The Ministry of Health denied an allegation on Friday that the national standard on the maximum limit of melamine in baby milk formula is laxer than the level newly set by an international organization.

The Codex Alimentarius Commission has set a maximum limit of 0.15 mg/kg for melamine in liquid infant milk, according to a news release on the website of the World Health Organization on Wednesday.

The commission, jointly run by the UN Food and Agriculture Organization and the WHO, sets international food safety and quality standards as reference for its members.

However, the new standard has caused concern among Chinese consumers as the country last year set its national cap on melamine concentration in powdered baby formula at 1 mg/kg.

"China's national standard is actually in line with the international one," the ministry said in an online statement issued on Friday.

The statement explained that the new international standard is for liquid milk products while China's is for powdered formula. It said it is an international practice to dilute powdered formula by seven times the quantity of water, so 0.15 mg/kg for liquid is about the same as 1 mg/kg for powder products.

The ministry also noted that the commission adopted a maximum level of 1 mg/kg for powdered infant formula and 2.5 mg/kg for other milk products two years ago.

However, Liu Linlu, a mother in Beijing, said despite the ministry's explanations, she will still feed her 2-year-old son with imported formula.

In 2008, melamine-contaminated formula killed at least six babies and sickened some 300,000 on the Chinese mainland, according to official figures. Melamine, an industrial chemical, was illegally added to raw milk to boost fake protein readings in quality tests.

Wang Dingmian, former vice-chairman of the Guangdong Dairy Industry Association, said there are about 300 substances in pure milk, but melamine should not be one of them.

"It is a crime to artificially add melamine to milk," he said. "The official standard on melamine serves as the limit for melamine detected in milk as a result of environmental pollution."

"If the feed for cows and the living environment for cattle contains melamine, it can result in melamine in milk they produce," he explained.

Contact the writers at shanjuan@chinadaily.com.cn and hedan@chinadaily.com.cn