Mathematical modelling of migration: a suitable tool for the enforcement authorities?

A few years ago, it became accepted that the plastics industry could use migration modelling for compliance testing. When a calculation confirms that the migration of a compound from a plastic material or article is below the specific migration limit, this is considered sufficient documentation for compliance with legislation. In the case of non-compliance, the result needs to be verified experimentally. The European Commission recommends that the enforcement authorities use migration modelling as well to avoid long and expensive analysis. The aim of the present work was to investigate the practical possibilities of implementing migration-modelling software as a tool in official food control and possibly in improving the own-check programmes of Danish plastic-converting plants. Food inspectors from nine regional food control centres initially attended a training course in the use of a commercial modelling software package and were supported further during the project period of about 1 year. They visited 40 producers of final plastic materials and articles, but mainly due to a lack of elementary knowledge of the detailed composition of the materials only 16 full migration calculations were performed. A major reason was a lack of information from those in the raw material supply chain who considered their products protected by commercial confidentiality. In general, the food inspectors were in favour of using migration modelling for future control visits.