More than meets the eye: artificial eyelashes as an unrecognized source of microplastics and heavy metals

Despite growing concern over microplastic pollution, leave-on cosmetic products such as artificial eyelashes remain largely unexplored as sources of microplastics and associated contaminants. Here, nine artificial eyelash products were characterized for polymer composition, heavy metal content, and fiber release under simulated environmental conditions. Three polymers were identified: PBT (55.56%), PET (33.33%), and PVC (11.11%). Metal profiles varied widely across samples, with several metals of toxicological concern (Al, Ba, Co, Cr, Cu, Pb, Sb, Zn) detected but not declared on product labels. Sb concentrations in band-removed strip lash fibers reached 111.89 ± 6.55 µg/g, exceeding Health Canada’s cosmetic limit by >22×. Sediment-mediated mechanical abrasion generated substantial secondary microfiber release from cluster-style lashes, with increasing sand loading accelerating release kinetics. Up to ~50% of fibers were released within 24 h under medium–high abrasion, reaching 22,293 fibers/g at complete fiber release. A separate analysis of 19 top-selling online retail listings identified fiber counts of 1,800–20,000 fibers/pack, with sales-based extrapolation estimating annual emissions exceeding 2 billion microplastic fibers. Our findings identify artificial eyelashes as an overlooked source of primary and secondary microplastics and metal contaminants, underscoring the need for improved regulation and sustainable product design to reduce environmental and public health risks.