The US Food and Drug Administration defended the safety of infant formula sold in the United States on Friday despite tests that found the chemical melamine in one brand and a related compound in another.
The amounts found are far less than levels found in infant formula in China earlier this year and "do not raise public health concerns," said Stephen Sundlof, director of the FDA's Center for Food Safety and Applied Nutrition. "The domestic supply of infant formula is safe."
FDA tests found "very low levels" of the industrial chemical melamine in Nestle's Good Start Supreme with Iron formula, Sundlof said during a conference call. Low levels of cyanuric acid were found in Bristol-Myers Squibb unit Mead Johnson's Enfamil Lipil with Iron.
The agency said it had determined that levels of melamine or one of its related compounds, alone, below 1 part per million in infant formula were not a concern.
The FDA has so far tested 74 samples of US infant formula, a process that began in September when melamine was discovered in infant formula in China. It has 13 more to test.
Thousands of Chinese children were made ill and at least four died after developing painful kidney stones from formula contaminated with melamine, which has been used as a cheap substitute to boost the appearance of protein levels in milk and other products.
China's quality watchdog said it was seeking more information from its American counterpart on US-made infant formula on sale in China, the official Xinhua news agency reported on Friday.
Many parents in China shifted to US brands after the scandal involving tainted Chinese-made formula made headlines in September.
Sundlof said the FDA found an amount of melamine, a chemical used in the production of plastics and fertilizer, "10 thousand-fold less than the amounts associated with the Chinese infant formula contamination."
The FDA found melamine levels of 0.137 part per million and 0.140 part per million in tests on the Nestle sample and cyanuric acid levels of 0.247 part per million, 0.245 part per million and 0.249 part per million in the Mead Johnson product.
Melamine-tainted pet food that surfaced last year in the Unites States triggered thousands of complaints of sick or dead cats and dogs. Pets who ate contaminated food developed harmful crystals that either damaged or shut down their kidneys, and the FDA assumes that is the same issue with the infant cases in China.
