Hong Kong Center for Food Safety ( CFS) recently conducted a study to assess the safety and suitability of the containers used to hold instant cup noodles commonly available in Hong Kong for holding food, a CFS spokesman said Thursday.

"Instant cup noodles are popular in Hong Kong. Some chemical residues in the containers, if they migrate to food, may affect health," the spokesman said.

"Those of most concern are styrene monomer used to make polystyrene, a material of the containers; heavy metals which are impurities; and diaminotoluene, a contaminant that may remain in the lids of containers made of composite laminated films," he said.

"Other substances, such as additives and impurities, may also migrate to food. The total amount of migration of all these substances to food can be reflected by the total migration level," he added.

The CFS collected samples of 52 instant cup noodle products of various countries and areas from local supermarkets, chain stores, department stores, and groceries to identify the contact materials in the cups and lids. Among them, 30 products of the most common brands were tested on their safety and suitability. The testing parameters included total migration, heavy metals, styrene monomer and diaminotoluene.

Thirty sets of cup and lid were tested for total migration. All levels detected were well below the limit of 0.5 mg per square inch set by the U.S. Food and Drug Administration (FDA). No samples were found to contain heavy metals.

A total of 11 cups and 5 lids made of polystyrene, expanded polystyrene, or containing polystyrene coating, were tested for styrene monomer. The levels of styrene monomer ranged from not detected to 1,000 mg per kg of the sample, or 0.1 percent, which were within the limit of 0.5 percent of total residual styrene monomer set by the FDA. No diaminotoluene was detected in lids made of composite laminated films.

"Results of the study showed that all samples of containers complied with the FDA standards for total migration and styrene monomer and that no heavy metals and diaminotoluene were detected. If properly used, the containers are suitable for holding instant cup noodles and unlikely to pose any food safety problem," the spokesman said.

"People are advised to follow the instructions on the package properly and refrain from preparing noodles with boiling water in a damaged or deformed container," he said.

"The food trade is reminded to source containers from manufacturers who follow good manufacturing practice (GMP), and choose products that are safe and suitable for the intended use. Do's and don'ts in preparing the noodles should also be given clearly on the package," the spokesman stressed.

(Xinhua News Agency May 7, 2009)