Bisphenol A damages the way hormones regulate (control) the human body (endocrine disruptor). BPA can pretend to be the body's own hormones. BPA may cause health problems. Very young children are most sensitive to BPA. Some studies have shown that there is a link (connection) between BPA exposure before birth (prenatal) and later problems of the nervous system. Health organizations have decided how much BPA (in a substance) is safe for people. But new studies have caused other scientists and health organizations to disagree with these decisions. A 2011 study that investigated the number of chemicals to which pregnant women in the U.S. are exposed found BPA in 96% of women.