Environmental Assessment of a multilayer polymer bag for food packaging and preservation: an LCA approach

A screening of LCA for the evaluation of the damage arising from the life cycle of a bi-layer film bag for food packaging was carried out. Such packages are made of films obtained matching a layer of PA (Polyamide) with one of LDPE (Low-Density Polyethylene) and are mainly used for vacuum or modified atmosphere packaging and preservation of food. The study was conducted in accordance with the ISO standards 14040:2006 and 14044:2006 choosing, as the functional unit, 1 m2 of plastic film delivered to the food production and packaging firms. The system boundaries go from cradle to factory-gate and include the phases of: the raw materials production and processing for the bag manufacturing; and the bag delivering to the food production and packaging plant. The damage assessment showed that the most impacting phases are the production of the Polyamide (PA6) and Low-Density Polyethylene (LDPE) granules due to the consumption of primary resources, such as natural gas and crude oil, in the amount of 53.55 dm3 and 132.42 g respectively, and to the emission in air of 295.73 g of carbon dioxide, 617 mg of nitrogen oxides, 12.1 mg of particulates, 349 mg of sulphur dioxide and 2.51 mg of aromatic hydrocarbons. The most affected damage category is Resources, followed by Climate Change, Human Health, and Ecosystem Quality. For minimising the total damage associated with the life cycle of the examined bag, the film thickness thinning and the use of a recycled PA granule were considered: the assessment showed that the two proposals allowed a reduction of about 25% and 15% (respectively) of the damage assessed.