The country's top quality watchdog this weekend strongly disagreed with a warning by the US Food and Drug Administration (FDA) over the safety of Chinese toothpaste, saying it was "unscientific, irresponsible and contradictory".

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In response to an FDA notice saying toothpaste made in China may contain a poisonous chemical, the General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) said in a statement that it is safe to consume the chemical in question in small quantities.

"Our research shows that toothpaste containing up to 15.6 percent diethylene glycol, the chemical that the US side is concerned about, is safe, even after prolonged use," the statement said.

The US started checking Chinese toothpaste imports on May 23 as media reports that the products may contain diethylene glycol, a solvent sometimes used as a substitute for glycerin, a sweetener used in drugs.

After finding Chinese toothpaste containing 3-4 percent diethylene glycol, the FDA on Friday issued a warning about toothpaste made in China.

However, experts from the Chinese Health Ministry said that diethylene glycol is a "low-level" poison that does not accumulate in the body, and said there is no evidence that it can cause cancer or deformities.

The AQSIQ also said that a list of the ingredients in the toothpaste exported to the US had been offered to the FDA. The list included diethylene glycol. Also, the toothpaste's labeling had already been registered with the FDA, meaning it could be sold in the US.

"Therefore, the FDA warning is unscientific, irresponsible and contradictory," the AQSIQ said. "We've lodged a representation to the FDA and asked it to clarify the facts in a scientific manner as soon as possible."

Joseph Famulare, an official with the FDA's center for drug evaluation and research, who was in Beijing attending a workshop this weekend, told China Daily that the US laws ban diethylene glycol as an ingredient in toothpaste.

He said recent safety scandals highlighted the importance of being aware of all the ingredients and intermediates in products.

To improve the quality of management and the regulatory framework for drug manufacturing, he said the FDA and Peking University had jointly launched a new graduate program on pharmaceutical engineering management.