Environmental assessment of chitosan-based films

A comparative environmental assessment between two different food packaging systems was carried out: a commercial food packaging film based on polypropylene (PP) and a new biodegradable chitosan-based film developed in our labs. The environmental load of chitosan-based films in different life cycle stages was studied and compared with the one of conventional PP films currently used as food packaging. The functional unit in this study was 1 m2 of packaging film. The studied system includes three main stages: material extraction, film manufacture, and end of life. Results showed that PP films have higher impact than chitosan-based films in carcinogens and in fossil fuels impact categories. The environmental burden associated to carcinogens is mainly due to the end of life stage, while the impact related to fossil fuels is owing to the extraction of PP. On the contrary, chitosan-based films have higher environmental load in respiratory inorganics, land use, and minerals categories. Environmental load associated to respiratory inorganics is mostly related to the acetic acid used in the film manufacture and, in a more significant way, to the hydrochloric acid used in the raw material extraction, which is also responsible for the impact in minerals category. In addition, the main responsible for the impact in land use category is glycerine, considered as a by-product from biodiesel, used in the film manufacture stage.