Do Kettles Release Microplastics?
Water Touches Only Steel.

Yes. Plastic kettles shed micro- and nanoplastic particles into water during boiling, and the release is highest when the kettle is new. University of Queensland research (2025) found a new kettle's first boil released roughly 12 million nanoparticles per milliliter — and particles were still detectable even after 150 uses. Heat accelerates this shedding, which is why a boiling kettle is a meaningful exposure source.

Source: Shi, Okoffo et al., npj Emerging Contaminants (2025)

Not necessarily. Many kettles marketed as "stainless steel" still contain plastic in the parts that touch water — water-level gauges, lids, seals, filters, and interior linings. The label describes the body, not the full water path. That's why we built every water-contacting surface of the Luna Kettle from 304 stainless steel, with no plastic contact point.

No. "BPA-free" only means one specific chemical (bisphenol A) is absent — the plastic itself is still there and can still release micro- and nanoplastic particles when heated. Avoiding microplastic exposure requires removing plastic from the water path entirely, not replacing one plastic with another.

It depends on the container. Boiling in a plastic kettle adds particles shed by the plastic, but boiling itself can reduce microplastics already present in tap water. A 2024 study found that boiling and filtering calcium-rich tap water removed up to about 90% of nano- and microplastics. Boiling in a plastic-free kettle gives you that benefit without turning the kettle into a new source of plastic.

Source: Yu et al., Environmental Science & Technology Letters (2024)

The long-term health effects are still being studied, but microplastics have now been detected inside the human body — in blood, lung tissue, and brain tissue. Laboratory studies suggest particles of this size can trigger inflammation. Because the risks aren't yet fully understood, many people choose to limit avoidable exposure where they reasonably can.

Source: Leslie et al. (2022); Jenner et al. (2022); Nihart et al. (2025)

Focus on the sources you can control. Three evidence-based steps: boil and filter hard tap water (removes up to ~90% of particles), reduce single-use plastic bottles (93% of bottled water samples contained microplastics), and remove plastic from anything heated with your water — starting with your kettle.

Source: Yu et al. (2024); Mason et al. (2018)

Yes. Researchers describe the first uses of a plastic kettle as a "burst release phase," when heat and friction trigger the highest particle release. University of Queensland measurements (2025) showed the highest levels in the first few boils, declining over time but never reaching zero. A plastic-free kettle avoids this entirely.

Source: Shi, Okoffo et al., npj Emerging Contaminants (2025)

The water path is every surface your water touches from filling to pouring: the interior wall, the heating base, the lid underside, the spout, the strainer, the fill marks and any seal or gasket in between. Many kettles hide plastic in these components even when the outer body is metal. We engineered the entire Luna water path from 304 stainless steel, with no plastic contact point, because purity only counts where the water actually goes.

The Saki Luna Kettle was tested by Light Labs, an independent ISO/IEC 17025 accredited laboratory in Ann Arbor, Michigan, for bisphenols (BPA, BPS, BPF), phthalates (16 compounds), PFAS (30 compounds) and heavy metals (arsenic, cadmium, lead, mercury). Every analyte returned Not Detected. The full Certificate of Analysis is published on this page and on the Luna product page, so you can read the results yourself rather than take our word for it.