China has sent back more than 100 metric tons of American milk powder after it was found to contain potentially dangerous levels of nitrite.
The General Administration of Quality Supervision, Inspection and Quarantine said that 102 tons of milk powder, worth US$200,000, had been returned to US manufacturer West Farm (Darigold).
Three batches of the powder imported by a Chinese company had registered nitrite levels of 2.7mg/kg, 2.8 mg/kg and 4.4mg/kg. China's national safety limit for nitrates in food stuffs is 2 mg/kg.
AQSIQ issued a warning following the case, calling on local quality inspection bodies to step up inspections of imported milk powder to ensure consumer safety.
China imports large quantities of milk powder to supply rising demand for dairy products and other processed foods. But previous cases of contamination, leading to fatal incidents, has made the government more sensitive to its safety.
In 2004, at least 13 babies died of malnutrition and nearly 200 fell ill after they were fed with a fake milk power made in East China's Anhui Province.
Another food safety incident is also raising awareness of the need for China to improve standards. Beijing hospitals are currently dealing with a wave of meningitis caused by consumption of raw or partially cooked snails. The Health Bureau has said that 87 people are ill after eating the dish at the Shuguo Yanyi Restaurant in recent weeks.