NANNING - Tight regulations need to be issued to control China's traditional Chinese medicine sector, experts said at a just-concluded conference held in the wake of a major industry scandal.

A mechanism should be established to measure the contents of TCM products and ensure their safety, said Luo Jiabo, dean of the Chinese Medicine College of Southern Medical University, at the event.

"The government should also tighten its supervision of TCM manufacturers," he said during the three-day 2013 China-ASEAN Summit Forum on Traditional Medicine, which concluded on Sunday in Yulin city of South China's Guangxi Zhuang autonomous region.

Luo's remarks came after Chinese media outlets exposed dodgy TCM practices that have shocked consumers and seriously damaged the reputation of the industry.

In March, the Guangdong Baoshantang Pharmaceutical Co Ltd, a medicine manufacturer in southern Guangdong, was reported to be using cheap but ineffective herbal materials to produce Vitamin C Yinqiao Tablets, one of the most commonly used cold medicine in China.

In addition, the raw herbal materials purchased by the now-disgraced company were found to have been smoked by sulfur to keep them fresh.

Smoking herbal materials in this way for preservation purposes is a dirty secret in the industry, but the common practice can leave a certain amount of sulfur dioxide in the materials, Luo said.

According to the dean, some greedy retailers store large amounts of herbal materials and smoke them with sulfur to stop them getting mildewed, and the sulfur dioxide left on them can damage consumers' livers and kidneys if they are taken in big doses over a long time.

The World Health Organization recommends a daily sulfur intake of no greater than 0.7 mg per kg of body weight. Long-term exposure to high amounts of sulfur dioxide can damage the human body, especially the respiratory system, according to experts.

Huang Hanru, deputy director of the China Medical Association of Minorities, said it is necessary to guarantee the quality of TCM products at the industry's root, which is medicinal herb growers.

"The government should enhance education among growers to prevent the raw materials from being contaminated," he said.

He added that medicine manufacturers should strengthen their sense of responsibility, and that any manufacturer found making illegal or unqualified TCM products should be severely punished in accordance with the law.

A national standard for the amount of sulfur dioxide left on TCM products will soon be published, in an attempt to curb the abuse of sulfur in the industry following the scandal, according to the country's food and drug watchdog.