Caps and closures are a very large and complex segment of the food packaging market: they must have physical and mechanical properties that prevent organic contamination and organoleptic food alteration, as well as ensure an easy opening of the container.
However, the most crucial issue with regard to materials in contact with food is that even caps, closures and closing elements (rubber seals) are a potential source of contaminants.
The ability to come into contact with food depends on their specific use: compliance can only be positive if the contribution to the migration of contaminants both by the cap and its container can be calculated.
Caps manufacturers not always are in the condition to know which container or bottle will be associated to their product.
In the case of plastic caps, EU Regulation no. 10/2011 establishes different units of measurement to express the results of migration tests (art. 17), depending on whether the information on the container.
If the final use is:
- known, overall migration is expressed in mg/dm2 and specific migration in mg/kg;
- unknown, overall and specific migration is expressed in mg/article.
Overall migration is a measurement of material inertia, while specific migration refers to the maximum quantity of a given substance that can be transferred from packing to the food.
Mérieux NutriSciences verifies food compliance requirements on caps and closures and performs overall and specific migration tests.
Moreover, even in the case of missing data on the container -a difficult situation to manage for a manufacturer who wants to check the conformity of its articles-, our Food Contact Experts team is ready to offer its support to correctly understand the analytical data.
This approach applies to small caps with limited contact surface. For caps and closures whose surface is as large as the container, the result is expressed in mg/dm2 or mg/kg as the contribution to migration is comparable to that of the container itself.
