When we cannot see everything, we see nothing
In the case of beer cans, replacing the plastic secondary packaging with cardboard packaging has no environmental benefits.
What Carrefour and Heineken claim to be good environmental practice is in fact a bad idea: this decision by the Heineken brand will result in a very significant increase in the environmental impact of this secondary packaging, which moreover only represents about 5% of the total impact of this beer pack... The reason for this is that more cardboard is needed to pack six cans than the original plastic. The real ecological transition is too serious a cause to risk false good ideas.
The conclusions of Glimpact's analysis, carried out according to the PEF method (adopted by the EC), are based on data from are presentative sample of commonly observed products. Therefore, they do not take into account the specificities of production conditions or means of production.
The results below show that for all scenarios, using plastic secondary packaging has a 2 to 12 times lower impact than using cardboard packaging.
Seven scenarios were considered in this study: three plastic packaging scenarios and four cardboard packaging scenarios, in order to include packaging with recycled content (RC). To pack six aluminium cans, more cardboard is needed in weight (23.1g considered on average in this example) than plastic (6.2g on average).
The analysis follows the methodological rules of the PEF (Product Environmental Footprint) method:
- The entire life cycle of the packaging is taken into account, i.e.: the production of the raw materials (plastic granules or paper pulp, virgin or recycled), the production of the packaging (extrusion of the plastic film or production and cutting of the cardboard), the printing and finishing, the distribution and the end of life of the packaging.
- The result is the aggregation of the 16 impact categories of the PEF method after the normalisation and weighting of these categories (PEF score expressed here in µpts). The higher the score, the greater the impact of the packaging. Thus, all the impact categories defined by the method are integrated, in particular land use, water resource consumption, fossil resource consumption, climate change, etc.
- The methodological rules of the PEFCR Intermediate paper have been followed to calculate the impact related to the production of the board
- The rules of the Circular Footprint Formula (CFF), recommended by the PEF method, are considered for the end-of-life of materials: recycling, incineration and landfill of packaging are integrated. In particular, the recycling/ incineration/ landfill rates are material and country specific. In the European end-of-life scenario considered here, the recycling rate for cardboard is 75% and the incineration rate is 11%, while for plastics the factors are 29% (recycling) and 32% (incineration) respectively, with the remainder being landfilled.
- The database used is the one made available by the European Commission (LCDN = Life Cycle Data Network nodes)
The plastic packaging considered in this study is a blend of LDPE (Low DensityPolyethylene), HDPE (High Density Polyethylene) and LLDPE (Linear Low Density Polyethylene) pellets, with 0, 50 or 100% recycled content. In scenario 1, a mixture of LDPE, LLDPE and ink is considered. In scenario 2, a mixture of LDPE, recycled LDPE, HDPE, LLDPE and ink is considered. In scenario 3, a mixture of recycled LDPE, HDPE, LLDPE and ink is considered. The extrusion, printing and finishing steps are considered.
The production of cardboard packaging includes the steps of pulp production, pulp transport, cardboard production and cardboard box production. In the initial scenario, 60% of the pulp is considered bleached hardwood kraft and 40% bleached softwood kraft. The data for the production of the board is taken from a study by KCL (The Finnish Pulp and Paper Research Institute). For box production, the activity data is taken from an average of six Swiss producers. In the minimum scenario, the pulp is 100% recycled and green energy is considered in the board production plant. In the maximum scenario, the pulp is produced in North America and the consumption in the mills is slightly increased.
The assumptions for the distribution scenario, between the packaging production plant and the packaging user, are identical for plastic and for cardboard: the PEF intra-continental scenario (130km by truck, 240km by train and 270km by ship). A European end-of-life of the packaging is considered in both cases, with the parameters of the Circular Footprint Formula (CFF) as specified above.
If we compare the impact of one kilogram of material, plastic is sometimes more impactful than cardboard, depending on the scenario considered. For example, cardboard in the initial European scenario has an overall environmental impact of 190 µpts/kg. Plastic film printed with 0% recycled material has an impact of 255 µpts/kg. However, when we consider the packaging function of the six cans, it is preferable to choose the plastic film, which has an environmental impact of (6.2g/packaging/1000) x 255 µpts/kg = 1.6 µpts/packaging, rather than the cardboard which has an environmental impact of (23.1g/packaging/1000) x 190 µpts/kg = 4.4 µpts/packaging.
These conclusions remain the same when the results are viewed under the climate change impact.
Thus, switching to cardboard does not reduce the environmental impact of secondary packaging, but rather increases it, particularly as more material is used. Furthermore, the environmental impact of secondary packaging contributes less than 5% of the footprint of a Heineken product.
The results were related to the secondary packaging function of six beer cans. This is the so-called functional unit for impact assessment.
