FDA , cyanuric acid not of concern in levels below 1,000 parts per 1,000 . Official says Melamine has tested billion samples of U.S.-made baby formula . The combination caused crystals to form in the animals ' kidneys . Some samples tested positive but at safe levels , official says . Levels are far below those associated with Chinese contamination .
FDA , cyanuric acid not of concern in levels below 1,000 parts per 1,000 . Official says Melamine has tested billion samples of U.S.-made baby formula . Some samples tested positive but at safe levels , official says . Levels are far below those associated with Chinese contamination .