China's food and drug watchdog has dismissed worries from the owners of hotpot restaurants who fear attempts to ensure excessive amounts of additives are kept out of foods will lead to them having to disclose their secret formulas.

The State Food and Drug Administration (SFDA) said some hotpot outlets might have misunderstood the decree, which does not demand that restaurants give up their secret recipes, reported the Guangzhou Daily on Sunday, quoting the press office of the SFDA.

The decree, published on April 27, was intended to ban inedible additives used in foods and curb the excessive use of legal food additives, the SFDA added.

By the end of this month, restaurants nationwide must reveal any additives used in hotpot soup flavoring, beverages and seasoning to the food watchdog as well as post information in conspicuous locations within restaurants or print it on menus, says the decree.

Restaurants should also honestly respond to customers' inquiries about additive use, it added.

Media reports said earlier that an additive-rich flavoring for spicy hotpot soup, called "one drop aroma", was widely used at hotpot outlets nationwide. The flavoring has been found to be highly dangerous to human health if taken in large quantities.

Calls to the SFDA went unanswered on Monday because it was a holiday in China.

For some hotpot outlets, however, the decree does not have an impact on them at all.

"We don't need to use additives at our restaurants," said Li Haixia, operation director with the Beijing Hongyuan Dining Management Company, which runs eight hotpot branches featuring light-flavored hotpot soup and offering mildly spicy seasoning.

In South China's Guangdong province, the local food watchdog said at the weekend that restaurants will be ordered to shut down if they are found to offer food containing illegal inedible additives.

"We're more worried about the use of additives by raw-material suppliers," said Xiang Weixuan, owner of the Xinxian Hong Kong Style Hotpot in Guangzhou.

Xiang said his restaurant will try to use a minimum of additives but risks remain that suppliers will not tell him about the amount of additives they have used in raw materials.