IN time for the fourth session of the Intergovernmental Negotiating Committee (INC) to develop an international legally binding Global Plastics Treaty, a team of researchers put together 'PlastChem: State of the Science on Plastic Chemicals,' a comprehensive report on chemicals used and found in plastics. About 4,200 of the 16,000 chemicals identified were flagged as 'chemicals of concern' due to toxicity, persistence, bioaccumulation and/or mobility.