Life cycle impact of nanosilver polymer-food storage containers as a case study informed by literature review†
Four hundred tons of silver nanoparticles are produced annually on a global scale. More than 25% of the consumer products that contain nanomaterials claim to have nano-scale silver (nAg), making it common in nanoenabled products, with food storage containers as one application. The antimicrobial property of nAg in these products helps to prolong the freshness of the stored food, thus potentially reducing food waste. Studies have found the migration of nAg from polymer nanocomposite food storage containers into the stored food to occur, which represents a concern to both the environment and public health. In this work, a midpoint life cycle assessment (LCA) is utilized in a cradle to grave capacity to compare the environmental and human health impacts of nAg enabled polymer food storage containers (at two different nAg concentrations) with their conventional counterpart. The electricity usage during the washing phase of a single nAg container represents the highest impact in almost all the ten categories due to the associated fossil fuel usage, while the impact related to the nAg leaching from this phase is insignificant in any scenario. This study demonstrates an increase in the overall environmental impact related to the integration of nAg on food storage containers compared to conventional food storage containers, however it was found to be very small (less than 1.6% of the total environmental impact). This work suggests that the environmental impact of nAg enabling food storage containers is fairly small, which may have implications for future food storage applications.