Do plastic baby bottles shed microplastics? What to know

Yes: in a 2020 lab study, polypropylene bottles shed up to 16.2M particles per litre with 70°C water, more when hotter. The health effect hasn’t been assessed.

Yes. In a 2020 lab study, polypropylene bottles shed microplastics into hot water, and sterilising and hotter water increased it. Whether that harms babies hasn’t been assessed yet.

3 min read · Written by Ken · Checked Oct 2026 · 4 sources

What the 2020 study measured

16.2Mparticles per litre at most, sterilised then filled with 70°C water

0.6M–55Mparticles per litre, as the water went from 25°C to 95°C

48regions in the babies’ exposure estimate

The study’s lead authors, on health“We don’t yet know the risks to human health of these tiny plastic particles.” Source 2

Lab tests of polypropylene bottles, not measurements of real feeds. Study figures as reported Source 1 Source 2

Do plastic baby bottles shed microplastics?

Yes, plastic baby bottles shed microplastics. In a 2020 study, polypropylene feeding bottles released microplastics “with values as high as 16,200,000 particles per litre”, and sterilisation and high-temperature water “significantly increase” the release. Source 1

That 16.2 million came from the team’s standard test: bottles sterilised, then filled with 70°C water. With 25°C water they found about 600,000 particles per litre, and with 95°C water as many as 55 million. Source 2 These are lab results, not counts from real feeds. The team also estimated babies’ daily exposure in 48 regions, from about 14,600 to 4.55 million particles a day depending on the region. Source 1

Is it harmful to babies?

Nobody knows yet whether these particles harm babies. The study authors say research is needed into “whether exposure to microplastics at these levels poses a risk to infant health”. Source 1 FDA says current evidence “does not demonstrate” that the microplastic levels found in foods pose a risk to human health, and that more research is needed. Source 3

So this is a reason to cut exposure where it’s easy, not a reason to panic. Trinity College Dublin’s Professor John Boland, whose team ran the study, said: “The last thing we want is to unduly alarm parents.” Source 2

Should I use cooler water to make formula?

Not to protect the bottle. Powdered formula isn’t sterile, and CDC says “very hot water (around 158°F/70°C) is needed to kill these germs”, such as Cronobacter. CDC asks for this extra step for babies younger than 2 months, born prematurely or with a weakened immune system. Source 4 Otherwise, follow the instructions on your formula’s container, and ask your baby’s doctor if you’re unsure.

The researchers suggest moving the hot step out of the plastic instead: boil water in a non-plastic kettle, mix the formula in a non-plastic container with water of at least 70°C, let it cool to room temperature, then pour it into the bottle. They also suggest rinsing a sterilised bottle at least 3 times with room-temperature sterilised water, and not reheating formula in plastic containers or in a microwave. Source 2 Boland said that with these steps “it is possible to mitigate the risk of ingesting microplastics”. Source 2

Are glass baby bottles plastic-free?

Not entirely. The bottle is glass, which isn’t plastic, so it can’t shed microplastics, and it handles boiling. The screw ring is plastic and sits outside the milk. Our BIBS pick has a natural rubber nipple, so skip it if anyone at home has a latex allergy; the Evenflo picks have silicone nipples.

The BIBS nipple is natural rubber: skip BIBS if anyone in the house has a latex allergy, and choose a glass bottle with a silicone nipple instead. The screw ring is plastic and sits outside the milk. Worried about drops? A cotton or knit bottle sleeve helps.

Sources (4)