While Taiwanese media have recently reported that several disposable chopsticks imported from Vietnam have been found containing toxic chemicals, Vietnamese makers of the common utensils assert that they have never used any toxins in production.

Earlier this year Taiwanese media, citing the island’s Food and Drug Administration, reported that some 17,000 metric tons of made-in-Vietnam disposable chopsticks could contain biphenyl or hydrogen peroxide.

Biphenyl is a preservative, whereas hydrogen peroxide is a bleaching agent, long-term exposure to both of which can cause serious negative health effects, including liver damage, according to the Taipei Times.

Similar reports from Taiwan’s media have made Vietnamese chopstick makers unhappy, as they will affect their reputation when it comes to working with other international partners.

This has prompted Vietnam’s own food safety watchdog to review the manufacture of the products internally.

The Vietnam Food Administration (VFA), under the Ministry of Health, has called on their Taiwanese counterparts to provide information regarding the Vietnamese firms that have manufactured the allegedly toxic chopsticks.

“Unfortunately they only gave us the phonetic names of the firms, so we have yet to be able to identify who they are and inspect their products,” VFA head Nguyen Thanh Phong told Tuoi Tre (Youth) newspaper on Monday.

The Vietnamese National Institute for Food Control has also taken samples of ten types of disposable chopsticks in the domestic market, but none of them tested positive for either biphenyl or hydrogen peroxide, Phong added.

In the meantime, Vietnamese chopstick makers said they had never heard of hydrogen peroxide before.

“This is the first time I have heard of such an agent,” said Tran Quoc Manh, chairman of Sadaco, a Ho Chi Minh City-based chopstick manufacturer and exporter.

“Vietnamese chopstick businesses never use such a chemical in their production.”

Manh added that relevant Vietnamese agencies should clarify whether the chopsticks found containing toxins in Taiwan are really made-in-Vietnam products because Vietnamese disposable chopsticks are “made under international standards and qualified to enter such strict markets as Japan, the EU and the U.S.”

Vo Hoang Anh, director of marketing with Saigon Co.op, Vietnam’s largest supermarket chain, also said local consumers should not be worried as the company’s stores only sell chopsticks supplied by Sadaco.

“The chopsticks are made from domestic, rather than Chinese, materials,” he said.