A simple switch from a hot latte to an iced coffee could significantly reduce your daily intake of potentially harmful microplastics, according to a major new scientific review. The study, published on Monday 19 January 2026, confirms that temperature is a primary driver of microplastic release from common disposable containers.
The Heat is On: Temperature Drives Microplastic Shedding
Scientists assessed 30 published studies and conducted their own experiments, comparing the release of microplastic particles from common plastics like polyethylene (PE) and polypropylene (PP). The findings, published in the Journal of Hazardous Materials: Plastics, are stark. Hot food and drink can cause containers to release from hundreds to over eight million microplastic particles per litre.
"As the temperature of the liquid inside a container increases, the release of microplastics generally increases too," explained study author Xiangyu Liu. The research specifically found that for all-plastic PE cups, switching from cold to hot water increased microplastic release by about 33 per cent.
"If someone drinks 300 millilitres of coffee in a cup made of polyethylene per day, they could ingest 363,000 pieces of microplastic particles every year," Dr Liu stated, highlighting the scale of potential daily exposure.
Plastic vs. Paper-Lined: A Surprising Finding
The study also provided a direct comparison between different cup types. Researchers analysed around 400 coffee cups and discovered that PE-coated paper cups released fewer microplastic particles than pure PE plastic cups at both iced coffee (5°C) and hot coffee (60°C) temperatures.
While microplastic release from pure PE cups jumped by 32.7% with the temperature increase, this trend was not observed in the paper cups with a plastic lining. Advanced microscopic analysis revealed the reason: PE cups have a higher surface roughness, which appears to account for their greater shedding of tiny plastic fragments.
Health Implications and Practical Advice
This research arrives amid growing concern from the global scientific community. A mounting body of evidence links the daily ingestion of microplastics—particles sized from a thousandth of a millimetre to five millimetres—to potential health risks. These include hormone imbalance, diabetes, respiratory and reproductive issues, and an increased likelihood of several cancers.
The widespread use of single-use packaging is a key culprit, with an estimated 500 billion plastic cups used globally each year. The new findings offer clear, actionable guidance for consumers looking to minimise their risk.
The key practical insights are:
- Opt for cold beverages when using disposable plastic cups.
- Where possible, choose paper-based cups over all-plastic alternatives.
- Avoid using plastic containers for hot food.
The scientists conclude that their work provides essential evidence to support future regulatory efforts for safer consumer packaging, offering a direct path to reducing a significant source of microplastic pollution in our daily lives.
