Food experts are concerned about the about millions of Styrofoam boxes that that are being used in the country every day with no tests having been conducted on them.
The concerns follow last week's finding by the Hong Kong-based International Food Packaging Association that half of all the food boxes in China, including paper, plastic and styrofoam ones, contained a large amount of certain powder that causes cancer.
Retailers in Ho Chi Minh City sell millions of styrofoam boxes every day to rice, sticky rice and dumpling shops.
Two retailers on Hai Thuong Lan Ong Street, District 6, said they sold styrofoam boxes at around VND350-500 apiece, or VND200-250 for large purchases.
"These boxes are every convenient. They are mostly made here in Vietnam," said one of the retailer who refused to be named.
A sticky rice shop on Kim Ma Street, Hanoi uses styrofoam boxes to serve both take-away customers and those eating at the shop. "That's convenient," the shop owner was quoted by Lao Dong as saying Wednesday.
Mai, selling rice in the Giang Vo residential area in Hanoi's Ba Dinh District, said her shop is small and her customers, mostly office workers, take the rice away in the styrofoam boxes.
"We've been using the boxes for many years and there's no problem. Look at that white box, it's soft and clean like that, how can it contain some carcinogen?" she told Lao Dong.
Huynh Le Thai Hoa, head of HCMC Food Safety and Hygiene Department, said that for the sake of safety, the styrofoam boxes should have been tested before being delivered on the market.
Hoang Lam, deputy director of QUATEST 3 the HCMC office of Vietnam's Quality Assurance and Testing Center, said the center has only tested food containers from abroad.
"Styrofoam boxes produced domestically are not subjected to any obligatory tests," Lam was quoted by the local newswire Vnexpress as saying Tuesday.
Tran Van Ky, a doctor from Vietnam Food Safety Association, said any kind of package must be tested and their safety and hygiene quality announced according to the Health Ministry regulations.
"If the styrofoam box is not tested and no one controls its quality, the consumers won't know what to do and have to leave things in the hand of luck then," Ky said.
Experts have advised people not to use styrofoam boxes for contain foods. China has banned styrofoam boxes suspecting they were made from waste.
Vu Tan Canh, an polymer and composite engineer from Vietnam Institute of Science and Technology, said the main material for styrofoam boxes is polystyrene, one of the most widely used plastics.
Polystyrene. when combined with oil, acid, salt or any salty substance will cause harm to human body and bacteria can grow in holes of the styrofoam boxes to spoil the foods, Canh said.
He said the producers could be using other additives that no one knows about, but in many cases these are plastic waste or heavy metals harmful to human body.
Food boxes made from polystyrene are banned in many countries.
When containing hot foods, the plastic will produce more toxins that can damage the liver and cause several other diseases, Canh said.
He said people must not ever keep hot food in any kind of plastic.