Background
If a single-use plastic packaging solution can’t be eliminated without unintended consequences, or converted to a viable reuse model, then it may be worth considering substitute materials.
One can compare one or more substitutes, with solutions that improve the sustainability of incumbent packaging (i.e., that improve recyclability and/or incorporate recycled content).
Substitutes can be conventional materials like paper, or what the Guide calls “Alternative Materials” (see Fig. 1 below). Conversion to reusable packaging or the incorporation of recycled content are considered distinct options by the Guide.
It’s important to understand that just because a substitute is more recyclable, or uses alternative materials, does not necessarily mean it will reduce negative environmental impacts compared to your incumbent packaging. See this research for more detail.
The comparison of different materials is a strong candidate for life cycle analysis (or LCA) [LINK], to help ground decision-making.
Furthermore, as noted by EMF, when comparing plastic packaging with a conventional material like paper, important considerations include:
- Maximizing recycled content of paper
- Ensuring best-practice sourcing for virgin wood-pulp through existing certification schemes: see for example: PEFC, FSC, SFI.
Categories of Alternative Materials
Alternative materials are generally considered based on their recyclability or compostability, as well as their sourcing, as illustrated in Figure1.
Figure 1. Alternative Materials: Sourcing and End-of-Life
The resulting four quadrants illustrated in Figure 1 include example materials, but is not an exhaustive list of examples. Of note is that some biobased resins are designed for recycling (quad 1), while others are designed for composting (quad 2).
Note too that the 4 quadrants are not mutually exclusive: there are many in-market examples where they are blended. For example, PBAT blended with PLA (grocery bag). Also, see the Goodleaf Use-Case.
Whereas the impacts of fossil-based sources are relatively well understood, our understanding of the impacts of biobased sources is still evolving. For example, LCA alternative material lists are becoming more complete, and resources like the Bioplastic Feedstock Alliance (BFA) Responsible Sourcing provide a helpful framework when considering biobased sources.
Certified Compostable Plastic Packaging
At the current time, this family of solutions has many constraints, and should only be considered for what EMF calls “targeted applications.” Of particular interest to food and produce packaging is the commonly cited target application consisting of “nutrient-contaminated” packaging. The work of the Composting Consortium focusses in this area. An example of targeted applications is food takeout packaging. However reusable packaging has demonstrated viability in this segment and should also be considered.
A number of constraints apply when considering compostable packaging, including certification, availability of composting facilities and the potential for unintended consequences.
Certification
“Certified” compostable is the only type of degradable plastic packaging that should be considered.
As noted by EMF (NPE p. 100) the term “biodegradable” is very broad and can easily be misinterpreted. “Compostable” (industrial or home) has specific requirements, but only “certified compostable” meets essential criteria, like fluorinated chemicals screening (PFAS).
Leading certification bodies include: BPI (North America), BNQ (Canada), and TUV Austria ( Europe).
Lack of Actual Composting
There is little data available for Canada, but it is well understood that almost no compostable plastic packaging, regardless of certification, is actually composted.
- With a few product and jurisdiction specific exceptions Canadian municipalities do not accept these solutions in their organics programs.
- Contamination: organics processors aim to create a clean, high value product, so plastic packaging of any type is typically viewed as a contaminant and removed as early as possible. This is clearly explained in this EEQ Also, when compostable plastic packaging ends up in the recycling stream, it creates quality issues for recyclers.
Organics in Landfill
The vast majority of compostable plastic packaging in Canada goes to landfill. As noted by the Government of Canada, municipal solid waste landfills are responsible for about 23% of Canada’s methane emissions — the result of decades of landfilling of biodegradable waste. Of note too are the findings of this peer-reviewed LCA [attach PDF], which challenge the assumption of PLA as a carbon sink, and offer results that indicate that PLA may generate significant quantities of methane in an anaerobic landfill environment.
Home Compostable
A very low % of Canadians compost at home, and recent evidence indicates about 60% of home compostable plastic packaging does not properly break down anyway.
Special Note: Oxo-degradable and Oxo-biodegradable
The weight of evidence indicates that, currently, these solutions should not be considered. Relevant rationales are published by EMF, Sustainable Packaging Coalition (SPC), BPI and the Association of Plastics Recyclers (APR).
Regulatory Developments
Canadian regulation to be published later in 2023 will address compostability and labelling.
EPR consideration of Alternative Materials in Canada is very limited. In Ontario in 2023, for example, as noted by RPRA, “producers will also be required to report on certified compostable products and packaging, however, there are no collection or resource recovery requirements for certified compostable products and packaging.”
Supporting Resources
- EMF Substitution to compostable flexibles https://ellenmacarthurfoundation.org/substitution-to-compostable-flexibles-design-and-circulation
- EMF Substitution to paper based flexibles https://ellenmacarthurfoundation.org/substitution-to-paper-based-flexibles-design-and-circulation
- Biodegradable and compostable packaging: as green as we think? Eco-Entreprises Quebec (EEQ), 2021 https://ecoconception.eeq.ca/en-ca/reportpackaging
- Designing for Compostability in Canada – National Zero Waste Council http://www.nzwc.ca/Documents/DesignforCompostability.pdf
- Understanding the role of compostable packaging in North America – Sustainable Packaging Coalition, 2021 https://sustainablepackaging.org/wp-content/uploads/2021/01/UnderstandingCompostablePackagingGuide.pdf
- Compostable Products / Packaging – towards common ground – Compost Council of Canada, 2020 http://www.compost.org/wp-content/uploads/2021/03/Towards-Common-Ground-Final.pdf
- Biodegradable and compostable plastics – challenges and opportunities – European Environment Agency, last revised April 2021 https://www.eea.europa.eu/publications/biodegradable-and-compostable-plastics
Definitions
- Biobased: A material is bio-based if it is wholly or partly derived from biomass.
- Biodegradable plastics: designed to biodegrade in a specific medium (water, soil, compost) under certain conditions and in varying periods of time.
- Industrially compostable plastics: designed to biodegrade in the conditions of an industrial composting plant or an industrial anaerobic digestion plant with a subsequent composting step.
- Home compostable plastics: designed to biodegrade in the conditions of a well-managed home composter at lower temperatures than in industrial composting plants. Most of them also biodegrade in industrial composting plants.
- Oxo-degradable plastics: include additives that, through oxidation, lead to their fragmentation into microplastics or chemical decomposition.
- Organic–degradable or enzyme mediated plastics: include additives that lead to their fragmentation into microplastics or chemical decomposition in a biologically active landfill.