Food packaging migration is the transfer of chemical or fragments of components from packaging materials into food. This can happen from inks, adhesives, varnishes, coatings, or the packaging materials themselves. Migration is of relevance to smaller size components (below 1000 Da). The extent to which migration occurs depends on various factors:

• the physico-chemical properties of the migrant, of the packaging material, and the food (e.g. fat content)
• temperature
• storage time
• size of the packaging in proportion to the foodstuff volume (smaller size packaging has a larger surface to volume ratio).

The term “low migration” refers to inks that are suitable for indirect food contact applications. These inks are specifically formulated to meet required migration limits and compliant with Swiss Ordinance and Nestle Guidance Notes for Packaging Inks.

For ink formulation, ink for low migration applications is usually formulated with high molecular weight components, usually above 1000 Da. It is easy to achieve this threshold for traditional printing inks (screen, gravure, flexo, etc.). However, it is harder to formulate inkjet inks with these components. Hence, components are selected using industry guidelines and regulations.

Proving a product’s suitability for low-migration applications involves following standards and norms, rather than merely stating it is low-migration.

Regulatory organizations and large print consumers have created component lists for ink manufacturers to follow. The most used lists are:

• EuPIA – general guidelines and an exclusion list of components (European Framework Regulation (EC) No. 1935/2004 on materials and articles intended to come into contact with food)
• Swiss Ordinance (Ordinance on Materials and Articles in Contact with Food, SR 817.023.21 – an inclusive list of compounds.
• Nestlé Guidance Notes on Packaging Inks – exclusion list released and managed by the Nestlé Corporation. Inks that comply with this list are better known as “Nestlé Compliant”

Because an ink manufacturer cannot know or replicate all the substrate/food combinations for which a certain ink will be used, it can never guarantee that migration will not occur. As a result, the manufacturer of the finished packaging must conduct migration testing on each variation of packaging using a certified analytical laboratory.

An authorized laboratory may pick the appropriate food simulant for the type of food product to be packaged. Simulants include aqueous, acidic, ethanolic, semi-fatty, fatty, and dry foods.

Wikoff Digital continues to invest in R&D, innovative technologies, product stewardship, and regulatory compliance for sensitive packaging.  We are currently developing indirect food contact compatible inks for low migration.

We also work to educate all supply chain stakeholders, from raw material suppliers to graphic designers to printer converters to brand owners and retailers, on compliance, potential hazards, options, and opportunities. We also provide support to end users with in-house migration testing and connections with third party migration testing labs.

Reach out to us for more information on this project.