Breast milk being the best milk may have more wisdom behind it than just a happily coincidental rhyme nowadays.

Distressingly, the simple couplet may be more pertinent not for what it provides nutritionally, but for what it leaves out of infant diets – namely perchlorate, a chemical used in rocket fuel, which has been found in baby formula according to a study by the Center for Disease Control.

The study doesn’t name names of the 15 brands it tested, but researchers were able to say that all 15 brands contained perchlorate, and that contamination levels were highest in the most popular brands.

Particularly troubling is that most of the formulas are being combined with tap water, and almost all tap water contains perchlorate. Researchers hypothesized that up to 54% of children drinking formula could be getting a daily dose of rocket fuel ingredient above the safe limit suggested by the EPA. But with the EPA still dragging it’s feet on setting regulations for perchlorate levels in drinking water, at this point, all we can do is hope that the chemical renders children swifter and more energetic, rather than causing lasting harm.

For more info, check out the full study here.