Bisphenol A, in commercial use since the 1950s, is found in a wide variety of everyday items, including plastic beverage containers, eyeglasses and compact discs. It is ubiquitous: One recent federal study estimated that the chemical is found in the urine of 93 percent of the U.S. population. Commonly called BPA, the chemical mimics the hormone estrogen and may disrupt the body's endocrine system. Public health advocates say it poses a particular danger to fetuses, infants and children because BPA can interfere with cell function at a point when their bodies are still developing.