Are plastic baby bottles releasing microplastics when heated?

What's actually in it

Plastic baby bottles are often made from materials like polyethylene terephthalate. These plastics are not stable when exposed to heat. They can break down and shed tiny particles known as microplastics into the liquid inside the bottle.

Once these particles are in the bottle, they are easily swallowed by your baby. These microplastics are not just inert pieces of debris. They are foreign materials that your body has to process, and they have been found in human tissues, including the placenta, according to a 2026 study in Ecotoxicol Environ Saf.

What the research says

The science is clear that consuming microplastics has real effects on health. A 2026 study in Drug Chem Toxicol found that even a single oral exposure to polyethylene terephthalate microplastics causes metabolic and gastrointestinal disruption.

These findings are part of a growing body of peer-reviewed research showing how plastic particles move through our environment and our bodies. A 2026 study in Environ Health Prev Med highlights the relationship between microplastics in the diet and changes in inflammatory markers. Because microplastics are now found in indoor environments, as noted in a 2026 study in Chemosphere, reducing your baby's exposure to plastic bottles is a necessary step to limit their total intake.