Best non-toxic water bottles

Stated water-contact materials, an uncoated interior, and — the criterion that actually separates these products — a cap whose material is published. We also preferred bottles with wide mouths, because a bottle you cannot get a brush into is a bottle that grows things.

We have not tested insulation performance or drop survival. Those are measurable claims the manufacturers make, and we have reported rather than verified them.

Not meaningfully for its intended use. The leaching research this site cites repeatedly — Kamerud et al. (2013), measuring nickel and chromium migrating into tomato sauce — involved hours of simmering an acidic food. Plain water at ambient or cold temperature is nothing like that condition.

Where it becomes a reasonable question is acidic contents left all day: lemon water, a vinegar drink, an acidic sports mix. For those, glass is the better container.

1. Wash it daily, especially if anything other than water has been in it. A bottle brush is the only tool that reaches the bottom.
2. Take the cap apart. Gaskets and valves are where biofilm sits, and a cap washed assembled is a cap not washed.
3. Do not put hot liquids in a single-wall bottle, which becomes too hot to hold; and avoid leaving acidic drinks sitting for hours.
4. Retire a dented insulated bottle that has stopped holding temperature — the vacuum has failed, which is the whole mechanism.
5. Replace worn silicone gaskets rather than tolerating a leaking cap.

Plastic bottles generally, since this page exists to replace them. Insulated bottles with a coated or painted interior, where a coating is the one thing an uncoated stainless bottle is meant to avoid. Aluminum bottles with an interior liner, since the liner is the food-contact surface and is rarely specified. And collapsible silicone bottles where the cure type is not published.