Hot drinks in single-use paper cups shed millions of plastic particles, study finds
Researchers at the University of Queensland tested single-use paper cups lined with either polyethylene or polylactic acid. Both linings released micro- and nanoparticles when exposed to hot water, with the biodegradable PLA lining releasing about 12 times more particle mass. The health effects of ingesting these particles remain uncertain.
The study measured particle release when hot water contacted the cup linings. PLA-lined cups shed roughly 4.3 million nanoparticles per milliliter of liquid, while PE-lined cups released about 2.7 million particles per milliliter. These nanoparticles measure approximately one-thousandth the width of a human hair, making them invisible to the naked eye yet potentially significant in terms of cumulative exposure.
The findings appear in ACS Food Science & Technology and add to a growing body of research on food-contact materials. The researchers suggest regulators may consider whether particle-release testing should become part of safety assessments for products designed to hold hot beverages. They also note that manufacturers could explore alternative linings that shed fewer particles, and that clearer labeling could help consumers make informed choices.
Regular consumers of takeout coffee and tea could be unknowingly ingesting plastic particles with every hot drink, though the health consequences remain unclear. The study may prompt regulators to reconsider how food-contact materials are evaluated, potentially leading to new testing requirements or labeling standards. Manufacturers could face pressure to redesign cup linings, and consumers may become more cautious about single-use products marketed as biodegradable. The findings also highlight a tension between environmental sustainability claims and potential human exposure concerns that could influence future material choices across the food service industry.