The US Food and Drug Administration (FDA), in an alert notice on its official website, said that it will impound shipments of food that contain milk ingredients from China, in an attempt to control melamine contamination.

Melamine is an industrial chemical, which is used to make plastic and fertilizer, but often it is added to human and animal foods to boost protein readings. Consuming Melamine in large amounts can lead to kidney stones and even death. According to reports, Items like cookies, candies and other food items made with milk and milk products from China would be scrutinized by the FDA.

Steve Solomon, the agency's deputy associate commissioner for compliance and policy said the FDA is requiring importers of the halted shipments to test for the chemical and if an importer can prove his product is not tainted, FDA will release it. The agency will also increase its testing of products that are already in the market.

This announcement comes two months after Chinese dairy products were found containing melamine which resulted in the death of four infants and sickened 50,000 others.

FDA Commissioner Andrew von Eschenbach and Health and Human Services Secretary Mike Leavitt are to travel to China next week to meet with food safety officials there and open three offices. Solomon said, "We're taking regulatory action to make sure we're controlling these products."

The FDA said melamine in processed foods is unlikely to be harmful, as was the case with infant formula in China. "The finished product is not going to cause the same adverse affects," Solomon said. The FDA based this on the calculation of risk assessment of melamine and concluded that for products other than infant formula, levels of melamine below 2.5 parts per million do not raise public health concerns.

Caroline Smith DeWaal, director of food safety for the Center for Science in the Public Interest, a Washington-based advocacy group said, "Given the revelations of the extent of the problem in China, this step is both precautionary and appropriate. The question is, did FDA wait too long to stop the spigot?"

The European Union banned imports of Chinese dairy products for children and infants in September followed by several other countries, including Singapore and Russia. Melamine has been found in frozen yogurt, instant coffee, and chocolates sold in countries such as Singapore, New Zealand, South Korea, Spain, Yemen, Canada and the United States and recently the chemical has also been found in Chinese eggs and in fish feed.

Rep. Rosa DeLauro (D-Conn.), who chairs the appropriations subcommittee with jurisdiction over the FDA, said, "Clearly, the problems involving melamine in China are significantly deeper than FDA would have us believe," she said.

Tong Xun, a senior manager with the Zhangjiagang-based Liangfeng Food Co, said, "Compared to other countries that banned China's dairy products completely, US authorities seem to be more understanding of China's situation. I'm afraid it will take at least six months for us to recover from this difficult time," Tong said.