Disclosure that laboratory tests done in the U.S. detected traces of contamination in several major brands of infant formula generated concern and confusion Wednesday.

A U.S. consumers' group and the Illinois attorney general have demanded a U.S. Food and Drug Administration recall, but the federal agency said it had released inaccurate information on what chemicals were found in which products.

As worried parents called manufacturers looking for guidance about the presence of melamine and another byproduct in U.S.-made formula, the FDA reiterated its position that baby food is safe, contending the extremely low levels of contamination do not present a health danger.

"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 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."

Confusion caused by FDA

Part of the confusion Wednesday stemmed from the FDA's own statements.

While proclaiming that the 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 the FDA released to the Associated Press, which was first to disclose the brand names of the formulas 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 put it in watered-down milk to falsely elevate protein levels. The concentrations in China were about 10,000 times greater than what the FDA found in the U.S.

No reports of illness

The FDA said there have been no reports in the U.S. of human illness from melamine. The chemical, which legally can be used in product packaging and as 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.

Mead Johnson spokesman Paradossi said he was frustrated the FDA issued inaccurate information.

He said the FDA informed his company of the test results, as well as the inaccurate disclosures on Wednesday, during an emergency conference call the agency staged with major manufacturers and the industry's trade group. During a similar call Monday, the FDA told the industry about the upcoming AP investigative report.

Nestle did not returns calls seeking comment Wednesday.

Illinois Attorney General Lisa Madigan called on the state's public health department and the FDA to recall Nestle and Mead Johnson products — and urged the companies to do voluntary recalls.

"The agency apparently withheld the results of its testing from the public for over three weeks, and then only disclosed the information in response to a FOIA request by the Associated Press," Madigan wrote in a letter to Michael Leavitt, secretary of the U.S. Department of Health and Human Services, which oversees the FDA.

FDA says recall not required

On the topic of a possible recall, the FDA's Leon said: "The agency would only seek to remove a product on the basis of a risk, based on scientific evidence. That's not what we're talking about here."

Consumers Union said 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."

Formula maker Abbott Laboratories, whose brands include Similac, told AP that in-house tests had detected trace levels of melamine in its infant formula. Those levels were below what the FDA found in the other formulas, an Abbott spokesman said, and below any nation's safety guidelines.

The three firms — Abbott Laboratories, Nestle and Mead Johnson — manufacture more than 90 per cent of all infant formula produced in the United States.