Quality supervisors have returned more than 100 tons of American milk powder after it was found to contain potentially dangerous levels of nitrate.

The General Administration of Quality Supervision, Inspection and Quarantine yesterday said 102 tons of milk powder had been returned to the United States.

The administration said the powder, worth US$200,000, had not entered the Chinese market.

Following the discovery of excess levels of nitrate in the milk powder, the administration issued a warning, urging local quality inspection bodies to step up inspections of imported milk powder to ensure consumer safety.

Experts warned excessive consumption of nitrite-tainted foods can cause poisoning and may even result in death.

The Beijing Entry-Exit Inspection and Quarantine Bureau examined three batches of the milk powder, produced by US company West Farm Inc, on June 7 and June 14. The three batches 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.

Li Yuanping, the administration's food safety director, said the milk powder was imported as a raw material for food production.

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.

China has been  struggling to control a rise in the number of food-related health scares in recent years.

(For more biz stories, please visit Industry Updates)