A new study has found that hot beverages in paper cups can release massive amounts of microplastics within just 15 minutes.
Researchers at the Indian Institute of Technology (IIT) recently published findings in the Journal of Hazardous Materials warning of health risks associated with paper cup use.
The research team poured hot liquid at 85-90 degrees Celsius into paper cups and left them for 15 minutes. The results confirmed that the polyethylene coating applied inside paper cups becomes damaged by high temperatures, releasing large quantities of microplastics.
The numbers were significant. An average of 25,000 microplastic particles were detected per 100 milliliters of beverage.
More concerning was the finding that approximately 10.2 billion nanoplastics—too small to see with the naked eye—were present.
The plastic coating layer applied inside paper cups during manufacturing to prevent liquid penetration was identified as the cause. While appearing capable of withstanding high temperatures, the coating deteriorates faster with prolonged exposure to hot liquids. This process can release not only microplastics but also harmful chemicals and heavy metals including ions, fluoride, and sulfates, according to the analysis.
The extremely small size of released micro- and nanoplastics makes them relatively easy to absorb into the body, researchers noted. The particles can penetrate into the body through blood circulation. Long-term accumulation may risk disrupting the immune system or causing hormonal abnormalities.
Experts emphasized that public perception of paper cups as a safer alternative to plastic cups needs to change. Drinking two to three cups of coffee daily from paper cups could result in consuming trillions of nanoplastic particles annually, they warned.
Experts advise drinking beverages as quickly as possible for healthier coffee habits. Using personal tumblers made of stainless steel or glass is also recommended.
