Small “trace amounts” of industrial and potentially toxic chemical melamine were detected in U.S.-produced infant formula. However experts say they pose little risk to children, if any.

Associated Press investigative reporters obtained FDA documents that showed the organization was testing U.S. baby formula for melamine.

According to the press report, one brand of formula contained tiny amounts of the chemical, and another contained similarly small traces of cyanuric acid, a related substance. A third manufacturer told press that its internal tests detected small amounts of melamine in its own formula.

The issue of melamine is a sensitive one since in China the chemical being added deliberately to infant formula in order to make it seem to have higher protein content led to 52,000 children developing kidney stones. The aftermath yielded 13,000 hospitalizations and at least two babies dead.

The FDA did not find any Chinese infant formula in the U.S., and issued a warning to manufacturers and traders not to import milk products from China unless they test them for melamine contamination.

American infant formula does not contain Chinese milk products. The chemical’s presence in U.S. formula products was apparently due to routine contact with substances which contained melamine during the manufacturing process. Intentional inclusion of melamine in the product is not considered likely.

Melamine, or cyanuramide, is a synthetic chemical formed from hard resins and formaldehyde. It has, among other uses, a role as industrial coating, and may therefore have thus found its way into the formula during manufacture.

It can cause problems from discomfort to kidney stones, or even kidney failure and death depending on the dosage. Experts say that the amounts present are so small that they shouldn’t pose a health problem, but do warn to exercise caution when choosing formulas nevertheless.

The brands of formula which include traces of melamine are Mead Johnson's Infant Formula Powder, Enfamil LIPIL with Iron; and cyanuric acid was found in Nestle’s Good Start Supreme Infant Formula with Iron. Both were in concentrations some two thousand times smaller than in contaminated Chinese formula.