University of Queensland study finds paper cups release microplastics

A study from the University of Queensland has found that single-use paper cups release millions of microplastic and nanoplastic particles when they come into contact with hot liquids. The research, published in ACS Food Science & Technology, compared cups lined with fossil-based polyethylene (PE) against those lined with polylactic acid (PLA), a material often marketed as a biodegradable alternative.

While both types of cups release plastic particles, the PLA-lined cups released a total particle mass approximately 12 times higher than the PE-lined versions. Specifically, researchers detected about 4.3 million nanoparticles per milliliter in PLA-lined cups, compared to 2.7 million in PE-lined cups. These particles are approximately 1,000 times thinner than a human hair.

Lead researcher Dr. Elvis Okoffo noted that while the findings do not necessarily mean people should stop using paper cups or that biodegradable materials are inherently unsafe, the health impacts of ingesting these particles remain unclear. He emphasized that plastic chemicals are not intended for human consumption and called for better evaluation of particle release alongside environmental sustainability.