A Life Cycle Assessment of Plastic vs Cardboard Packaging in the Fast-Moving Consumer Goods Market

Abstract

Globally there is a movement to mitigate the need for single-use plastics as well as the utilization of plastic materials when alternative options are available. This movement comes in response to the extensive research that has demonstrated the long-term negative environmental impact that plastics pose to our existence when disposed of into landfills. A significant contributing factor to the mass of single-use plastics is the packaging industry. This study focused more specifically on the single use plastic packaging in the fast-moving consumer goods (FMCG) market which are used to shrink-wrap bottles together to be supplied into the trade such as Pick ‘n Pay and Checkers. South Africa is facing two main challenges pertaining to the FMCG market: namely the constrained supply of energy and the socio-economic pressure to reduce the environmental impact caused by unrecycled packaging waste. This research aimed to investigate the energy requirements and environmental impact of packaging configurations that included shrink-wrap plastic and cardboard cartons versus packaging configurations that utilized only cardboard cartons to ascertain which option provides the lowest possible energy requirements, and environmental impact. This study aimed to execute a cradle-to-grave life-cycle assessment (LCA) of the two different packaging configurations by utilizing the SimaPro software. The LCA was executed with respect to one reference product that is supplied into the FMCG market year-round known as Prewash Promo. Prewash Promo is a laundry pretreatment that aids in the removal of stains. The first of the two packaging configurations under analysis was the traditional packaging configuration of Prewash Promo that has always been used. This packaging configuration consisted of six bottles that were grouped into two sets of three using rubber bands. The two sets of three were then shrink-wrapped into a group of six. Two shrink-wrapped sixes were then placed into a box that was sealed using plastic packaging tape or sellotape. The second packaging configuration under analysis mitigated the use of shrink wrap plastic and associated materials (elastic bands) thus the second packaging configuration consisted of twelve bottles placed into the box that was then sealed using packaging tape. The main objective of this LCA was to ascertain the packaging material configuration that was the most energy-efficient and environmentally responsible choice to utilize in the Stephanie Anne Rivett A Life Cycle Assessment of Plastic vs Cardboard Packaging in the Fast-Moving Consumer Goods Market iv FMCG market. This LCA was conducted utilizing the data pertaining to the year 2022 and the functional unit of this study was one year’s worth of packaging used in the production of Prewash Promo. Prewash Promo was chosen as the reference product as it does not demonstrate seasonal or geographically specific use, and it was a viable option for the change in packaging configuration. A significant factor that influenced the impact of LCA results was the waste scenarios associated with the use of different materials. In this study, the exact quantities of material that were recycled versus sent to landfills could not be definitively known. It was for this reason that the published industry standard recycling rates for the year 2022 and knowledge of socioeconomic habits were used to formulate assumptions. It was assumed that the minor materials included in the packaging configurations such as packaging tape and elastic bands conformed with social habits and did not exhibit any recycling and went directly to landfill. The recycling rate of corrugated board for the year 2022 was reported to be 61.4% and the recycling rate of plastic for the year 2022 was reported to be 42.8% (Mpact Recycling, 2019a). These recycle rates were utilized to model the packaging configurations to facilitate the comparison between the two. The validity and influence of these assumptions were assessed by means of a sensitivity analysis after the main LCA was executed. The ecoinvent 3 database library available via the SimaPro software (version 9.4.0.3, 2022) and the ReCiPe Midpoint method were used to execute the impact assessment calculations. This method consisted of eighteen impact categories that assessed the impact of each of the packaging materials with respect to the impact they posed to human health, biodiversity, and resource scarcity. The full eighteen category impact assessment was condensed into five focus categories based on the target audience, the research objectives and geographical location of the study. These five focus categories were: global warming, stratospheric ozone depletion, fine particulate matter formation, freshwater ecotoxicity and water consumption. These five categories were chosen because they provide the best overview of the impact in a summarized form pertaining to factors contributing to environmental decline, changing weather conditions, reduction in air quality and the impact of freshwater resources. The LCA was first executed for each packaging configuration in isolation to ascertain the impact contributions of each of the individual factors involved in the construction of the Stephanie Anne Rivett A Life Cycle Assessment of Plastic vs Cardboard Packaging in the Fast-Moving Consumer Goods Market v packaging set-up. The analysis of each packaging configuration in isolation facilitated highlighting major contributing factors to consider replacing with alternatives or mitigating the use thereof. This assessment highlighted the drastic impact contribution that the use of electricity had on the impact score of the heat shrink-wrap plastic configuration. The full LCA comparison was then executed to compare the two packaging configurations. In each of the five focus impact categories the corrugated board only packaging configuration achieved an environmental impact score 83% lower than the heat shrink-wrap plastic packaging configuration. This drastic difference was only reduced to 79.6% when excluding long-term emissions. Upon the conclusion of the LCA comparative assessment the validity of the recycle rate assumptions for corrugated board and shrink-wrap plastic were assessed by executing sensitivity analyses. These analyses determined that the conclusion achieved at the end of the LCA comparison stage remained valid irrespective of the recycling rate of corrugated board or shrink-wrap plastic. The final objective investigated in this study was the uncertainty analysis to assess the accuracy and reliability of the data utilized in the LCA. The uncertainty analysis was executed in the SimaPro software by utilizing a Monté Carlo analysis with the ReCiPe 2016 midpoint (H) method which consisted of 1 000 fixed runs with a confidence interval of 95%. An uncertainty bar chart was generated that displays the error associated with each of the eighteen impact categories. The uncertainty analyses for both packaging configurations determined that the data for global warming, stratospheric ozone depletion, fine particulate matter formation and freshwater ecotoxicity demonstrated low error. The cardboard only configuration exhibited very low error values of between 8% and 61% as opposed to the plastic packaging configuration which exhibited errors between 16% and 214%. The water consumption data in contrast exhibited significant uncertainty for both configurations due to the difficulty in definitively determining accurate water consumption data for such extensive life cycles. Water was utilized extensively in the developmental stages of each of the materials (forestry, paper/pulp manufacturing and plastic polymer and plastic shrink manufacturing) and exhibited significant variation in volume of consumption due to high degrees of variation in plant technology and process equipment age. Stephanie Anne Rivett A Life Cycle Assessment of Plastic vs Cardboard Packaging in the Fast-Moving Consumer Goods Market vi The culmination of the results of each of the assessments executed concluded that the corrugated board only configuration is the packaging configuration that is the most environmentally friendly, and energy-efficient packaging option of the two that were considered.