Consumer Behavior and Compostable Packaging: Is Compostable Packaging Always Worth It? 

By: Elinor Arndt, Monica Rodriguez, Jordan Sachs

Welcome!

To start things off, please fill in the following "quiz," don't worry about if you get it right or wrong, go with your gut feeling  (Quiz: How Would You Dispose of This? ) Here we would like to set the stage and explore your thought process to see in which bin, in an ideal world, you would dispose of packaging. Keep this in mind as we then talk about real-world scenarios and how in many cases, ultimate disposal is not up to you or the manufacturer of the material. 

Scenario 

Our role is that of “human behavior researchers” who look at how people dispose of different types of compostable food packaging. Our goal is twofold. For our first audience, the general public, we would like to ultimately conclude if there is one packaging type that people dispose correctly at a higher rate. And for our second audience, if there are differences in the disposal, we would recommend to the food retailers who make purchasing decisions if one packaging type is ultimately worth more than the other since compostable packaging tends to be more expensive. 

Abstract

This paper provides an overview of compostable and biodegradable packaging in food production systems. The purpose of this study is to explore the relationship among producers, consumers, and food packaging. The authors of this paper used outside sources to decide to answer the question of: is compostable packaging worth it in food production systems/restaurants? There is a case study included on two restaurants in very different areas of the country: Madison, WI and Fort Myers, FL. The authors use this authentic data to understand the packaging dynamics in small take-out restaurants.

Introduction

Waste from packaging has been a frequently mentioned waste category that can be reduced to alleviate the burden of waste worldwide. Packaging alternatives such as compostable packaging and bioplastics are currently in use in some locations as packaging. There are however, concerns of “greenwashing” and if these materials are truly better alternatives to petrochemically sourced plastic packaging. Reasons that these materials may not be better could be that their environmental costs stemming from manufacturing processes, and/or true consumer use and/or real end disposal options are higher than conventional packaging environmental impacts. In this paper the true consumer use and real end of life disposal are explored, and recommendations based on these findings are made.

The purpose of this study is to analyze the literature that has been published on consumer behavior with compostable packaging products. This is important since cradle to grave life cycle assessments (LCAs) consider the use phase, however, this is currently an under researched area and many of the use phase scenarios considered in LCA come from stylized scenarios using broad generalizations as a basis. Two case studies will be presented that will show how a nuanced localized analysis may lead to selecting a packaging material based on local, real world conditions.

Research Questions: 

1. Should food retailers purchase and offer compostable packaging? If so, which type? What considerations need to be taken into account?
2. What is the public's knowledge on compostable packaging? What is the public’s preference on compostable packaging? 

Terminology

Compostable Packaging- This is packaging that can degrade in composting conditions. Not all compostable packaging degrades in a regular compost. Some types only degrade in industrial composting locations where conditions are very controlled. Biodegradable and compostable packaging are a little bit different. Biodegradable packaging is packaging that can be broken down in natural conditions and will decompose on its own. Biodegradable packaging is made out of biopolymers from renewable resources that can be broken down in natural conditions. Compostable packaging is broken down in natural conditions, and also succeeds in providing the Earth with nutrients after it has been fully broken down. Composting is a type of biodegradation process.

Biodegradable Plastic Packaging- The three most commonly used bio-based plastics in food packaging are polylactic acid (PLA), starch-based plastics, and cellophane. These types of packaging are an option for consumers, however it is very difficult to tell the difference between biodegradable plastics and ones that are made from fossils. Because of this, consumers often do not know if they are using biodegradable packing or fossil-based packaging. This leads them to dispose of it in the wrong place. This type of packaging is also more expensive than fossil-based packaging, making it less desirable for owners of stores and restaurants in that sense. Bio-based plastics can be composted in homes and industrial settings. Bio-based plastics that do not end up getting composted or biodegraded will end up in landfills and will eventually be destroyed by burning.

Starch-based Compostable Packaging- This is a different type of packaging that is made from starch-based polymers. Starch is a natural polymer that is often used in biodegradable materials because it is easily broken down, and it is very abundant in the environment. These polymers are typically taken from grains like corn, wheat, and potato. Forage Kitchen, which is part of our case study, uses PrimeWare for their food packaging. This company produces compostable products, and Forage Kitchen uses their starch-based bowls and utensils.

Methods

A literature survey was conducted. The objective of this review is to analyze the current body of LCA literature that compares compostable packaging with conventional packaging, and literature that discusses human behavior and compostable packaging. There is a particular focus on the end of life (EOL) of these compostable packaging types and the role of human behavior in that EOL. The review was conducted by searching in the following databases on Google Scholar. Search was limited to research published on or after 2015. Keyword searches include: compostable food packaging, “consumer or human” behavior and compostable food packaging, “consumer or human” behavior and compostable packaging, “consumer or human” behavior and packaging disposal, and knowledge of compostable packaging. For the case study locations were selected due to different climates, different locations within the contiguous United States and different demographics as Madison, WI is more a college town versus Fort Myers, FL which is more a retirement community. The authors are familiar with these locations and finding information for these was convenient.

Literature Review

A Life Cycle Assessment (LCA) is a tool used to determine the environmental impacts of a product or system. It uses the inputs of acquiring raw material, production, transportation, use phase, and disposal and determines the outputs for the environmental impact categories considered in the study, which depends on the method used in the LCA. For example, TRACI is used in the US which provides characterization factors for 10 environmental impact categories. These include eutrophication, acidification, ozone depletion, global warming, smog formation, ecotoxicity, human health impacts, and fossil fuel depletion. Researchers develop characterization factors that associate and connect activities related to the product or service to inputs that are then used to calculate the output which are the impact categories.

Gutowski (2018) argues that humans who are the ones who actually use the products or the services are not centered in LCA but that the product itself is. This is problematic because the environmental impacts may be highly dependent on the use phase and the end of life choice made by the user.
Informing people of the waste they generate is not sufficient to motivate people into sustainable waste sorting behaviors. (Minelgaite and Liobikiene, 2019) Furthermore, it was found that consumers do not effectively sort recyclables and nonrecyclables. (Hsieh et al, 2019) Complicating the picture is adding compostable packaging alongside recyclable and non recyclable. People may not be able to tell the difference between the packaging types as it is difficult to even distinguish between the recyclables and nonrecyclables. 

When comparing PLA with PET, PLA is worse in four categories as observed in Figure 1. This study by Moretti et al., however, considers a general waste management treatment scenario that does not take into consideration the nuances of a location. As observed in Table 1, landfill is not necessarily the worst across all impact categories but in climate change and ozone depletion in the Moretti et al study, it has the highest impact when compared with other waste disposal options. Hottle et al. (2017) compared PLA and PET with different disposal options. In Figure 2, it is evident that landfilling PLA has higher environmental impacts than recycling and landfilling PET.

Figure 1: This figure shows how different plastic materials (PLA, PP, and PET) affect the cradle to grave percent contribution for each environmental impact. (Moretti et al., 2021) 

 

Table 1: This table shows the impacts of each end-of-life option presented, these include only the impacts arising from EoL, as it is assumed that since it is the same PLA cup, these are the same from other stages in the life cycle. (Moretti et al., 2021)

Figure 2: This figure shows the climate change impact according to material and corresponding disposal scenario. (Hottle et al., 2017)

 

Case Study 

Forage Kitchen is a local restaurant in Madison, Wisconsin with three locations. It is known for their healthy salads and grain bowls. All the ingredients they use are sourced from local and organic farms or Co-ops, and they prepare the ingredients in the restaurant each day. We contacted the restaurant to inquire about their packaging. The employee reported that the bowls they use for to-go food are the brand Prime Ware. This packaging is compostable and made from sugar cane molded fiber. It is also microwave and freezer safe. While on the phone, the employee seemed knowledgeable and informed about their packaging offering and disposal. Forage is located in Madison, WI. The population of Madison, Wisconsin is 259,673 people. The average per capita income is $40,834, and 14.7% of the population lives below the poverty line. 73% of the population is white, 7% is black, and 9% is Asian.

Bahia Bowls is an acai bowl and salad restaurant in Fort Myers, Florida. On their website, they do not mention anything about their ingredients being from local farms. They claim their ingredients are organic. Our goal is to contrast similar types of restaurants in two different areas. When we contacted Bahia Bowls, the employee was not as knowledgeable about their packaging offerings. She reported that the packaging was compostable, but the only knowledge she had about it was that they use paper bags and plastic bowls. When we tried to confirm that the plastic bowls are compostable, she was not fully certain. We therefore assumed that the packaging was either PLA or PLA coated given the mention of plastic compostable bowls. Bahia Bowls is located in Fort Myers, FL. The population of Fort Myers, Florida is 96,851. The average per capita income is $29,991, and 16.8% percent of the population lives below the poverty line. 64% of the population is white, 22% is black, 2.76% is Asian.

Map from Google Images, location images from Dane County Solid Waste Management Authority, vignette by Rodriguez Morris (2019).

 

Results

Given the information you've seen and how the benefit of employing compostable materials depends on the waste treatment alternatives available, we would like to now walk you through how you would decide how to dispose of a PLA cup in Madison, WI in the following activity. This is part of our Madison, WI case study.

As observed in the activity for our Madison, WI case study, PLA cups are not currently accepted in compost facilities and although this material is recyclable, recycling in the US is not widespread. Therefore, in Madison, PLA cups end up in the landfill. Even if a person incorrectly sorts it into the compost or recycling bin, they will be picked from the waste stream that is received and sent to the landfill. If this PLA cup is deposited knowingly into the compost or recycling bin, this is known as wishful recycling. In the end this incorrect sorting has detrimental effects to the facilities and actually increases the environmental footprint of the cup due to unnecessary transportation. 

In 2018, PET recycling, which is a material used for beverage and bottle cups, was around 30% (EPA). This number has since probably decreased due to material import restrictions in countries the US historically sent their recovered plastic bales. We estimated that this could then be reduced to around 20% recycling. Using the data from the cradle-to-grave analysis conducted by Hottle et al in 2017, we analyzed the environmental impact of a PLA cup versus a PET cup in Madison, WI and included their current, real-world, end of life waste management treatment. As observed in Figure 3, PLA at 100% landfilling has lower environmental impacts in Ozone Depletion, Carcinogens, Non-Carcinogens, Respiratory Effects, Ecotoxicity, and Fossil Fuel Depletion. However, in the Global Warming, Smog, Acidification, and Eutrophication. Considering that eutrophication is of concern in Madison due to impairment of water bodies surrounding the Madison area, this impact category should be given more weight than others. In addition, global warming is an important indicator that in many instances is considered the benchmark for comparing products and processes. Given that these two categories, eutrophication and global warming, are higher when PLA is 100% landfilled versus PET that is 70-80% landfilled and 20-30% recycled, we recommend that PLA cups not be offered in Madison restaurants and stores.

Figure 3: Environmental Impacts for Complete Life Cycle According to EoL (Hottle et al., 2017)

According to Fangmongkol and Gheewala (2020), polystyrene performed better than bagasse (sugar cane) based compostable tableware, like that used in Forage, in many categories. In the case of global warming potential, as observed in Figure 4, all bagasse scenarios had higher environmental impacts than all PS disposal scenarios. In the case of freshwater eutrophication, bagasse packaging outperformed PS only when it is recycled. Which recycling is not an option for compostable packaging in Madison.  The environmental performance of both types of packaging (PS and Bagasse) depended on the disposal method. In the case of this type of tableware, sugar cane based packaging, it is much more likely to be put into compost bins correctly and accepted in facilities than PLA. There will still be however a percentage that ends up in the landfill. 

Figure 4 Environmental Impact of Packaging for Food Made form Polystyrene (PS) and From Bagasse like the one used in Forage (Fangmongkol and Gheewala, 2020)

 

We did not receive information for waste management in Fort Myers, FL. However, from what we did find, it seems likely that PLA management is identical to that in Madison, WI. In the case of the compostable packaging for food, the person we contacted mentioned plastic bowls that are compostable, we suspect these are made from PLA or PLA coated. If this is the case, it is less likely that these are composted when compared with sugar cane based packaging. Therefore, our Madison, WI recommendation stands, that PLA packaging is not recommended due to its current waste management.

Conclusion/Limitations

Waste management infrastructure varies greatly nationally, regionally and locally. Making a blanket statement as to what type of compostable packaging is recommended is not a viable option. Therefore focusing on two locations and presenting them as case studies was presented.

Overall, consumers are ineffective waste sorters. Although consumer waste education initiatives inform the consumer, ultimately consumers may not end up changing their disposal behaviors. People are often forgotten in LCA studies. A product’s positive points ultimately rely on how people use them, as they are the ones who the product is actually made for. The package is made for human use, not the other way around. Based on current waste management alternatives for PLA and sugar cane packaging, we recommend that PLA packaging not be offered in Madison, WI locations. For sugar cane packaging it is more difficult to decide, however this type of packaging isn’t perfect and not necessarily better. As use of these materials becomes more widespread and technology to treat these waste streams develops, these recommendations should be revisited. 

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About the Authors

Elinor Arndt is an undergraduate senior at UW-Madison. She is majoring in Animal Science and plans to attend veterinary school next year.

Mònica Rodrìguez Morris is a graduate student in the UW Madison Civil and Environmental Engineering Department. She is from San Juan, Puerto Rico and is a self proclaimed garbologist.

Jordan Sachs is a senior at UW-Madison majoring in Animal Science. She plans to move to London, UK in the fall to start pursuing her DVM degree at the Royal Veterinary College.