Is it safe to store breast milk in glass vs plastic bottles?

What's actually in it

Plastic bottles are not just containers. They are sources of chemical exposure. When you use plastic to store or heat breast milk, you risk exposing your baby to microplastics and chemical additives. These materials can break down and move into the milk, which your baby then consumes.

Common plastics used for storage often contain phthalates (chemicals that make plastic soft) and other additives that can end up in breast milk. Beyond the plastic itself, research indicates that packaged milk products can contain microplastics that disrupt how the body functions.

What the research says

The science is clear: plastic containers can negatively impact the quality of milk. A 2026 study in FASEB J found that polystyrene microplastics can disrupt the transmission of the breast milk microbiome. This is critical because this microbiome is essential for early-life gut health and immune system development in infants.

Other research highlights the burden of chemical exposure. A 2026 study in Ecotoxicol Environ Saf focused on the presence of phthalates and DINCH metabolites in breast milk, confirming that these chemicals are present in the maternal body and can reach infants. a 2026 study in Food Chem Toxicol confirmed that packaged milk products are a source of microplastic exposure, noting that these particles pose a risk to human health through dietary intake.

When you choose glass, you avoid these risks. Glass is stable, does not shed particles, and does not leach chemicals into your milk, providing a safer way to store and feed your baby.