The household kettle is a hardworking little appliance. Throughout any given day, it boils water for countless cups of tea, prepares instant noodles and soups, speeds up stovetop cooking and warms baby bottles, all without missing a beat. But while its work ethic is to be commended, your kettle could be harbouring an unpleasant secret.

A recent study out of the University of Queensland found that boiling water in plastic kettles leaches nano- and microplastic particles into the liquid. 

Researchers tested Australian-sourced polypropylene plastic kettles, boiling them up to 150 times and measuring the release of nanoplastics and microplastics into water in the kettles during boiling. 

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How many microplastics is my kettle releasing?

They found that the first boil in a new kettle released almost 12 million nanoparticles per millilitre – that equates to almost 3 billion particles in an average 250ml cup of tea.

Many kettle manufacturers will recommend you rinse your new kettle, and then discard the first few boils before use, however, even after 150 boils, the researchers found there were still 820,000 nanoparticles detected in the boiled water per millilitre, or 205 million per 250ml.

Credit: iStock

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What’s the difference between microplastics and nanoplastics?

Microplastics are plastic particles that are smaller than 5 millimetres and down to 1 micrometre (that’s one-millionth of a metre). Nanoplastics are particles that are under 1 micrometre. Researchers are still working to understand what kind of long-term effects these teeny particles might have on human health. 

“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,’’ says researcher Dr Elvis Okoffo. 

“Although particle concentrations drop with repeated use, our research shows there is a continuous, low-level exposure risk.’’

The study did find that hard tap water significantly reduced the amount of nanoplastic particles released – this is likely due to minerals from the water forming a protective coating inside the kettle.

But if these findings have freaked you out as much as it has the tea-loving team at delicious., it might be time to invest in a plastic-free kettle. 

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