CHINA – To keep food clean and fresh, and reduce the use of plastic bags, consumers are increasingly willing to bring food containers when they go shopping in wet markets and restaurants.

As useful as food-storage containers can be for meal preparation and transportation, and though they can store food well for an extended period of time, a recent survey has shown that many of those seemingly safe containers may have hazardous chemicals lurking inside.

TÜV Rheinland, one of the world’s leading testing and certification service provider founded 150 years ago, recently conducted tests on food containers for non-intentionally added substances (NIAS).

According to the company, results from the study indicated that all tested polypropylene (PP) food containers purchased in various department stores in China have different degrees of health hazards for consumers.

TÜV Rheinland tests detected substances in the samples, who’s some of their structures have not yet been known while other identified chemicals were found to exceed the Threshold of Toxicological Concern (TTC).

TTC is the commonly used preliminary risk assessment method for the toxicity of trace amounts of chemicals.

The basic concept of TTC is to establish generic exposure level for most chemicals with known structures (i.e. Threshold values) below which there would be acceptable risk to human health.

If the amount of the chemical substance is higher than the threshold value, performance of further risk assessment is recommended.

According to the tested results, polypropylene food containers were found to be releasing non-intentionally added substances which the company claims may cause health related problems.

NIAS may be a certain chemical substance such as an impurity from substance that can be added from an approved list, or a by-product or pollutant generated during the production process.

However, in most cases, food manufactures and packaging suppliers have no full control over the presence of NIAS.

“The presence of these unintentionally added substances should not be taken lightly, as the toxicity of these chemicals have not been assessed yet. They can range from being safe to very toxic in trace amounts,” TÜV Rheinland opines in the report.

The company has hence called on manufacturers of food packaging to increase their safety awareness in regard to NIAS in their products.

“In addition, manufacturers should use high-quality raw materials and maintain traceability information regarding the ingredients of the raw materials.

“Of course, adopting Good Manufacturing Practices (GMP), and maintaining good communication between the different parties involved in the full manufacturing chain is critical to producing high-quality products,” the company adds.

The common testing approach in the past has been to check only for target substances according to the known plastic material types or the ingredient information manufacturers use in the production process.

Infact, EU regulation require that non-intentionally added substances should also be assessed to be sure that the materials utilized in the manufacture of the packaging are safe when in contact with food.

However, there is currently no official standardized method for NIAS testing, and not all found substances can be identified by any existing single laboratory technique.