The competent authorities will also examine the conditions, production procedure and raw materials of disposable bamboo chopsticks and toothpick producing enterprises in Vietnam.

The move is made after the Chinese media said that disposable bamboo chopsticks may be very harmful to the health of users. 

Earlier, Chinese actor Huang Bo posted a message on his micro blog saying that when he tried to wash the disposable chopsticks provided to him in a restaurant, he was astonished to find that the chopsticks turned the water yellow and gave off a pungent smell.

"Stop using disposable chopsticks, it is not about saving the environment anymore, it is about saving your own life," Huang wrote on the micro blog. The message was forwarded 125,000 times. 

Angry netizens asked Huang to reveal the name of the restaurant, Huang said the bad chopsticks are not only provided in that one restaurant, but are widely distributed.

Dong Jinshi, secretary-general of the International Food Packaging Association, said the color and smell of the chopsticks may indicate that they were exposed to sulphur and other chemical substances. "Sulphur, hydrogen peroxide, sodium sulfite and mold inhibitor, are chemical substances commonly used to make disposable chopsticks, even though they are not allowed," he said.

In Vietnam, the majority of disposable chopsticks in restaurants are imported from China, through the land border, so they are not tested for quality and cooking safety. Bamboo chopsticks are prone to mold so it is possibly that they contain unsafe preservative against mold.

Vietnamnet