Bisphenol-A, also known as BPA, is an estrogen-like chemical used in many plastics. The chemical also lines the inside of metal food cans. Studies have linked BPA exposure to obesity, heart disease and cancer.

However, the U.S. FDA has thus far refused to take any precautionary steps to reduce public exposure to BPA. The agency declined to act on BPA even when Canada took steps to reduce child exposure. Manufacturers of BPA say that there is no proof that BPA causes disease.

But BPA contaminates the food in cans, according to scientists with the nonprofit Environmental Working Group. The organization found that infant formula, ravioli and chicken soup contained the most BPA -- one to three servings from any of the three had enough BPA to do harm. The National Toxicology Program under the National Institutes of Health also concluded that BPA posed some danger. In a report, it cited "some concern for effects on the brain, behavior and prostate gland in fetuses, infants and children at current human exposures to Bisphenol-A."