Low migration in UV label printing – part 1

An increasing number of food products are manufactured on an industrial scale and sold through retail chains. As a result, their manufacture and sale are subject to ever stricter regulations. Virtually all countries now have detailed food safety standards. Given that around half of all food products are packaged, food contact materials – such as the label – are subject to regulations just like the actual product, its ingredients and the associated declaration. A series of three articles aims to explain how label printing is affected, the consequences and how the situation is successfully dealt with in practice, taking the European market as an example. This first article focuses on the basic relevance of regulations for label printers.

Food contact materials and migration 

The umbrella regulation for manufacturing and marketing food products is the food safety regulation (EC) 178/2002. There are also a number of subordinate regulations relating to food contact materials and their manufacture. The European Food Safety Authority (EFSA) designates all items that are intended to come into contact with food as food contact materials. These items must be manufactured in such a way that they cannot transfer anything onto the food that is harmful to health, causes any unacceptable change in the products or has an organoleptic (Sensory properties such as taste, smell, colouring, etc. Wikipedia)  effect on them. The main regulations are as follows:

-       Food Contact Materials (EC) 1935/2004

-       Plastics (Plastic Implementation Measures) (EU) 10/2011

-       GMP (Good Manufacturing Practice) (EC) 2023/2006

According to the EFSA definition, labels can also fall into the category of food contact materials and be subject to the relevant regulations. Indirect food contact due to the migration of ink components, for example, is deemed equivalent to direct food contact in the regulation. The EU regulations currently in force no longer make any differentiation between primary, secondary and tertiary packaging. The risk of migration, that is to say the unwanted transfer of packaging components onto the food, is therefore of key significance in determining the production methods for a label.

Fig. 1: Types of migration (red border = of primary relevance in label printing)

Diffusion and set-off migration are the main risks with labels and there is a particularly high risk of UV ink migrating. Standard UV ink formulations are not ideal for use on food contact materials and can result in a significant risk of migration. However, the printing substrate and auxiliary materials such as cleaning media, oils, greases, plasticisers from inking rollers and printing plates, etc. also need to be taken into account when assessing the level of risk.

Who bears responsibility?

In principle, the person or company marketing a product is legally responsible for ensuring that the manufacturing process complies with the regulations for both food (contents) and packaging. However, partial responsibilities relating to the various packaging components are normally delegated to suppliers by means of a conformity declaration. All manufacturers of packaging components are thus required to produce the items they supply in accordance with the applicable regulations and confirm this by submitting a conformity declaration. This means that label printers are obliged to manufacture labels in accordance with GMP guidelines and ensure that the label's migration values comply with the relevant regulations.

This sounds relatively straightforward in theory but is far more difficult in practice. The main problem is that proof of conformity cannot be provided directly during label manufacture but only after a time-consuming process performed by an accredited institute. What's more, the relevant migration properties depend on the contents, the packaging's barrier properties, the storage conditions, the durability of products and their subsequent processing. And in practice label printers seldom know all these parameters and will rarely be able to provide analytical proof that migration values are complied with for every order. Reliable proof of conformity is thus only possible through cooperation along the entire value added chain.

Fig. 2: Self-assessment based on a simplified migration risk scenario

In addition to the legal consequences, manufacturers of branded goods and retail chains above all fear a loss of image. Many of the large food manufacturers and retail chains have therefore already developed house standards derived from the EU regulations that are applied accordingly within the value added chain (e.g. Nestlé, REWE and McDonalds).

Low-migration UV label printing 

Low-migration ink systems promise a way out of this situation, but don’t expect a standard or EU regulation relating to low-migration inks. The term low migration is rather used by ink manufacturers to identify UV inks that can comply with the regulations if used correctly on the relevant type of packaging. And the use of low-migration inks alone is far from sufficient to satisfy the regulations. The entire production process needs to be adapted. This starts with the sales department, which needs to know far more about the specific purpose of the label, and ends with the press, which must be adapted for low-migration production.

The impact of low-migration label production on a label print shop and the factors that need to be taken into account when switching to low-migration labels will be discussed in the second part of this series of articles in the next edition of Gallus in Touch.

Further information is available online at: