Study shows boiling in plastic kettles leaches nano and microplastics into liquid
Last update on Dec 3, 2025
Researchers have called for consumer warnings on plastic kettles after finding nano and microplastic particles leach into the liquid.
Dr. Elvis Okoffo from The University of Queensland’s Queensland Alliance for Environmental Health Sciences said the first few boils in a new kettle showed the highest levels of plastic, though particles were still detected even after 150 uses.
First 150 boils release notable concentrations
The research found the first boil in a new kettle released almost 12 million nanoparticles per milliliter– equating to almost 3 billion particles in an average 250ml cup of tea. After 150 boils, there were still 820,000 nanoparticles detected per milliliter, or 205 million per 250ml cup.
“Boiling water in plastic kettles is a daily routine for millions of people worldwide and we have found this simple habit can release tiny plastic particles into the water we use every day," Dr. Okoffo said. “This study provides evidence that plastic kettles can be a source of daily human exposure to nanoplastics and microplastics and that new plastic kettles release notable concentrations of these particles into water during boiling.’’
The research found hard tap water significantly reduced the amount of nanoplastic particles released, likely due to minerals forming a protective coating inside the kettle. Discarding the water from the first few boils of a new plastic kettle could also reduce particle release and ingestion, and this was already recommended by some kettle manufacturers.
See ECHA's latest microplastics reporting obligations.
“Simple rinsing before first use is common, but it does not achieve the same level of removal as repeated cycles of boiling and discarding," Dr. Okoffo said. “Many people may overlook or skip this step, highlighting the need for clearer product labelling and instructions.
“I would call on manufacturers, policymakers and regulators to inform consumers with safety guidelines or product labels warning about plastic particle release. Although particle concentrations drop with repeated use, our research shows there is a continuous, low-level exposure risk."
Dr. Okoffo said the study demonstrated the importance of further investigation into human health implications of prolonged exposure to plastic particles.
“The concentrations of these particles and the extent of human exposure remain poorly understood," he said.
“The study fills an important knowledge gap about how plastic products used in homes can contribute to daily plastic exposure and how small, practical changes in everyday routines can reduce exposure to plastics. By combining better product design, improved labelling, and public awareness, we can help limit the amount of plastic entering both our bodies and the environment."