Are Japanese cast iron teapots (tetsubin) safe for brewing tea daily?
Enameled tetsubin interiors are safe. Unlined cast iron tetsubin may impart iron to tea, which is generally harmless.
What's actually in it
The answer to this question depends on conditions: what material, what temperature, how often, and what alternatives you have available.
Research shows that under some conditions this is low risk, and under others, chemical transfer is measurable. Understanding when matters.
What the research says
Enameled tetsubin interiors are safe. Unlined cast iron tetsubin may impart iron to tea, which is generally harmless.
The research base on household chemical exposure from everyday products continues to grow. Studies consistently show that material selection is the most controllable variable for reducing exposure at home.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| What Drives Microplastic Exposure in Human Blood and Feces? Machine Learning Reveals Potential Key Influencing Factors. | Environ Sci Technol | 2026 |
What to use instead
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