Takeaway coffee cups release microplastics
University of Queensland research shows single-use paper cups with plastic linings release millions of microplastic and nanoplastic particles into hot
Single-use paper cups release millions of microplastic particles when used for hot beverages, according to new research from the University of Queensland. The study, published in August 2026 in ACS Food Science & Technology, found that cups lined with either fossil-based polyethylene (PE) or the biodegradable alternative polylactic acid (PLA) shed plastic into liquids.
Dr. Elvis Okoffo from UQ's Queensland Alliance for Environmental Health Sciences led the investigation. He stated that while both cup types released particles, PLA-lined cups released a total particle mass approximately 12 times higher than PE-lined cups. The nanoparticles released are around a thousand times thinner than a human hair.
Particle release from cup linings
The researchers measured the number of particles released when the cups were exposed to hot water. Their experiments yielded the following comparative figures:
| Cup Lining Type | Nanoparticles Released (per mL) | Relative Particle Mass Release |
|---|---|---|
| PLA (biodegradable) | Approximately 4.3 million | 12 times higher than PE |
| PE (fossil-based) | Approximately 2.7 million | Baseline |
Okoffo explained that a paper cup does not mean a plastic-free product. Many contain a thin plastic lining for water resistance and structural integrity. He said the study shows these linings release substantial quantities of micro- and nanoscale plastic material during everyday use.
Unclear health implications
Okoffo said the research contributes to evidence that new plastic food-contact products represent a significant source of human exposure via ingestion. He cautioned that the impact of these plastic particles on human health remains unclear. The chemicals in plastic are not meant to be consumed.
This does not mean people should necessarily stop using paper cups, or that PLA is inherently unsafe, according to Okoffo. He argued that materials need evaluation for both environmental sustainability and their particle-release behavior during use. The study aims to fill a knowledge gap about how single-use cups contribute to daily plastic exposure.
Calls for regulatory action
Okoffo called for consumers to be provided with information about the materials used to line paper cups. He suggested policymakers and regulators consider whether testing for micro- and nanoplastic release should form part of the safety assessment of food-contact materials, especially products for hot beverages.
Product manufacturers could consider developing cup linings that release fewer plastic particles when exposed to hot liquid, he said. Combining better product design, improved labeling, and public awareness could help limit the amount of plastic entering both human bodies and the environment. The research team's findings are now part of the growing scientific literature examining microplastic contamination from everyday items.
