Can hot water in plastic containers raise microplastic exposure?
A 2025 Food Chemistry study found that plastic containers released microplastics and nanoplastics after hot water treatment, and those particles amplified disinfection byproduct toxicity in human cells.
Short answer
Heat is the key concern. A 2025 Food Chemistry study found that feeding bottles, food containers, and paper cups released about 10,000 microplastics and 10,000,000 nanoplastics after hot water treatment.
Those released particles were not toxic by themselves in 6 human cell types. But they did amplify the toxic response of disinfection byproducts, which can be present in drinking water.
This does not mean every plastic bottle makes tap water dangerous. It does support avoiding hot water in plastic containers.
What to do
Use glass storage for water when you can. Do not pour hot water into plastic bottles, plastic food containers, or coated paper cups. Let water cool before it touches plastic.
The research at a glance
What to use instead
Use glass storage for water and leftovers when you can. Avoid putting hot water in plastic containers or coated paper cups.
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