Fast food chains in Shanghai, including Pizza Hut, KFC and Papa John's, have said that they don't use the type of Italian mozzarella cheese which has been banned by China's quality watchdog for possibly dioxin contamination.
Dioxin, a carcinogen, was found in higher-than-permitted levels in products from 29 mozzarella makers by Italian authorities earlier this month.
Importers must immediately stop selling the cheese and recall products that have been sold, the General Administration of Quality Supervision, Inspection and Quarantine said at the weekend.
The Italian mozzarella cheese was not found in Shanghai's Carrefour and Fresh Mart which sells many imported foods. Four stores of Metro Jinjiang Cash &Carry Co stopped selling Italian mozzarella cheese on Saturday after receiving the notice.
"We will pay close attention to the issue and follow the further request of the quality departments," said Huang Zhongjie, Metro's national PR manager.
Some mozzarella cheese was found in City Mart but it was produced in New Zealand and Ireland.
Pizza Hut said it didn't use mozzarella cheese produced in Italy. Papa John's said the mozzarella cheese it used was produced in New Zealand, while KFC said the cheese it used didn't come from Italy.
Mozzarella cheese is a key ingredient in the best pizzas. Italy produces 33,000 tons of it every year, 16 percent of which is exported.
Italian authorities said that some mozzarella from the Campania region in the country's south contained more dioxin than permitted. They said contaminated feed given to cattle might be to blame.
The Chinese quality watchdog confirmed that mozzarella had been exported to China.
"Every batch of other kinds of cheese products from Italy must go through laboratory tests before they are allowed to enter the country," it said.
The watchdog has ordered all entry and exit ports in the country not to handle quarantine applications for Italian-made mozzarella and has asked all stores to stop selling it and recall the cheese.