse gases and pollutants. However, recycling raises questions regarding the potential risks to human health or the environment when hazardous legacy chemical additives of materials are also recycled, instead of the recent and less hazardous additives of virgin materials. To address this trade-off, this study developed a model to calculate the total external cost of material supply, considering the health and environmental impacts of all industrial steps (e.g. virgin material production, incineration, and recycling), and the health effects of recycling chemicals present in the material. The model is coupling material flow analysis, life-cycle analysis, and environmental economics to compare different recycling policies. It is applied for all illustrative purposes to soft PVC and DEHP in France. Results show that recycling of materials is in the long-term positive despite the prolongation of the presence of hazardous additives in materials. The time when the recurring environmental benefits of recycling offset the negative impacts on human health of recycling the additives is very sensitive to the health impact of additives. This approach can improve the harmonization between recycling and circular economy policies, and as a framework to confirm the relevance and size treatments to remove additives from materials during recycling.
Keywords: PVC; Recycling; chemicals; environmental impacts; external cost; material flow analysis.