US fast food giant McDonald's said Friday it was working with Chinese authorities to test its Chicken McNuggets after reports said they contained risky additives, but stressed they were safe.
China's food regulator said this week it was testing the McNuggets after media reports said an anti-foaming agent and a petroleum-based chemical were used in the chicken pieces.
"We are fully cooperating with them," Vivian Zhang, spokeswoman for McDonald's China, told AFP in a statement.
The chemicals, dimethylpolysiloxane and tertiary butylhydroquinone, could cause nausea, vomiting and even suffocation if taken in excessive amounts, reports said.
Zhang said only "a fractional amount of legal preservative and a miniscule drop of an additive" were used in vegetable oil to prevent foaming on the surface "that naturally occurs in cooking".
"Customers can be reassured that these are common and fully-approved ingredients that are completely safe and have been used for decades," she said.
However, a survey showed the matter had hit confidence in McDonald's among Chinese consumers. The survey by Chinese portal Sina.com found that more than 75 percent of its 34,000 respondents said they would "definitely not eat foods like McNuggets any more".
China is regularly hit by product safety scandals despite government pledges to clean up the food industry.
In 2008, the industrial chemical melamine was found in the products of 22 Chinese dairy companies in a massive scandal blamed for the deaths of at least six infants and for making 300,000 others sick in China.
State media reported on Friday that 76 tonnes of melamine-tainted milk powder had been seized in northwestern China in the latest such case to emerge.