Contact with food: conformity assessment - Part 2

Migration modeling is a rapid approach that has recently been introduced for demonstrating the conformity of food contact materials, health monitoring and the design of safe food packaging materials. In the previous dossier [AF 6 930] "Food contact: conformity assessment. Part 1", we studied the prioritization of contamination risks associated with different packaging components, material type and conditions of use (type of contact, temperature, etc.). The prototype physical model for a single-layer material in contact with a semi-solid food or food simulant is described. More sophisticated models for multi-layer materials, or taking into account the effects of uncertainty, are proposed in the dossier "Modeling the risk of contamination of packaged food" [AF 1 446] .

In particular, this dossier presents the molecular mechanisms and main physico-chemical properties that control the migration of substances from thermoplastic materials into foodstuffs: partition coefficients K, diffusion coefficients D and their activation parameters with temperature. The effects of molecular characteristics (size, polarity, bulk, symmetry, etc.) of contaminants on molecular properties are presented and discussed, with a view to developing predictive models or robust rules for extrapolating properties from existing data. As knowledge of molecular mechanisms is still being acquired, notably through molecular dynamics simulations, the models presented are regularly refined or extended. With this in mind, readers wishing to extend the models to cases that have not yet been studied (type of substance, polymer, etc.) are asked to take into account an appropriate margin of uncertainty, based in particular on the diversity of behaviors and the "safe" extrapolation rules presented in this dossier.