Screening and prioritization of endocrine-disrupting chemicals in plastic toys for children based on non-target analysis and machine learning predictive model

The health risks associated with the exposure of infants to harmful chemicals, particularly endocrine disruptors, in plastic toys have garnered widespread attention; however, the corresponding knowledge remains limited. In this study, we employed a non-target analysis approach alongside Toxicological Priority Index (ToxPi) model based on toxicity data predicted by machine learning predictive model to systematically screen and prioritize endocrine-disrupting chemicals (EDCs) in plastic toys for very young children (n = 45). A total of 165 compounds were identified and classified into five categories: additives (30.3 %), processing aids (13.3 %), monomers and intermediates of synthetic plastics (11.5 %), non-intentionally added substances (10.9 %), and uncategorizable chemicals (33.9 %). Among these, antioxidants, plasticizers, flame retardants, and surfactants were widely detected. Emerging non-phthalate plasticizers and non-intentionally added drugs were reported for the first time in this study. In addition to the known EDCs (e.g., phthalates), the endocrine disruption prediction results indicated that antioxidants (n = 8) and antibacterial agents (n = 2) exhibited high ToxPi scores among the identified chemicals. Further, exposure risk index was calculated by incorporating both ToxPi scores and the peak intensities of the compounds identified above. Toys made from polyethylene terephthalate, silicone, acrylonitrile-butadiene-styrene, and polystyrene had higher risk index compared with those made from polypropylene. The antibacterial agent ethyl sorbate, antioxidant Irganox 1010, therapeutics/prescription drugs dienogest, and antibacterial agent chalcone were identified as top priority EDCs in each material. This study highlights the urgent need to assess the exposure risks for infants through plastic toys and to implement control measures for emerging EDCs in plastic toys for very young children.