Disclosure that laboratory tests have detected traces of contamination in several major brands of infant formula generated concern and confusion Wednesday.
A national consumer's group and the Illinois attorney general demanded the Food and Drug Administration issue a recall but the federal agency acknowledged it had released inaccurate information on what chemicals were found in top selling products.
As worried parents called manufacturers looking for guidance about the presence of melamine and a key byproduct in U.S.-made formula, the FDA reiterated its position that the baby food is safe and parents should continue feeding it to their babies, contending the extremely low levels of contamination do not present a health danger.
Also, a spokesman for one major manufacturer criticized the FDA for its release of the inaccurate information.
"We're getting inundated by calls from moms confused about the situation," said Pete Paradossi, a spokesman for Mead Johnson, one of the three major manufacturers of U.S.-made formula involved in the problem detections.
Melamine is the industrial chemical found in Chinese infant formula - in far larger concentrations - that has been blamed for killing at least three babies and making at least 50,000 others ill.
The FDA and other experts said the melamine contamination in U.S.-made formula had occurred during the manufacturing process, rather than intentionally as was done in Chinese production. The manufacturers insist their products are safe.
"The levels that we are detecting are extremely low," said Dr. Stephen Sundlof, director of the FDA's Center for Food Safety and Applied Nutrition. "They should not be changing the diet. If they've been feeding a particular product, they should continue to feed that product. That's in the best interest of the baby."
Part of the confusion Wednesday stemmed from the FDA's own statements.
While proclaiming that the very low concentrations detected of melamine and a similar compound called cyanuric acid pose no health danger to infants, the FDA has maintained it is unable to identify any exposure level of melamine in infant formula "that does not raise public health concerns."
Further complicating the situation was inaccurate data that FDA released to The Associated Press, which was first to disclose the formulas' brand names and other details in an investigative report Tuesday.
A spreadsheet the AP obtained from the FDA under a Freedom of Information Act request stated that Mead Johnson's Infant Formula Powder, Enfamil LIPIL with Iron contained traces of melamine.
On Wednesday, FDA spokeswoman Judy Leon said that spreadsheet contained an error - that the FDA had incorrectly switched the names of the Mead Johnson product with Nestle's Good Start Supreme Infant Formula with Iron. That meant, Leon said, that the Nestle's Good Start had melamine while Mead Johnson's Enfamil had traces of cyanuric acid.
The FDA said last month that the toxicity of cyanuric acid is under study, but that in the meantime it is "prudent" to assume that its potency is equal to that of melamine.
Problems with melamine-spiked formula surfaced this fall in China, where unscrupulous manufacturers intentionally dumped it into watered-down milk to falsely elevate protein levels. The concentrations in China were as much as 2,500 parts per million - about 10,000 times greater than what the FDA found in the U.S.
The FDA said there have been no reports in the United States of human illness from melamine. The chemical, which legally can be used in product packaging and a solution to clean manufacturing equipment, can bind with other chemicals in urine, potentially causing damaging stones in the kidney or bladder and, in extreme cases, kidney failure.
At the same time, Illinois Attorney General Lisa Madigan called on the state's public health department and the FDA to recall both the Nestle and Mead Johnson products - and urged the companies to take that step regardless of what any government agency does.
Consumers Union said that the FDA's assurances are of small comfort to parents and caregivers.
"The FDA originally said there was no safe level for these contaminants in infant formula. So this formula is contaminated," said Jean Halloran, the group's director of Food Policy Initiatives. "It is very disturbing to us that no recall has been requested."
She urged the FDA "to immediately make public all of the results of its tests for melamine contamination in food," even those with levels below what would trigger agency action."
Rep. Bart Stupak, D-Mich., a frequent critic of the FDA, also has called for recalls.
The three firms - Abbott Laboratories, Nestle and Mead Johnson - manufacture more than 90 percent of all infant formula produced in the United States.