Takeaway Coffee Cups May Release Microplastics
Your takeaway coffee may come with an unexpected ingredient: microplastic particles. A new study by researchers at the University of Queensland has found that single-use paper cups can release millions of plastic particles when exposed to hot liquids.
Study Examines Paper Cups And Hot Drinks
Researchers from the University of Queensland’s Queensland Alliance for Environmental Health Sciences studied single-use paper cups used for hot beverages. The team examined cups lined with two different materials – fossil-based polyethylene, or PE, and the biodegradable alternative polylactic acid, or PLA.
Paper Cups Are Not Completely Plastic-Free
Although these cups are made largely from paper, many have a thin plastic lining on the inside. The lining helps prevent liquids from leaking through the paper and also gives the cup structural strength.
Researchers said the findings show that a paper cup should not automatically be considered plastic-free simply because most of its outer structure is made from paper.
Millions Of Plastic Particles Detected
The study found that both types of paper cups released plastic particles when exposed to hot liquid. However, the amount released varied depending on the lining material.
Researchers measured approximately 4.3 million nanoparticles per millilitre from PLA-lined cups, compared with around 2.7 million particles per millilitre from PE-lined cups.
Biodegradable PLA Lining Released More Particles
One of the key findings was that cups lined with PLA, which is marketed as a biodegradable alternative to conventional plastic, released significantly more particles than cups lined with polyethylene.
According to the researchers, the total particle mass released by PLA-lined cups was approximately 12 times higher than that of PE-lined cups in their experiments.
Nanoparticles Are Extremely Small
The particles detected in the study include nanoparticles that are extremely small around a thousand times thinner than a human hair.
Their tiny size makes them difficult to see with the naked eye and raises questions about how plastic particles released from food-contact materials may contribute to human exposure through everyday consumption.
Hot Liquid Is The Key Concern
The study specifically looked at what happens when hot liquid comes into contact with the lining of single-use paper cups. Coffee, tea and other hot beverages are commonly served in these cups around the world.
The findings suggest that the interaction between hot liquids and plastic-lined surfaces can lead to the release of micro- and nanoscale plastic particles.
Does This Mean Paper Cups Are Unsafe?
Researchers have cautioned against interpreting the findings as proof that people must stop using paper cups. Lead researcher Dr Elvis Okoffo said the results do not necessarily mean that consumers should avoid paper cups or that PLA is inherently unsafe.
The study instead highlights the need for more research into how particles released from food-contact materials behave and what their long-term effects could be.
Health Impact Of Microplastics Still Unclear
The researchers said the potential impact of these particles on human health remains unclear. The study demonstrates particle release, but it does not establish that consuming these particles from paper cups causes a specific disease or health condition.
This distinction is important as scientists continue to study the possible effects of microplastics and nanoplastics on the human body.
Researchers Call For Better Safety Testing
Dr Okoffo said materials used in food-contact products should be assessed not only for their environmental sustainability but also for how many plastic particles they release during everyday use.
The researchers suggested that testing for microplastic and nanoplastic release could become part of safety assessments for materials used with hot beverages.
Better Labelling Could Help Consumers
The research team also called for greater transparency about the materials used to line paper cups. Clear product information could help consumers understand whether a cup contains a plastic lining and what type of material has been used.
The researchers said better labelling, improved product design and greater public awareness could help reduce exposure to plastic particles.
Manufacturers Could Develop Safer Cup Linings
The study also points to a possible role for manufacturers in developing alternative cup linings that release fewer plastic particles when exposed to hot liquids.
Researchers said improving the design of food-contact products could help address both environmental concerns and questions about plastic exposure from everyday products.
Study Published In ACS Food Science & Technology
The research has been published in ACS Food Science & Technology, adding to a growing body of research examining the release of microplastics from disposable food and beverage containers.
What Takeaway Coffee Drinkers Should Know
The latest findings do not mean that every cup of takeaway coffee is dangerous. Instead, they highlight an often-overlooked issue with disposable paper cups: the paper itself may be combined with a plastic lining that can release particles when exposed to hot liquids.
For consumers, the study serves as a reminder that products labelled or perceived as “paper” are not necessarily completely free of plastic.
Microplastics In Everyday Products
The findings add to wider scientific concern about human exposure to microplastics and nanoplastics through everyday products. Disposable cups are used extensively for coffee, tea and other beverages, making them an important area for further research.
Scientists say more work is needed to understand how these particles behave after ingestion and whether long-term exposure has meaningful health consequences.
