Paper cups lined with plant-based plastic are often sold in coffee shops and cafeterias as an environmentally friendly option. But new research by scientists at the University of Queensland suggests these biodegradable cups may actually be worse than traditional cups when it comes to dropping tiny plastic particles into hot drinks.
S others. We demonstrated that biodegradable plastics can release nanoplastics during everyday use, highlighting a previously overlooked route of exposure for consumers. Image credit: Alexas Fotos.
Biodegradable plastics are increasingly being promoted as sustainable alternatives to traditional plastics.
However, the potential release of microplastics and nanoplastics during use remains poorly understood.
“Disposable paper cups are used daily by millions of people around the world for coffee, tea, and other hot beverages,” said study co-lead author Dr. Elvis Okofo.
“Just because a cup is mostly made of paper doesn’t mean it doesn’t contain plastic, because many contain a thin plastic lining that provides water resistance and structural integrity.”
“Our results show that plastic-lined paper cups release significant amounts of micro- and nanoscale plastic materials when exposed to hot water.”
In this study, researchers compared disposable paper cups lined with polylactic acid (PLA), a corn- or sugarcane-based plastic sold as compostable, to traditional polyethylene (PE)-lined cups.
They found that PLA-lined cups released approximately 12 times more plastic particle mass into hot water than polyethylene cups.
PLA cups release approximately 4.3 million nanoparticles per milliliter, while polyethylene cups release 2.7 million particles per milliliter.
Using a combination of advanced detection techniques, including mass spectrometry, light scattering analysis, and electron microscopy, the authors were able to confirm that the PLA lining released real nanoplastic particles in two size ranges roughly comparable to large viruses and small bacteria.
“This study contributes to the growing body of evidence that new plastic products used to store and prepare food are an important, but often overlooked, source of human exposure through ingestion,” Dr. Okofo said.
“This does not necessarily mean that people should stop using paper cups or that PLA cups are inherently unsafe.”
“However, the impact of plastic particles on human health is unknown, and we do know that the chemicals in plastics are not meant to be consumed.”
“Materials used in food contact products must be evaluated not only for environmental sustainability but also for particle release behavior during daily use.”
“This study fills an important knowledge gap about how disposable paper cups lined with plastic materials contribute to daily plastic exposure.”
“Consumers should be provided with information about the materials used to line paper cups, and regulators are urged to consider safety guidelines and warnings on product labels.”
“Policymakers and regulators could consider whether testing for micro- and nanoplastic emissions should be part of the safety assessment of food-contact materials, especially products designed for hot drinks.”
“Product manufacturers could also consider developing cup linings that release less plastic particles when exposed to hot liquids.”
“Through a combination of better product design, improved labeling, and public awareness, we can limit the amount of plastic that enters both our bodies and the environment.”
of result appear in the diary food science and technology.
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Ke City others. Nanoplastics and microplastics are released from disposable paper cups lined with polyethylene and polylactic acid. ACS Food Science. technologypublished online on August 25, 2026. doi: 10.1021/acsfoodscitech.6c00541
Source: www.sci.news
