Healthnotes Newswire (March 20, 2008)—It’s hard to picture how people stored and carried food and beverages before plastic. Now after many decades of use, researchers have discovered that some plastics are better than others, and some should be avoided by health-conscious consumers. Of particular concern is a plastic component called bisphenol A—or BPA—which is found in the polycarbonate plastics used in many reusable water bottles, baby bottles, sippy cups, and food storage containers, and in the liners of canned foods and drinks.

The study, published in Toxicology Letters, looked at how much BPA gets into water stored in new and used polycarbonate bottles. For up to seven days, the bottles were exposed to conditions of normal use, including sterilization in boiling water, after which the water was tested. BPA leached into the water in both new and used polycarbonate bottles at the same rates, and BPA concentrations increased over time. Exposure to boiling temperatures caused more BPA to leach into the water—up to 55 times that seen at room temperature.

Even in very small amounts, BPA acts like estrogen in the body, potentially triggering hormonal changes. Although no studies regarding BPA toxicity in humans have been done, studies have shown that animals exposed to BPA develop early puberty, reproductive system defects, and breast and prostate cancers. Children’s developing systems are more sensitive to the effects of BPA and other chemicals.

The authors commented, “Our results confirm and extend previous studies that demonstrated migration of BPA from polycarbonate plastics. The amounts of BPA found to migrate from polycarbonate drinking bottles should be considered as a contributing source to the total endocrine disrupting chemical burden to which some individuals are exposed.”

How to decrease BPA exposure

The Environmental Working Group offers the following suggestions for limiting BPA exposure.

• If using infant formula, choose powdered over liquid. (Formula manufacturers use BPA in the lining of their cans.)

• Look for BPA-free plastics, such as those with the recycling numbers 1, 2, and 4. Soft or cloudy appearing plastics are also usually free of BPA. Note that most (though not all) #7 plastics contain BPA.

• Get your food fresh, frozen, or boxed (such as aseptic soup and drink boxes). While a few companies, such as Eden Organic Foods do not use BPA in their can liners, most cans contain BPA that leaches from plastic resins in their liners.

• Choose reusable stainless steel water bottles like Klean Kanteen, or those with a non-leaching water-based liner, such as Sigg bottles. Avoid using old, scratched plastic bottles for storing drinking water or food.

• Reheat foods in glass or ceramic containers. Do not heat plastics in the microwave.

• For BPA-free baby bottles, try glass or Born Free bottles.

(Toxicol Lett 2008;176:149–56)