Polyethylene Terephthalate Oligomers in Disposable Diapers: Occurrence, Dermal Exposure and Health Assessment

Disposable infant diapers commonly use multicomponent nonwoven fabrics containing polyethylene terephthalate (PET), from which PET oligomer byproducts may be released and transferred to infant skin. In this study, 6 cyclic PET oligomers (C[TPA+EG]2–7) were detected in the top sheets and absorbent cores of 37 disposable diapers. ∑C[TPA+EG]2–7 averaged 198 ± 98.7 μg/g (top sheets) and 66.6 ± 49.2 μg/g (absorbent cores), dominated by C[TPA+EG]3 (95.9% and 92.3%). Oligomer levels positively correlated with diaper PET content, confirming an in situ polymer source. During a 3-day in-use study, 1348–2318 ng of oligomers migrated to infant buttock skin and remained partially after water washing, corresponding to an estimated C[TPA+EG]3 exposure of 8.80–182 ng/kg BW/day. Network toxicology and molecular docking identified potential targets and pathways associated with local skin effects, including inflammation, barrier regulation, apoptosis, and extracellular matrix remodeling, suggesting potential local skin-health implications. Our results establish diaper dermal contact as a critical infant plastic oligomer exposure route and raise health concerns for vulnerable infant skin.