The reports of the finding of the Food and Drug Administration - relating to trace amounts of melamine present in US-made baby formula - have caused alarm among parents, even as the agency claimed that the low level posed no risk.

Though FDA spokespersons did not disclose the maker of the formula that had trace melamine amounts, media outlets reported that melamine or cyanuric acid had been found in one Mead Johnson product and one Nestle product.

As such, several makers of infant formula sold in the United States defended their products on Wednesday, saying tests had not found the kidney-damaging chemical melamine in their products. Refusing to comment on the FDA's findings, they said their own tests did not detect the chemical.

Pete Paradossi, spokesman for the Bristol-Myers Squibb unit, which markets several types of Enfamil-branded formula, said: "The FDA has confirmed with Mead Johnson that melamine was not found in any of our products they tested. We have received thousands of calls from moms asking for clarification and information."

Even Hain Celestial Group Inc said its tests found neither melamine nor its related by-product, cyanuric acid, in its Earth's Best Organic formula.

Meanwhile, the other US-approved makers of milk-based baby formula - including Abbott Nutrition, Nestle USA, and Solus Products - did not return e-mails and phone calls seeking comment.

Various consumer groups have urged the FDA and the companies to make their formula findings public. Research Center for Women & Families President, Diana Zuckerman, said: "FDA needs to do much more to protect our families, and they should start by being honest with the American public."