Is it safe to use powdered infant formula stored in an open plastic tub?
The tub itself can add microplastics and phthalates. A 2025 study found contamination in most tested formulas.
What's actually in it
Many infant formula tubs are polypropylene with a multi-layer plastic lid. The powder touches the plastic walls every time you close the lid. Over weeks of use, the powder picks up microplastics, phthalates, and sometimes bisphenols from the packaging.
The first few feeds after opening a fresh can tend to have lower contamination than feeds after the can has been open for weeks.
What the research says
A 2025 study in Environ Res tested popular infant formula brands and found microplastics, BPA, and phthalates in every sample. Estimated daily intake crossed European safety thresholds for many babies.
Use formula within the time the manufacturer recommends after opening (usually 30 days). For best storage, transfer powder from a plastic tub to a glass jar with a metal lid and keep it cool. Or buy formula in metal cans with liners rated food-contact safe.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Microplastics and endocrine-disrupting byproducts in popular infant formula brands. | Environ Res | 2025 |
What to use instead
Browse our vetted, non-toxic alternatives. Every product is third-party certified.
Shop Non-Toxic Baby