Perchlorate, a chemical that is the main ingredient in solid rocket fuel, has been detected in 15 brands of baby formula, according to testing by the Centers for Disease Control and Prevention:

While the levels of the chemical, perchlorate, have been deemed safe by the Environmental Protection Agency, some worry public health is at risk.

Scientists at the Centers for Disease Control and Prevention tested the formula for the presence of perchlorate, a chemical used as the main ingredient in solid rocket fuel. It’s a worry because perchlorate can interfere with the production of thyroid hormones by inhibiting the absorption of iodine.

The CDC study found cow’s milk-based formula contained more perchlorate than that made with soy or other ingredients.

The two brands with the highest levels — more than double that of the other milk-based products — command 87 percent of the market share for infant formula.

The report does not specify the brand names of any formula tested.

Perchlorate from rocket fuel has been detected in the water in 35 states. It is believed that it is absorbed in grass, which is then eaten by cows.