More BPA from boiling water in a bottle
New research shows that hot liquids increase leaching of bisphenol A from polycarbonate plastics.
Hot water in a polycarbonate plastic container can trigger the release of high levels of the endocrine disrupter bisphenol A (BPA), according to new research published January 30 in Toxicology Letters (2008, DOI: 10.1016/j.toxlet.2007.11.001).
Scott Belcher of the University of Cincinnati and colleagues evaluated BPA migration in both new and used heavy-duty polycarbonate bottles. They report that boiling water can increase the movement of BPA out of such plastics as much as 55 times compared with water at room temperature. The migration rates did not correlate with the age of the bottles.
The researchers confirmed the extra estrogenicity, which has neurotoxic effects, with in vitro assays of developing brain neurons.
Although previous research has shown that polycarbonate bottles release BPA when heated in a microwave or a hot dishwasher, the new study is the first to mimic real-life behavior, says endocrine-disrupter expert Frederick vom Saal of the University of Missouri.
"A lot of people take coffee and hot liquids and put them in these bottles," says vom Saal. The new work points to "a substantial exposure" to BPA, he adds, even if an unheated bottle is filled with hot water and allowed to cool. Even more BPA can leach into acidic liquids like juice, vom Saal notes, making these estimates "highly conservative."
The authors write that this contact adds to people's total BPA exposure, which can also come from other polycarbonate plastics, such as baby bottles or linings in food cans. Because baby bottles are regularly heated or filled with warm fluids, infants could be getting extremely high exposures compared with adults, says vom Saal.
