Nanosilver Migrated into Food-Simulating Solutions from Commercially Available Food Fresh Containers

Manufacturers of food fresh containers use nanosilver as an antimicrobial agent, but the safe impacts of nanosilver release from commercial products are unknown. The nanoparticles that migrate from the consumer products should be determined to assess the safety and/or risks of nanotechnology. This paper describes experimental work carried out on one kind of commercial food fresh container (polyethylene plastic bags). In the experiments, the range of temperatures was from room temperature (about 25 degrees C) to 50 degrees C, the range of time intervals was from 3 to 15 days, and the bags were filled with four kinds of food-simulating solutions representing water, acid, alcohol and fatty foods, respectively. Microwave digestion method was used for sample pre-treatment. The scanning electron microscopy and energy-dispersive X-ray (SEM/EDX) analysis was used to confirm the presence and morphology of nanosilver additives, and the atomic absorption spectroscopy (AAS) analysis was applied, showing that the commercial bags contained 100 mu g (Ag)/g (plastic materials). Strong evidences from SEM/EDX and AAS analyses were found, indicating the migration of nanosilver from the polyethylene bags into food-simulating solutions. The amount of nanosilver migration was observed as increasing with storage time and temperature. Copyright (C) 2011 John Wiley & Sons, Ltd.