US regulators set a safety threshold Friday for the industrial chemical melamine that is greater than the amount of contamination found so far in US-made infant formula.

US Food and Drug Administration officials set a threshold of 1 part per million of melamine in formula, provided a related chemical isn't present. They insisted the formulas are safe.

Chemist Michael Filigenzi demonstrates how vials of liquefied pet food are placed in trays for testing for the industrial chemical melamine at the California Animal Health and Food Safety Laboratory, at the University of California, Davis, campus in Davis, Calif., November 18, 2008. Traces of melamine have been detected in samples of top-selling U.S infant formula. [Agencies]

The setting of the standard comes days after it was reported that FDA tests had found traces of melamine in the infant formula of one major US 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, had been 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.

Though Dr. Stephen Sundlof, FDA's director of food safety, said Friday that there had been no new scientific studies since October that would give regulators more safety data, he said the agency was confident in setting the 1 part per million level for either of the chemicals alone. The level is the same as public health officials have set in Canada and China.

Sundlof emphasized that neither of the two tainted samples had both contaminants. He had no ready explanation for why the level wasn't set earlier.

Sundlof said the lack of dual contamination was key because studies so far show dangerous health effects only when both chemicals are present.

The agency still will not set a safety level for melamine if cyanuric acid is also present, he said.

"The levels were so low ... that they do not cause a health risk to infants," Sundlof said. "Parents using infant formula should continue using US-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.

Separately, a third major formula maker, Abbott Laboratories, said that in-house tests had detected trace levels of melamine in its infant formula.

Those three formula makers manufacture more than 90 percent of all infant formula produced in the United States.

The FDA said it had analyzed 74 samples and was continuing to examine 13 more.

The agency had left the impression of a zero tolerance on Oct. 3 when it stated: "FDA is currently unable to establish any level of melamine and melamine-related compounds in infant formula that does not raise public health concerns."

The FDA and other experts said the melamine contamination in US-made formula had occurred during the manufacturing process, rather than intentionally. The US government quietly began testing domestically produced infant formula in September, soon after problems with melamine-spiked formula surfaced in China.

Melamine can legally be used in some food packaging, and can rub off into food from there. It's also part of a cleaning solution used on some food processing equipment.

There is a gap between the concentration that the FDA detected in formula and the agency's estimate of how much melamine could contaminate food from the manufacturing process. The expected contamination from processing, 15 parts per billion, is about one-tenth the amount that the agency has detected in infant formula. FDA officials have not responded to questions this week about how that gap might be explained.

The agency said it is continuing research on animals to see the effects of ingesting both melamine and cyanuric acid.

(China Daily via Agencies December 1, 2008)