Food Packaging Migration Testing: What Companies Need to Know

Food packaging must be safe and must not transfer substances to food in quantities that endanger human health or unacceptably affect the quality of the food. But which legal foundations actually apply? Which food simulants must be selected for migration testing? And how can results from migration tests be properly evaluated?

That was precisely the focus of the web seminar “Migration Testing on Food Packaging” with speaker Dr. Tim Schlüter. The objective was to provide a practical overview of the fundamentals and, in particular, to help participants better understand test reports and declarations of compliance and verify them for plausibility.

From the Framework Regulation to the Plastics Regulation

An important foundation is established by Regulation (EC) No 1935/2004. It sets out general requirements for materials and articles intended to come into contact with food. Under normal or foreseeable conditions of use, materials must not transfer their constituents to food in quantities that endanger human health or bring about an unacceptable change in organoleptic characteristics.

For plastics, these requirements are specified in detail by Regulation (EU) No 10/2011. A central role is played by the Union list of authorised substances. This includes substance numbers, specific migration limits (SML), group restrictions, and instructions for compliance testing.

Overall Migration and Specific Migration

In the web seminar, a distinction was made in particular between two types of migration testing.

Overall migration measures the total amount of non-volatile substances that migrate from a material or article into a food simulant. The limit explained in the seminar was 10 mg/dm² of food contact surface.

Specific migration, on the other hand, deals with individual known substances. Specific migration limits, known as SML values, may apply to them. In addition, group restrictions may exist where multiple substances must be assessed together.

Do Not Lose Sight of NIAS

Another key topic was NIAS, Non-Intentionally Added Substances. These are substances that are not intentionally added, such as impurities, contaminants, and reaction or degradation products from the manufacturing process. These can also be relevant for evaluating a food contact material.

In the context of the supply chain, Tim Schlüter also emphasized how essential it is to pass on sufficient information. Only when the necessary information regarding substances and potential restrictions is available can the downstream stage of the supply chain adequately assess the compliance of its material.

Food Simulants: Which Food Is to Be Simulated?

As migration tests cannot always be carried out analytically directly on the food itself, defined food simulants are used. In the web seminar, simulants A, B, C, D1, D2, and E were presented, among others. They represent different food characteristics, such as aqueous, acidic, alcoholic, fatty, or dry foods.

Which simulants are required therefore depends significantly on the intended application of the packaging. Correction factors and potential exemptions must also be taken into account during the evaluation.

Test Conditions Must Fit the Application

It is not only the food, but also contact time and contact temperature that influence migration. Therefore, test conditions are chosen to cover the worst foreseeable conditions of use.

A particularly important note from the web seminar: The test conditions for overall migration and specific migration are generally not identical. If they match in a declaration of compliance, it should therefore be checked whether this is plausible for the specific application.

This is precisely where the practical benefit of a fundamental understanding of the regulations becomes apparent. Anyone who knows which simulants and test conditions are relevant to their specific application can better comprehend and challenge statements provided by suppliers.

Correctly Evaluating Migration Testing

There are also several factors to consider after the actual test. For the evaluation, aspects such as the actual ratio of packaging surface area to food quantity, the intended application, re-use concepts, or packaging composed of multiple components may be relevant.

For multi-component packaging, it must also be checked whether identical migration-relevant substances could originate from different components. In the web seminar, this was illustrated using the example of packaging consisting of a tray and lidding film.

Conclusion: Knowing What Was Tested and Why

Migration tests are a complex topic. It is therefore all the more important to be familiar with the fundamental principles. Which regulation applies? Which substances must be considered? Which food simulant reflects the subsequent application? Which test conditions are required, and how was the result evaluated?

Above all, the web seminar demonstrated one thing: Not every detailed rule needs to be memorized. What matters is knowing where to find the requirements and which questions to ask when reviewing a declaration of compliance or a test report. It is precisely this understanding that helps to better contextualize results and assess the compliance of food contact materials on a more sound basis.