Chemicals used in McDonald's Chicken McNuggets were within official limits, China said Friday, after reports that excessive consumption could cause nausea, vomiting and even suffocation.

The State Food and Drug Administration (SFDA) disputed media reports that said chemicals in the popular chicken pieces, including an anti-foaming agent and a petroleum-based chemical, were a risk to health.

An SFDA statement said an investigation "did not find the content of tertiary butylhydroquinone in the McNuggets and its cooking oil exceeded the maximum amount" set by a national food additive standard.

As for the other chemical, dimethylpolysiloxane, authorities were working to come up with a set of testing measures due to a lack of a national standard, according to a statement posted on the agency's website.

During the investigation, samples were taken from McNuggets and cooking oil in 22 McDonald's restaurants in four provinces and municipalities, including Beijing and Shanghai.

Vivian Zhang, spokeswoman for McDonald's China, said last week that the food was safe and the additives were "common and fully-approved ingredients that are completely safe.”

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 Friday that 84 tons of melamine-tainted milk powder was seized in northwestern China in the latest such case to emerge.