While study after study raise questions about the safety of bisphenol A (BPA), the U.S. Food and Drug Administration maintains for now that the chemical is safe at the levels to which humans are commonly exposed.

British researchers claim in a paper published in the Journal of the American Medical Association that BPA renders people more prone to heart diseases and diabetes. Looking at urine and blood samples from 1,455 United States adults between the ages of 18 and 74, scientists found that those who had the highest level of BPA in their bodies were two times more likely to develop diabetes or cardiovascular disease.

Moreover, higher BPA concentrations were linked to abnormal concentration of three liver enzymes.

Bisphenol A is a synthetic hormone that has been shown to leach out of a certain type of plastic when heated, endangering the health of consumers. Hard polycarbonate plastic is used in baby bottles, toddler cups, water bottles and other recipients.

Bisphenol A (BPA) is an organic compound used as a building block to several important polymers and polymer additives. To some degree, it mimics estrogen. Bisphenols have also been used as antioxidants in cosmetics and foods. San Francisco banned it in products for young children effective December 2006, but the ban was not enforced and was taken back in May 2007.

In April, Canada made a decision to ban some of the products that used BPA, also declaring the chemical harmful to babies. Wal-Mart Stores Inc. and Toys "R" Us Inc., among others, have already announced they are phasing out baby bottles containing bisphenol A. Experts said that they observed developmental changes occurring in some animal studies at BPA exposure levels similar to those experienced by humans.