Fraunhofer expert: nanoparticles don't migrate from food plastics
Dr Roland Franz, coordinator of the Fraunhofer Institute's department for process engineering and packaging, delivered his verdict at a lunch debate at the European Parliament on March 26.
Franz was addressing the question: can nanoparticles migrate from food contact plastics into foods? He used the European Commission's recommendation of nanoparticles under 2011/696/EU.
His presentation was based on research conducted as part of the Bavarian Authority for Public Health and Food Safety project on Nanotechnology-related Food Safety.
He said migration studies showed no evidence that nanoparticles of silver and titanium nitride with spheric shape incorporated at various levels into low density polyethylene (LDPE) migrated into food simulants even under severe test conditions.
Highest mobility
Spherical nanoparticles were analysed because they are believed to have the highest mobility and LDPE was used because it is thought to allow for the highest mobility of migrants, he said.
Nanoparticles of titanium nitride are used in polyethylene terephthalate (PET) bottles for water and soft drinks.
The European Food Safety Authority had also given its opinion that such an application involved no consumer exposure to nanoparticles, said Franz.
Franz added that particles measuring three to four nanometres in diameter "cannot migrate at all from LDPE
and therefore from any plastics food contact material (FCM) following Fick‘ian law of diffusion".
Aggregation and agglomeration
In any case, due to aggregation and agglomeration, nanoparticles of such a small size did not exist in FCM, he said.
Furthermore, even accounting for the worst case scenarios, he said the assumption was that nanoparticles were immobile once incorporated into FCM plastics.
"Concerns have been expressed whether release of nanoparticles from the food contact material surface due to mechanical material stress or due to aggressive interactions of the food with the FCM may be possible," he continued.
"In this case the FCM would be technically not fit for purpose. This can be checked by electron microscopic imaging of the FCM surface or stress tests using an appropriate liquid contact medium."
