Plant-based plastic: how sustainable is the claim?
All you need to know to tell the truth from the greenwashing
Plant-based.... This seems to be the key word today.
And as for any trending word, it often ends up being used for greenwashing. So you can imagine my surprise (or not) when I started to see brands promoting “plant-based packaging”.
My story today is not about plastic packaging, but rather about what we should pay attention to when we see “green” packaging claims.
There are many variations of packaging and plastic, so I decided to pick one example to illustrate the half-truths of plant-based packaging. I chose the well-known bioplastic: PLA (Polylactic acid)
In this story, you will find out:
What criteria make a plastic more environmentally friendly?
What should we pay attention to when see “green” plastic claims?
What can we do as consumer to avoid greenwashing on this topic
📌 Running out of time? Scroll to the end to find a summary of the story.
Taking a look at the footprint
To determine if a bioplastic is better for the environment, one method is to conduct a life-cycle assessment (LCA). It looks at all stages of the life of the product and its environmental impact. How does that look for PLA?
A study published in 2021 focuses precisely on the LCA of PLA. There are three essential stages of the material to look at:
Raw material: what is the plastic made of?
PLA is made from vegetable sources, specifically from lactic acid from the fermentation of starch or sugars - found for example in corn or sugar cane. The study shows that using vegetable sources instead of fossil-fuel sources has positive impact in terms of footprint.
Long story short, corn or sugarcane have absorbed CO2 when growing as opposed to fossil-fuel sources just releasing CO2 when extracted.
Production: the production of any plastic requires energy
Compared to plastics that have been used for decades - like PE, polyethylene - the production of PLA is not that optimised. This means that more energy is needed to produce 1 kg of PLA than for example 1kg of PE.
However, taking into account the positive impact from the raw material, PLA still has a positive impact in terms of footprint compared to fossil-fuel plastic.
End of Life: it refers to what - really - happens to the plastic after it is used. PLA is:
Biodegradable: yes but it will take hundreds of years for PLA to degrade in normal external environment (landfill or elsewhere). So, this is not a very sustainable option.
Compostable: yes, but under industrial composting conditions so you can’t simply throw PLA into your home composter
Recyclable: yes but again, contrary to say PET, there is a lack of facilities that actually recycle PLA. So as a consumer, we can’t simply throw this plastic in any plastic recycling box.
The study put into light the challenges of end of life for any material. PLA that ends up in a landfill or is industrially composted will release greenhouse gases. So taking all stages of its life, PLA has a actually higher footprint than fossil-fuel plastics that can be recycled.
Ultimately, this is the complexity of making packaging more sustainable. And some brands will hide it and simply greenwash their packaging initiatives. So what should we pay attention to?
Greening: what should you be on the lookout for?
Let’s be honest, you and I don’t have time to investigate the footprint of each plastic package that is put in front of us. However, there are a few elements that you can pay attention to, mainly in the area of end of life.
If the packaging claims to be green, consider the following:
if biodegradable, it doesn’t mean much. It could take years for the plastic to actually degrade.
if compostable, is it home compostable? Otherwise, it will require industrial composting services in your area.
if recyclable, can you actually recycle it somewhere? For example, I can only recycle PET in the city I live, that’s it.
The point here is not drown ourselves in guilt for using plastic packaging but rather be critical of shiny press releases from brands that appear to have solved one of the biggest pollution problems we are facing.
Very few biodegradable/home compostable plastics exist today and they are not suitable for all uses.
👉 Avoiding or reusing packaging will go a long way, while we wait for new truly sustainable materials.
📌 In a nutshell
If you ran out of time to read the entire post, here are the key takeaways:
“plant-based” plastic may have a positive environmental impact by using vegetable sources instead of fossil-fuels sources as raw materials
however plant-based plastic may not easily biodegrade, compost or be recycled, which means that its overall environmental impact may not be positive
plant-based plastic is not the silver bullet some brands claim
reusing or recycling conventional plastics or avoiding when possible are impactful actions we should always keep in mind