Understanding how chemical risk can be managed in a circular economy

• Chemicals in wastes can be a barrier for circular economy. • Assessing availability and effect of chemicals in reuse scenarios is key to safe reuse decisions. • Four key research themes are outlined to guide Australia’s management of waste chemicals. • An iterative approach to assess availability and effect of waste chemicals is proposed. Achieving a circular economy is dependent on our ability to safely reuse materials that would otherwise be classed as waste. This paper outlines challenges facing Australia in the context of international research trends for waste and waste reuse in a circular economy. Our understanding of the potential chemical hazards contained in our wastes and products with recycled content is a challenge due to the variability of waste and product materials. Such variability amplifies the need to ensure representative sampling to expand analytical and experimental methods and establish fundamental data and information related to chemical availability and ecological and human health effect. Four key themes are identified that need consideration, from identification of chemicals in our ever-diverse waste streams to dissemination of outcomes as guidance and for uptake in policy. Gaps in knowledge and the research required to address the four themes are outlined. The long-term development of an acceptable and consistent set of guiding principles related to the sampling, characterisation, categorisation and safe reuse of waste is shown to be important, further enabling resource recovery and reuse of materials.