Study: Plastic Baby Bottles Shed Microplastics When Heated. Should You Be Worried? - NPR

A new study shows that plastic baby bottles, when heated or shaken, release microplastics into the liquid.

A new study shows that plastic baby bottles, when heated or shaken, release microplastics into the liquid.

And they're released in huge quantities from plastic baby bottles when they're used to prepare formula according to standard guidelines, a new study in the journal Nature Food finds.

"The last thing we want to do is unduly alarm parents," said John Boland, a professor of chemistry and materials science researcher at Trinity College Dublin in Ireland and one of the authors of the Nature Food study.

Boland said he and his co-authors decided to look at microplastics released by plastic baby bottles in part because there are a small number of products on the market.

The researchers selected 10 types of plastic baby bottles, representative of nearly 70% of the global market, and measured the levels of microplastics released when they were used to prepare infant formula according to guidelines set by WHO.

What they found was that the release of microplastics was highly temperature sensitive, Boland said.

When the researchers filled the plastic baby bottles with room temperature water and shook them for about 60 seconds, to simulate normal formula preparations, "you get hundreds of thousands of microplastics," he said.

Meanwhile, in China, where glass baby bottles are more popular, the average infant's consumption of microplastics is estimated to be in the "tens of thousands" of particles, Boland said.

While the levels of microplastics detected by the new Nature Food study are quite high, they are in line with levels reported by a 2019 study that found that plastic tea bags – the kind often found in pyramid-shaped bags – can release billions of plastic microparticles when steeped in hot water, noted Schwabl, who wrote a commentary in Nature Food on the findings from Boland and his colleagues.

Schwabl said that points to a need for more research into microplastics released from plastic food storage containers, especially when they are subjected to higher temperatures.