Migration and exposure assessment of silver from a PVC nanocomposite

Nanotechnology is the manipulation of matter at the nanoscale, generally between 1 and 100 nm. The discovery of unique nanomaterial properties has lead to novel applications in the food industry, one of which is antimicrobial food packaging materials. The objective of this study was to evaluate the migration of silver from plasticised polyvinyl chloride (PVC) nanocomposites to chicken meat following varying storage time and temperature conditions. The silver content of the chicken was quantified using inductively coupled plasma mass spectroscopy (ICPMS) and migration was found to occur within a range of 0.03-8.4 mg/kg. An exposure assessment revealed that human exposure to silver (assuming a worst case scenario that all silver is in its most harmful nanoform), is likely to be below current migration limits for conventional migrants and a provisional toxicity limit; however it is acknowledged there is still considerable uncertainty about the potential harmful effects of particles at the nanoscale. A sensitivity analysis revealed that silver migration from the nanocomposite to the food surface was influenced most by the percentage fill (p<0.01), followed by storage time (p<0.01) and storage temperature (p<0.05). This study represents an initial and much needed attempt to quantify human risks from the use of nanomaterials in the food industry.