Roland Franz, senior researcher at the Fraunhofer Institute, Freising, Germany, presented his research on the migration of titanium dioxide and silver nanoparticles from plastic food packaging into food on March 26, 2013 in Brussels. The lunch-meeting was organized by PlasticsEurope and was attended by an audience from both industry and the political realm. Franz and his team investigated the migration of nanoparticles from Low Density Polyethylene (LDPE) into different food simulants. No significant increase in nanoparticle levels in the simulant in comparison to the controls was observed. Only for the migration of nanosilver into acetic acid increased levels were reported, but the silver was identified to be ionic silver.
It is not clear how the toxicity of ionic silver and silver nanoparticles differs. The toxicity of nanosilver is thought to arise from the presence of ionic silver (Xiu et al. 2012). Ionic silver may be present in nanoparticles either as an impurity or because its nanoparticles oxidize into ionic silver. Silver ions are toxic to bacteria and algae. The full study will bepresented at the American Chemical Society (ACS) Spring Meeting 2013, taking place April 7- 11 in New Orleans, U.S..
Xiu, Z.-M., et al. (2012). "Negligible particle-specific antibacterial activity of silver nanoparticles." Nano Letters 12:4271-4275.