Reusable plastic boxes generate less environmental impact than single-use cardboard boxes

Reusable plastic boxes generate 25% less environmental impact than single-use cardboard boxes in the distribution of fruits and vegetables in Spain. This is true in five of the six environmental impact categories analyzed by the comparative study of the different distribution options for fruit and vegetables in Spain, according to the Life Cycle Analysis (LCA) carried out by the UNESCO's Life Cycle and Climate Change studies (ESCI-UPF), directed by Professor Pere Fullana.

The goal of this study, promoted by the Association of Logistics Operators of Reusable Eco-sustainable Elements (ARECO), has been to obtain objective and scientifically based information on the environmental impact associated with the distribution of fruits and vegetables in the Spanish (Peninsular) domestic market, by comparing two packaging solutions: single use cardboard boxes and reusable plastic boxes.

To do this, researchers used the Life Cycle Analysis (LCA) methodology, which allows analyzing the environmental impact associated with all stages of the boxes lifespan, from the extraction of raw materials for their manufacture until they become a waste.

This study supposes an in-depth review of the existing studies, an adaptation to the Spanish reality, and an update of the study developed by the University of Stuttgart for the German foundation Stiftung Initiative Mehrweg (SIM) in 2009. The study was later reviewed by a panel of independent experts from the University of Cantabria, the Spanish Association for Standardization and Certification (AENOR), and the Center for Energy, Environmental and Technological Research (CIEMAT).

Systems analyzed

The study compared single-use cardboard boxes, which are 80% recycled [i], with reusable plastic boxes that use reverse logistics, wash containers and that are 100% recycled at the end of their useful life.

The study analyzes two possible scenarios, based on reality, in relation to the useful life of reusable plastic boxes:

Conservative scenario (base): a useful life of 10 years, 10 rotations per year

Technical scenario: a useful life of 15 years, 10 rotations per year

The functional unit used for the analysis, which allows comparing the two systems, is "the distribution of 1,000 tons of fruits and vegetables in (single use) cardboard boxes or (reusable) plastic boxes." To translate this functional unit into reference flows, that is, the number of plastic and cardboard boxes required, researchers took into account that each box can transport 15 kg of product. This means that 66,667 boxes are needed to transport those 1,000 tons. In the conservative scenario, plastic boxes have a 10-year life and make 10 rotations a year. This means that during their 10-year life, the plastic boxes can be filled 6,666,700 times.

Life cycle analysis

The study includes the complete life cycle of the two distribution systems, taking into consideration their different stages: extraction of raw materials to manufacture the boxes, production process, distribution and use, and recycling or final disposal in a landfill or an incinerator once their useful life has ended. Auxiliary systems, such as transport of raw materials for the manufacture of boxes, the obtaining of electrical energy from primary energy sources, and that of waste, are also included in the analysis.

The categories of environmental impact analyzed were:

Use of primary energy (renewable) (EP-R);

Use of primary energy (non-renewable) (EP-NR)

Global Warming Potential (GWP)

Potential for Destruction of the Ozone Layer (PDCO)

Acidification Potential (PA)

Eutrophication Potential (PE)

Potential for Formation of Photochemical Oxidants (PFOF)

Results

Reusable plastic boxes had a better environmental performance than cardboard boxes in all categories analyzed. Researchers observed that the consumption of primary energy from renewable and non-renewable sources is lower in the case of plastic boxes, which is closely associated with a lower consumption of materials of renewable and non-renewable origins in plastic boxes.

If the difference between single-use cardboard boxes and reusable plastic boxes is scaled from the functional unit applied to the total number of boxes mobilized for organized distribution in Spain during one year (approximately 550 million fillings), the impact on the most influential category, the Global Warming Potential (GWP), would imply an annual saving of 785,239,967 kg of CO2 (taking into account the conservative scenario of 10 reuses per year). This represents 0.24% of the direct emissions generated by Spain in one year.

In the study, a sensitivity analysis was carried out to determine the robustness of the results and to see if some of the variables might or might not modify the trend in the results obtained.

Conclusions

The results of the study clearly show that reusable plastic boxes have a better environmental performance than single-use cardboard boxes. Only the Acidification Potential (PA) of both types of boxes has a similar impact. Even after the sensitivity analysis, the reusable plastic boxes have a better environmental performance. The plastic boxes' environmental impact was always more than 25% less damaging than that of the cardboard boxes, except in their Acidification Potential, Eutrophication Potential and energy consumption in two cases.

[i] According to data from REPACAR (2014), Spain recycles approximately 80% of cardboard boxes each year. No specific data has been found on fruit and vegetable distribution boxes. Even though the percentage of recycling may be lower in this case, due to contamination by organic matter of the cardboard, the conservative scenario maintained the assumption that 80% of them were recycled.