Microplastics in Baby Bottles: Infant Health Risks Explained

This article is for general information and is not medical advice. If your baby was born early, has a weakened immune system, or you have questions about preparing formula safely, talk to your pediatrician.

By Justin Gurinskas, Co-Founder, Quark Baby. Checked against the published study and current statements from the FDA, the World Health Organization, the CDC and the American Academy of Pediatrics.

You read a headline at 2am, mid-feed, that said baby bottles release millions of plastic particles. Now you are looking at the bottle in your hand and wondering whether you have been doing something wrong every day since your baby was born.

You haven't. Here is what the research actually shows. Plastic baby bottles can release microplastics, and the study behind those headlines found that heat is what drives it. What nobody has shown yet is that the amounts involved harm babies: the FDA says current evidence "does not demonstrate" a health risk from the levels found in food, and a 2025 review of children's exposure says human data are still scarce. So this is a case for a few cheap habits, not for throwing out your bottles. Below: what the study measured, what the health-risk research does and does not show, how bottle materials compare, and the changes the study's own authors suggested.

Microplastics in baby bottles: what the 2020 Nature Food paper found

Almost every headline traces back to one paper: Li and colleagues, published in Nature Food in 2020 by a team at Trinity College Dublin. They tested polypropylene (PP) infant feeding bottles, the most common plastic for bottles worldwide, using the formula preparation steps parents are normally told to follow.

From the summary of Li et al. (2020):

• PP bottles released microplastics "with values as high as 16,200,000 particles per litre." That is the top of the range, under the hottest conditions they tested, not a typical feed.
• Sterilizing the bottle and exposing it to high-temperature water "significantly increase[d] microplastic release."
• Estimated exposure for babies up to 12 months ranged from 14,600 to 4,550,000 particles per day, depending on the region, because bottle and formula habits differ so much between countries.
• Li et al. concluded there is "an urgent need to assess whether exposure to microplastics at these levels poses a risk to infant health." In other words, the study measured release. It did not measure harm.

Two things Li et al. (2020) did not test are worth knowing. It looked at polypropylene bottles only, so it says nothing direct about glass, stainless steel, Tritan, PPSU or polyamide bottles. And it tested bottle bodies, "not including accessories," so nipples, rings and lids were outside its scope.

Do microplastics in baby bottles harm infant health? What the evidence says

This is the question behind most searches, and the evidence is clearer about what is unknown than about what is known.

• The FDA (content current as of July 24, 2024): "Current scientific evidence does not demonstrate that levels of microplastics or nanoplastics detected in foods pose a risk to human health." It notes microplastics have been reported in salt, seafood, sugar, beer, bottled water, honey, milk and tea, and says it will act if the evidence changes.
• The World Health Organization reviewed studies published up to December 2021 on exposure from food, water and air, and its 2022 report identified research needs "to address current uncertainties" rather than a confirmed health risk.
• A 2025 scoping review in Toxicology Reports (Nadarasan et al.) pulled together the research on children's exposure. It found that across five papers on feeding and plastic bottles, the microplastics released "ranged from 0.625 to 393 particles/ml," and it states plainly that "there is a scarcity in the available data from human studies, particularly on the exposure of MPs in early childhood." Most of the harm signals it discusses come from animal and cell studies.

Our reading: the release is real and measurable, and the harm is unproven. Reducing an exposure that is easy to avoid is still reasonable, and both Li et al. (2020) and Nadarasan et al. (2025) call for more research on infants specifically. It is the same logic as washing produce. You do not need proof of harm to take an easy step that cuts an avoidable exposure.

If you are weighing the wider question of what else to look for in a bottle, our guide to what parents worry about in baby bottles covers BPA, phthalates and certifications.

Baby bottle materials compared

Material is the one choice you make once. Here is what each common option is, what it is good at, and how much of the microplastics evidence actually covers it. Glass gets our pick for the bottle body if microplastics are your main concern, because it is not a plastic at all. Its weight and breakage risk are the honest trade-offs.

A few things the table cannot tell you. "No" in the last column means untested in Li et al. (2020), not proven to release nothing. A glass or steel bottle almost always still has a silicone nipple and a plastic ring or lid, so even a glass bottle is not a plastic-free feed. And a recycling code on the base (especially #7, a catch-all for "other" plastics) tells you very little about which material you have; the manufacturer's stated material is more useful. Our side-by-side of glass, silicone and plastic bottles goes further into weight, cleaning and durability, and polyamide vs PPSU compares the two lighter plastics directly.

Where our own bottles sit

Our BuubiBottle Mini and Max bodies are Grilamid TR-90 polyamide, as listed on their product pages, with a silicone RealFeel nipple. We chose the material for clarity, light weight and drop resistance. We have not seen published research (as of 2026) that measures microplastic release from polyamide baby bottles, so we are not going to tell you it sheds less than polypropylene. What we can say is that the habits below apply to every plastic bottle, including ours. More on the material itself is in what Grilamid TR-90 is.

How to reduce microplastics when bottle-feeding

The Trinity College Dublin authors (Li et al., 2020) gave their own advice when the paper was published. Every step works on the same lever: keep very hot water and plastic apart.

1. Rinse after sterilizing. The authors suggested rinsing sterilized bottles with cool sterile water to wash away particles that may have been released during sterilizing.
2. Prepare formula in a non-plastic container (glass or stainless steel), then pour it into the cooled bottle. If your pediatrician or your formula's instructions call for mixing powder with hot water, for example for a newborn or a baby with a weakened immune system, follow that safety guidance first and ask how to combine it with this step.
3. Never microwave the bottle or the feed. This one is also a burn rule: the American Academy of Pediatrics says to "never microwave formula" because microwaving "can affect ingredients in formula and cause hot spots in the liquid that can burn your baby's mouth." Warm a bottle in a container of warm water or with a bottle warmer instead.
4. Warm milk in a separate vessel when you can. If you reheat, the authors advised avoiding rewarming prepared formula in plastic containers. A warmer with a stainless steel vessel, such as our BuubiBottle Portable Milk Warmer PRO, lets you warm milk or water away from the bottle and then pour.
5. Sterilize when it is needed, not by habit. The CDC says to sanitize feeding items daily if your baby is under 2 months old, was born prematurely, or has a weakened immune system, and that daily sanitizing "may not be necessary for older, healthy babies, if those items are cleaned carefully after each use." Fewer high-heat cycles means fewer chances for release. Our guide on when you actually need to sterilize bottles walks through it.
6. Wash with a soft brush and replace worn parts. Retire a bottle that looks cloudy, cracked or deeply scratched, and follow the manufacturer's replacement guidance for nipples. Wide-neck bottles are easier to reach into with a soft brush; see wide-neck bottles and cleaning.

For the warming part specifically, our guides on bottle warmer vs warm water and the right milk temperature cover how warm is warm enough. If you are travelling, warming milk away from home covers options without a kitchen.

Are plastic baby bottles still safe to use?

Based on what the FDA and WHO say today, yes, with the habits above. No health authority has told parents to stop using plastic bottles. The strongest case for plastic is practical: it is light enough for a baby to hold, it survives being dropped on a tile floor, and it is easy to carry. The strongest case for glass is that it takes plastic out of the bottle body entirely. Either is a reasonable choice. What matters more than the material is not filling any plastic bottle with very hot water, and not microwaving it.

If you are choosing a bottle from scratch, our guide to choosing a baby bottle and bottle comparison by venting, parts and materials cover the rest of the decision.

Frequently asked questions

Sources

• Li D. et al., Nature Food (2020): Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation
• Nadarasan et al., Toxicology Reports (2025): Microplastics and child health: a scoping review of prenatal and early-life exposure routes and potential health risks
• U.S. Food and Drug Administration: Microplastics and Nanoplastics in Foods (content current as of July 24, 2024)
• World Health Organization (2022): Dietary and inhalation exposure to nano- and microplastic particles and potential implications for human health
• Centers for Disease Control and Prevention: How to Clean, Sanitize, and Store Infant Feeding Items (updated March 19, 2025)
• American Academy of Pediatrics (HealthyChildren.org): How do I mix and serve infant formula for my baby? (last updated March 23, 2018)
• TODAY (November 2020), reporting the study authors' advice to parents: Baby bottles can shed millions of microplastic particles

Medically reviewed by Dr. Yang. Last reviewed October 2, 2026.

Disclaimer: This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your pediatrician or other qualified health provider with any questions regarding your baby's health or feeding.