A study published online January 30, 2013 in the peer-reviewed scientific journal Food Chemistry finds that only nanomaterial fill percentage in the packaging material and storage duration influence nanosilver migration, but not temperature. The researchers from Ireland investigated how different fill content of nanosilver in the PVC material, storage duration and temperature influence the migration of nanosilver from polyvinyl chloride containers into chicken breast filet. The quantity of migrated nanosilver was equal with particles of 50nm and 10nm, suggesting that more of the smaller silver nanoparticles migrated. The silver measured in the food consisted of both ionic silver and particulate silver in nanosize, which is why it is not possible to draw any conclusion about how many more of the smaller particles migrated. So far, no specific migration limits for silver nanoparticles have been established in the EU.
Cushen, M., et al. (2013). "Migration and exposure assessment of silver from a PVC nanocomposite." Food Chemistry 139:389-397.