How the migration of multiple compounds can be controlled below the threshold. Functional barriers and diffusion kinetics

The question of recyclability of food packages cannot be separated from the question whether a threshold-of-regulation concentration (TRC) can be established both from a toxicological as well as an analytical point of view. Such a threshold must be related not only to known but also and much more to unknown compounds. This requirement represents a considerable challenge to all parties concerned: the legislator, the food packaging industry and last but probably to the highest degree the enforcement laboratory. Protective use of functional barrier (FB) layers is currently the most applicable solution to this problem. Although from an R&D point of view a test approach using surrogate-spiked test samples is feasible and useful, it is evident that at this moment generally agreed or standardized test procedures are far from being available to the parties mentioned above. As a consequence individual test procedures are to be established case-by-case. In the last few years, the FhILV has under taken considerable research efforts to develop practical test strategies and evaluation procedures, also including migration theory and predictive migration modelling. From the results and experience collected so far it is concluded that by application of a suitable combination of test procedures and conditions the problem of FB efficiency testing and TRC control can be solved for any type food packaging.