ROCKVILLE, Md., Nov. 26 -- A trace amount of melamine, the toxic chemical that has sickened tens of thousands of infants in China, was found in a U.S.-manufactured infant formula, the FDA confirmed.
A spokesperson for the agency would not identify which brand was affected, and said that "extremely low" levels of the chemical were found in only one of 77 samples tested.
The agency is awaiting results on another 10 samples.
Stephanie Kwisnek, with the FDA's Center for Food Safety & Applied Nutrition stressed that the agency believes U.S.-produced infant formula is safe. There are no plans for recalls, she said.
"There's no concern for public health. FDA's advice to parents is to continue to use U.S.-produced infant formula. It is safe, effective, and wholesome. There's no health risk," according to Kwisnek.
The contamination is believed to be the result of the manufacturing process, she said. Melamine is approved for use in can liners.
Testing in the U.S. began in September following the discovery of melamine-contaminated infant formula in China, which has sickened more than 50,000 Chinese infants and killed four.
In the contaminated U.S.-produced sample, the FDA detected levels of 137 parts per billion and 140 parts per billion.
On Oct. 3, the agency announced that it could not establish any safe level for melamine in infant formula. (See: FDA Says No Safe Level of Melamine in Baby Formula)
But, Kwisnek said, the agency has continued testing since then and is in the process of updating its risk assessment for melamine. There is no timetable for its release.
Even though there is no accepted safe level of melamine for infant formula, she said, the concentrations detected are so low that the agency would not expect them to be dangerous.
There have been no illnesses reported in the U.S. in connection with melamine-tainted formula.
The finding of contaminated U.S.-manufactured products was first reported by the Associated Press, stemming from a Freedom of Information Act request.
The AP identified the melamine-contaminated sample as Mead Johnson's Enfamil LIPIL with Iron.
Another sample -- Nestle's Good Start Supreme Infant Formula -- was tainted with cyanuric acid, a byproduct of melamine, the news organization said.
Several products have been pulled from the market over the past two months because of suspected melamine contamination, including a fruit-flavored drink called Blue Cat, YILI Brand Sour Milk Drink, YILI Brand Pure Milk Drink, and several Mr. Brown coffee and tea products. (See: Chinese Melamine Contamination Triggers U.S. Recall of Instant Coffee and Tea Products, Fruit-Flavored Drinks Tainted by Chinese Melamine, and FDA Finds Melamine in Asian Milk Drinks)