Mapping the chemical complexity of plastics.

Plastic pollution is a pervasive and growing global problem. Chemicals in plastics are often not sufficiently considered in the overall strategy to prevent and mitigate the impacts of plastics on human health, the environment and circular economy. Here we present an inventory of 16,325 known plastic chemicals with a focus on their properties, presence in plastic and hazards. We find that diverse chemical structures serve a small set of functions, including 5,776 additives, 3,498 processing aids, 1,975 starting substances and 1,788 non-intentionally added substances. Using a hazard-based approach, we identify more than 4,200 chemicals of concern, which are persistent, bioaccumulative, mobile or toxic. We also determine 15 priority groups of chemicals, for which more than 40% of their members are of concern. Finally, we examine data gaps regarding the basic properties, hazards, uses and exposure potential of plastic chemicals. Our work maps the chemical landscape of plastics and contributes to setting the baseline for a transition towards safer and more sustainable materials and products. We propose that removing known chemicals of concern, disclosing the chemical composition and simplifying the formulation of plastics can provide pathways towards this goal.