The Environmental Working Group (EWG) performed laboratory tests on cash register receipts from major U.S. businesses and found bisphenol A (BPA) present on 40% of them, some at levels higher than those found in canned foods, baby bottles and infant formula. BPA is an estrogen-like, plastic-hardening chemical added to many everyday items and that has been linked to breast cancer, heart disease, diabetes and other illnesses. It reacts with dye to form the black or colored print on heat-sensitive paper receipts that millions of people are handed every day while doing business at retail stores. The U.S. Food and Drug Administration had previously declared BPA safe, but announced in January, 2010 that in light of new studies it now has "concerns" about the chemical's potential effects on brain development of fetuses, infants and children. It stopped short of saying BPA is unsafe. The receipts EWG tested came from businesses in seven states and the District of Columbia, including Safeway, CVS, Whole Foods, Walmart, Chevron, McDonald's, the U.S. Postal Service and cafeterias in the U.S. Senate and House of Representatives. The American Chemistry Council, which represents the chemical industry, maintains the concerns about exposure to BPA are overblown.