Food and food safety are highly important topics in the society today. The food should be safe, healthy and sustainable in every way. Naturally, this also includes the food packaging, which is important both for food quality and shelf life, reduced food waste and for food safety. When it comes to food safety, it is required that all plastic packaging materials in contact with the food (Food Contact Materials - FCM) must be in accordance with the strict European regulations (EC 1935/2004 and EU 10/2011). Migration of chemical substances from the packaging to the food has to be below the given specified migration limits (SML). Substances classified as carcinogenic, mutagenic or reprotoxic (CMRs) should not be present at all.

There is high focus on food safety in all parts of the food production value chain, and the partners in the TREMM project have identified several challenges that are important for the industry to solve. The regulations are insufficient and difficult to follow, and the risk assessment for food contact materials is inadequate. More knowledge about chemical substances intentionally added to food contact materials and how they migrate into the food is needed. There is a lack of knowledge about chemical substances not intentionally added to the food contact material (NIAS), and how these migrates to the food. There is also a lack of analytical methods for determination of a huge number of chemical substances and NIAS components.

Collaboration project

The TREMM project is a collaboration project where companies from the food and food packaging industry work together with Norner Research and Nofima to solve the mentioned challenges. The partners from the industry represent both packaging producers, filling machine producers and food producers.

The main objective has been to investigate the migration of chemical substances from FCMs such as laminates, printed packaging materials and packaging intended for heating in microwave ovens. In addition to this, migration from food contact machine components, typically e.g in filling machines, classified as FCM have been investigated.

NIAS safety assessment

EU 10/2011 require that NIAS should be identified and give guidelines for how potential risk of these NIAS can be assessed. The project has developed a strategy and process for doing this based on Cramer Class classification.

Case study

In a case study 8 different multilayer packaging materials (laminated and/ or printed) were investigated, by using the two screening food simulants 95% ethanol and isooctane. The temperatures and migration time were adjusted to the intended packaging use as expected. We have found both IAS and NIAS in all 8 packages. The identified IAS and NIAS are well below the migration limits even at these harsh screening conditions.

Summary of results - IAS

Several IAS were found, all of these were identified and assessed against the SML from EU regulation 10/2011. Even under screening conditions, the migration was below the SML for all substances. Two of the substances found are typically used in adhesives (Iso-cyanates). They were found in three of the packaging samples which were adhesive laminates. Another substance, Tributyl acetylcitrate (ATBC), used as a plasticizer e.g in printing inks, was found in two of the packaging types, one laminate and one three-layer PE film. All other substances were well known polymer additives and monomers.

Summary of results - NIAS

NIAS are the most challenging to identify and there are various sources for NIAS. It can be side products, degradation products or contaminants. In this case study we found NIAS of different categories:

• Identified, known origin
• Identified, unknown origin
• Detected, but not identified

Among those NIAS we identified with a known origin, one groupe is saturated hydrocarbon. These are a natural part of the polymer. Two NIAS were similar to ATBC and were found in the same two packaging materials where ATBC was found. The other 5 NIAS substances were from additives or monomers including caprolactam dimer.

We identified some NIAS components with unknown origin. Possible origins could be adhesives, or printing inks. Analytical artefacts can also be a reason at the harsh conditions used.

Several unidentified substances were found which proves that identification of NIAS is very challenging. Most of these are very small and close to the 10ppb detection limit.

Project highlights

Successful development of analytical strategies for identification of NIAS in plastics packaging and validated methodology for risk assessment which is implemented at the institutes.

The project has analysed about 30 cases and identified many substances. Most substances are well known, allowed and within the migration limits. At harsh migration conditions, some identified substances need further assessment.

The industry partners have significantly improved understanding which can be implemented in own quality systems.

TREMM-project facts and figures

Safe Packaging Food and Migration (TREMM) is an Innovation Project for the Industrial Sector (IPN). The project lasts for 31 months (01.06.2018- 31.12.2020)

Project partners:

From the packaging value chain:

• Tommen Gram/Bewi, Producer and distributor of food packaging films
• Elopak AS, Producer of packaging and packaging machines for liquid food
• Orkla Foods Norway, Food producer
• Hoff SA, Food producer
• SCG Chemicals, Thailand, Producer of polymer materials for packaging applications 

R&D organisations with expertise in the food packaging value chain:

• Norner Research
• Nofima
• Tommen Gram/Finn Robert Muller is project responsible.
• Norner/Jorunn Nilsen is the project manager.