KFC's fried chicken wings. [File Photo: dianping.vchi.cn]

Kentucky Fried Chicken, the US fast food giant has again sparked food safety concerns around China, with its outlets being accused of repeatedly using same frying oil for as many as 10 days, which experts believe may cause cancer.

The Guangzhou-based Information Times reports that KFC branches in some cities in northwest Shaanxi Province have been discovered putting Magnesium Trisilicate into frying oil to prolong its usage. Magnesium Trisilicate is a white, odorless and tasteless powder, which can decolorize and absorb the odor and some impurities of the overused turbid oil, as well as reducing its acidity and oxidization. After being "polished," the cooking oil is used over and over again for up to 10 days by some KFC outlets in Xianyang city, Shaanxi Province.

However, the KFC Corp (China) claimed on Thursday that the overused oil is concern-free as it is in compliance with the national food safety standard. It argues that the "oil purifier" is approved by the US Food and Drug Administration as a safe aide substance. Experts with the World Health Organization and Food and Agriculture Organization of the United Nation all agree that the powder purifier can be used as food additive. KFC Corp (China) argues it will stop using it the time it is found to breach China's food safety standard.

Despite KFC's defense, food experts have not yet being convinced as they believe that even if their additive itself is safe, repeatedly used oil is no longer safe. Harmful substances will be produced after being heated time after time. Acrylamide and Benzopyrene, for instance, could always be two types of harmful side-products from frying French fries and chickens. These two side products are widely believed to cause cancer.

Health authorities in Xianyang, Yulin, and Xi'an, three local cities of Shaanxi Province, have inspected KFC outlets and confiscated their "oil powder". The provincial health administration has also reported the case to the Health Ministry for further investigation.

In similar response, local health authority of southern China's Guangzhou, has also decided to inspect cooking oils in all KFC outlets in the city.

This is the third time KFC has been involved in food safety panic in China. In March 2005, Sudan 1, a kind of carcinogenic food dye, was discovered in New Orleans roast chicken wings, a popular food produced by KFC. Last November, KFC's safety scare emerged again in China after KFC outlets in the US were found to be using artificial fats although KFC Corp (China) said then it cooked its fried chickens in a healthier edible oil, which did not contain the harmful trans-fatty acids used in US branches of KFC.