Migration is the central regulatory concern in food packaging inks and coatings. Uncured monomers, residual photoinitiators, solvents and additives can move through a packaging structure and into the food.
UV-curable systems attract particular scrutiny, because incomplete cure leaves free monomer and photoinitiator fragments that are exactly the kind of small, mobile molecules that migrate. The 2005 ITX incident, where a photoinitiator was found in packaged beverages, is why the industry treats this seriously.
Control comes from several directions: achieving complete cure, using higher-molecular-weight photoinitiators that cannot migrate easily, printing on the outer surface rather than the food-contact side, and relying on a functional barrier within the structure.
Compliance is assessed by migration testing on the finished packaging structure under defined conditions — never at resin level. A resin cannot be declared food-contact compliant in isolation.