The Food and Drug Administration said it also found trace levels of the industrial chemical in other products such as nutritional and medical supplements produced by U.S. infant formula manufacturers, The Wall Street Journal reported Wednesday.

The levels of melamine "are extremely low," said Dr. Stephen Sundlof, director of the agency's Center for Food Safety and Applied Nutrition. "It didn't cause any concern at all, not from a health standpoint."

The agency tested products from the five FDA-approved makers of milk-based infant formulas -- Abbott Laboratories (NYSE:ABT), Bristol-Myers Squibb Co. (NYSE:MY), Nestle SA's Nestle USA unit, PBM Products LLC and Solus Products LLC. Sundlof told the Journal the traces stemmed from the products coming in contact with melamine during processing.

The FDA approved melamine as a "food contact substance" about 40 years ago, the Journal said.

Melamine traces in the U.S. products were detected by a testing program the FDA began after Chinese-made infant formula tainted with much higher levels of melamine sickened tens of thousands of babies in China and led to at least four deaths.