Assessing polylactic acid (PLA) fiber safety using underwear paddings as a model via nontargeted screening and...

Polylactic acid (PLA) fabrics made from PLA fibers are increasingly being promoted. However, the potential health risks of wearing PLA fabrics remain under explored. This study simulates the washing and drying cycles of underwear with PLA paddings and investigates the leaching of chemical additives in artificial sweat, with the aim of evaluating the exposure concentration levels of various additives in PLA fabrics during wear, subjected to different degrees of mechanical stress. Through nontargeted analysis, 70 chemicals were identified. The Toxicological Prioritization Index (ToxPi) was employed to score and rank the toxicity of these chemicals, parameters associated with skin stimulation were highlighted. Fourteen chemicals with higher toxicity scores and two phthalate esters (PAEs) as representatives of endocrine disrupting chemicals, were selected for quantitative analysis of leachates. The results indicated the presence of significant quantities of these chemicals in all samples, with total amounts ranging from 40.0 to 120 μg/g. The five chemicals with the highest leaching amounts-trifluoroacetic acid, tri-n-butyl phosphate, 2,6-di-tert-butylphenol, bis(2-ethylhexyl) phthalate, and 4-dodecylbenzenesulfonic acid-showed maximum leaching amounts of 51.2 μg/g, 49.6 μg/g, 26.1 μg/g, 16.7 μg/g, and 12.6 μg/g, respectively. Furthermore, considerable differences in exudation patterns were observed among the various chemicals. According to health risk assessment conducted by ToxPi, several chemicals have high toxicity weighted concentrations, suggesting the potential health risk of PLA fabrics. This study found that PLA fibers contain various toxic additives, and as the human body comes into more contact with PLA fibers, the exposure levels of these chemicals may pose health hazards and calls for a comprehensive evaluation of the environmental and health risks associated with PLA fiber products.