South Korean food security watchdog on Thursday said almost all vitamin C drinks sold in South Korea were found to contain benzene, a harmful chemical substance.

(South) Korea Food and Drug Administration (KFDA) detected the carcinogen, with the amount ranging from 5.7 to 87.7 ppb (parts per billion) in 27 out of 30 vitamin C drinks sold in the country, said the agency in a statement.

It is the second time for the food watchdog detected the substance in vitamin C drinks. In February, the KFDA said it discovered benzene in 36 out of 37 such kind of drinks.

Benzene is designated as a cancer-causing chemical by the International Agency for Research on Cancer and the World Health Organization (WHO). It is often detected in polluted air, subterranean water and food products.

South Korea limits benzene content to 10 ppb in drinking water. The United States and Canada curb it to 5 ppb while the European Union restricts it to 1 ppb.

The food watchdog agency said iron and copper in vitamin C drinks work as catalysts under certain conditions to form benzene from vitamin C preserve, benzoic acid natrium.

Only three products -- Kwang Dong Pharm Co.'s Vita 500, Lotte Pharm Inc.'s Vita Power and Sangil Pharm's Mega Vita -- had no benzene content. The companies avoided using benzoic acid natrium by adopting alternative manufacturing formulas, it said.

KFDA advised the manufacturers, whose drinks contain more than 10 ppb of benzene, to recall the products voluntarily. It also urged the companies to stop using benzoic acid natrium and find alternative production methods.

The watchdog plans to continue monitoring the benzene content of drink products overall and conduct further research on preventing the formation of benzene, it said.

Source: Xinhua