The setting of the standard comes days after The Associated Press reported that FDA tests found traces of melamine in the infant formula of one major U.S. manufacturer and cyanuric acid, a chemical relative, in the formula of a second major maker. The contaminated samples, which both measured at levels below the new standard, were analyzed several weeks ago.
The FDA had stated in early October that it was unable to set a safety contamination level for melamine in infant formula.
Dr. Stephen Sundlof, FDA's director of food safety, said Friday the agency was confident in setting the 1 part per million level for either of the chemicals alone. although there has been no new scientific studies since October that would give regulators more safety data. He had no ready explanation for why the level wasn't set earlier.
The standard is the same as the one public health officials have set in Canada and China where in September the problem of melamine in infant formula first surfaced. But it is 20 times higher than the most stringent level in Taiwan.
Sundlof said the lack of dual contamination was key because studies so far show dangerous health effects only when both chemicals are present. He emphasized that neither of the two tainted samples had both contaminants.
The agency still will not set a safety level for melamine if cyanuric acid is also present, he said.
Both the new safety level and the amount of the chemical found in U.S.-made infant formula are far below the amounts of melamine added to infant formula in China that have been blamed for killing at least three babies and making thousands ill.
"The levels were so low ... that they do not cause a health risk to infants," Sundlof said. "Parents using infant formula should continue using U.S.-manufactured infant formula. Switching away from one of these infant formulas to alternate diets or homemade formulas could result in infants not receiving the complete nutrition required for proper growth and development."
Reacting to news of the contaminated formulas, members of Congress, a national consumer group and the Illinois attorney general have demanded a national recall, something the FDA said made no sense because it had no evidence suggesting that the formula would be dangerous for babies at the levels of contamination found.
After saying it made an error in its data, the FDA on Wednesday produced these results: Nestle's Good Start Supreme Infant Formula with Iron had two positive tests for melamine on one sample; Mead Johnson's Infant Formula Powder, Enfamil LIPIL with Iron had three positive tests on one sample for cyanuric acid.