A government study says traces of a chemical used in rocket fuel have been found in samples of powdered baby formula.
It says the amount could exceed what's considered a safe dose for adults if mixed with water also contaminated with the ingredient.
The study by scientists at the U.S. Centers for Disease Control and Prevention looked for the chemical, perchlorate, in different brands of powdered baby formula. It was published last month, but the Environmental Working Group issued a press release Thursday drawing attention to it.
No tests have ever shown the chemical caused health problems, but scientists have said significant amounts of perchlorate can affect thyroid function. The thyroid helps set the body's metabolism. Thyroid problems can impact fetal and infant brain development.