Research

Exposure to chemicals in food packaging as a sustainability trade-off in LCA

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Abstract

Hazardous chemicals in packaging, including ‘eco-friendly’ and recycled food packaging, can migrate into food and expose humans. LCA has been fundamental to indicate more ‘eco-friendly’ packages, but currently LCA does not consider exposure to chemical migrants and methods have not yet been developed. In this study we question if exposure to chemicals in food packaging should be considered as a sustainable design consideration, i.e. if this human health risk is relevant in a life cycle context. To answer this question, we focus on developing methods to quantify exposure to chemicals in food packaging in a life cycle impact assessment (LCIA) framework. To put exposure during use in a life cycle context we perform a screening-level LCA of several life cycle stages of high impact polystyrene packaging (HIPS), with a functional unit of containing and delivering one kilogram of yogurt for consumption. For screening, we include exposure via environmental emissions from the production of the raw material HIPS, thermoforming into packaging, 14 day refrigeration by consumers, and disposal via incineration. The purpose of this screening is not to obtain a detailed and accurate LCA of HIPS but to provide life cycle context to compare the magnitude of characterized exposure to chemicals in packaging, in order to elucidate if this exposure pathway is important. We detail estimates of life cycle exposure to one known hazardous chemical in polystyrene packaging (styrene) that has data available on concentrations in yogurt packaged in HIPS and life cycle inventory releases. We also extend this analysis, given data limitations, to include exposure to three other chemicals in HIPS packaging through food. Given that data on concentrations of food packaging chemicals in food are often missing, we also explore methods to model the product intake fraction (PiF) as the fraction of chemical mass taken in through food packaging versus its initial mass in the food packaging. Results demonstrated that in the given cases consumer exposure to chemicals in packaging through consuming packaged food can be greater than population-level exposure mediated by the life cycle releases of such chemicals, even when only considering one or several chemicals in packaging that expose consumers. Occupational exposure was not consid ered in this study, but could be a focus of future work. Thus, this initial exploration indicates that exposure to chemicals in food packaging can be an essential consideration for burden shifting and quantifying design trade-offs in a life cycle context.