Plastics have transformed everyday life, with more than 400 million tonnes of plastic and plastic products being generated every year across the world. While plastics often bring many societal benefits and play an instrumental role in manufacturing, technology, healthcare etc. there are significant concerns regarding the quantities of plastic waste being discarded into the environment. In Canada, it is estimated that only 10% of all plastics produced in the country are actually recycled, with the balance accumulating as waste in landfills, public spaces, water ways and oceans. This accumulation of plastics entering into terrestrial and aquatic ecosystems poses acute risks to both human and animal health, with bio-accumulation of plastics being observed as causing endocrinlogical disruptions to wildlife. It is with this in mind that in January of 2020, the Canadian federal government announced a proposed ban on single use plastics items by the year 2021. This decision was informed by a report commissioned by Environment Canada concluding that single use plastics posed significant risk to the environment resulting from both their manufacturing and disposal.
While this decision has generally been met by a favorable response from both environmental groups and the public, there remain significant questions regarding what single use plastics will be banned. There remains considerable uncertainty regarding what the rationalization and methodology for evaluating which materials should be banned, in addition to the short and long term economic implications resulting from a single use plastics ban.
However, despite the findings of the Environment Canada report, and the prevailing negative sentiment surrounding plastics, and particularly plastic packaging, it is important to recognize that not all plastics are created equal. While the vast majority of plastics are made from ethylene derived from hydrocarbon sources, there exists a significant heterogeneity with respect to the types of resin (polyethylene, polypropylene, polystyrene etc.), including how it is made, how it is used, why it is used and what can be done with it at end of life.
Many of the environmental concerns attributable to plastics tend to be focused on the manufacturing stage and available end of life waste management options. It is during these two stages that the release of macro plastics (pieces larger than 5mm) and micro plastics (pieces smaller than 5mm) into the environment is considered highest.
While the Environment Canada report undertakes a comprehensive literature review to determine the risks posted to both human and ecological health attributable to plastics in our environment, it does not offer any guidance regarding which plastics to ban, or provide an evaluative framework that can assist decision makers in identifying problematic materials.
One of the dangers of characterizing all single use plastics the same way (bad for the environment, should be banned etc.), fails to capture the complexity and nuances of plastics, particularly for packaged goods.
This white paper outlines a potential evaluative framework for examining the environmental, economic and social impacts of plastic materials (with a specific emphasis on household plastic packaging). The purpose of this framework is to provide both policy makers and plastic producers with a decision making tool that captures the latest in life cycle thinking and consequential impacts (both economic and social), resulting from proposed material bans.
Life Cycle Analysis Thinking
Life cycle thinking for the purposes of informing policy decisions is not a new phenomenon – in fact, many of the studies included in the Environment Canada literature review included a life cycle component when evaluating the environmental safety of various packaging types.
However, most contemporary approaches to life cycle analysis, particularly within the context of end of life management of packaging waste, define system boundaries that are too limited in scope. Often times, model boundaries are defined from the point of disposal, to its final end use application (recycling, composting, energy from waste, or landfilling). The environmental impacts of a particular end of life option are compared against a baseline assuming 100% virgin production (i.e. Recycling 1000 tonnes of PET, would be compared against the environmental impacts of producing 1000T of virgin PET, with the delta in LCA key performance indicators being the measured impact)
The vast majority of life cycle analysis specific to waste management and material design is only concerned with what happens to an item once it reaches its end of life. It is through this lense that many plastics, particularly single use plastics, are deemed to be environmentally problematic. In many instances, particularly for light weight and composite plastics, these materials cannot be readily managed in existing waste management infrastructure.They either cannot be recycled or composted, and even when sorted at a material recovery facility, there are limited end markets for most non PET and HDPE plastics.
As a result, the characterization of these materials is often seen as being “bad” for the environment, with many environmentalists and municipalities pointing to the lack of recyclability as being the primary driver for banning single use plastics. In the absence of recycling or reuse, there is no offset to the environmental burdens associated with virgin production of these plastic materials. If these materials end up in a landfill, the risk of entering into our environment and disrupting both aquatic and terrestrial eco systems increases.
While this outcome may lend credence to the decision to ban single use plastics, it fails to account for the upstream impacts (economic, environmental and social) of a material, prior to consumption. In spite of many single use plastics possessing low levels of recyclability, potential benefits attributable to plastic packaging include:
- A reduction in the amount of materials used. The transition to plastics for many products has resulted in the light weighting of materials – less physical material is used to make the product.
- Logistical efficiencies (more material can be transported per shipment) – largely attributed to the reduction in overall weight, the use of light weight and composite plastics has resulted in a reduced emissions footprint related to the transport of materials.
- Increased durability, longer shelf life (both in the store, and in the home), and allowing for discretionary consumption (you only use what you need). This is particularly true of plastic food packaging. As an example, a laminate package for soup (in lieu of the conventional tin can) allows users to reseal the pouch, allowing it to be stored longer and avoiding waste.
This white paper expands the list of criteria for what should be considered in a life cycle analysis, as a means to create more informed and defensible policy decisions.
Expanding life cycle criteria
This white paper recommends expanding the boundaries of a life cycle analysis to capture criteria such as material reduction/light weighting, logistical impacts attributable to light weighting, effects on useful product life (both at the store and in the home for perishable items packaged using plastics), discretionary consumption, direct and indirect economic impacts, available waste management infrastructure, risks when landfilled and risks when incinerated.
Table 1 below summarizes what variables are included in the proposed expanded life cycle analysis. It is important to note that depending on the scenario and circumstances being modeled, not all criteria will apply.
Table 1: Variables to be considered in expanded Life Cycle Analysis
|Primary Production (Raw material extraction)|
|Primary Production (Raw material extraction)|
|Secondary Production (Product Manufacturing)|
|Transport (Virgin extraction to manufacturing)|
|Transport (Manufacturing to end market)|
|Transport (Waste Collection)|
|Transport (Transport to Recycling Center/Landfill/Incinerator)|
|Transport (To End Market Destination)|
|Shelf Life (At store, in home)|
|Design for the Environment|
|Material Reduction (Light weighting)|
|Reuse (Material Durability)|
|End of Life Infrastructure|
|Waste to Energy|
|Material Management Costs|
|Waste to Energy|
|Cost of Composting|
The above KPIs include both quantitative measures (i.e. $ cost per tonne managed,) as well as qualitative variables that provides useful contextual information that can better inform decision making.
While expanding our life cycle approach to capture these variables may result in a more time and data intensive life cycle analysis, adopting this methodology is critical in understanding the “true” impact of plastics, particularly single use plastic packaging. In theory, a comprehensive life cycle analysis is intended to capture the aforementioned components, however, there is little methodological guidance with respect to how to do that, and for which materials can it be applied. Further complicating the inclusion of these additional variables is an issue of measurement – how can we measure things like waste reduction, shelf life etc?