Our planet is swimming in a soup of pollution, and plastic is a key player. It is now recognised by many nations that the future sustainability of our global economies and societies are heavily dependent upon the health and resilience of our environment. Globally, we have committed to a war against plastic pollution with varying degrees of dedication and success. It is important to remember that “pollution” does not just mean waste – it means the emissions to air, water and land which negatively affect our environment.
What is ‘common’ plastic?
Traditional synthetic plastics are derived from raw fossil resources, mainly crude oil. Oil contains hydrocarbons which, when refined, splits into several petroleum products with varying densities. Some of these products may be used for fuel, waxes and plastic. Naptha is one such product, and is the common compound used to make plastic.
Once extracted, the plastic may be transported to manufacturing sites where it will be transformed into a usable material or product, whether that is packaging, machine parts or commercial goods. These processes are often very energy intensive and consume large amounts of raw materials, fuel and processing water.
The completed products will then be delivered to retailers or directly to consumers, where it will be used for as long as its lifetime and function permits, before being discarded.
Plastic products have varying degrees of recyclability depending on the type of plastic and how it it is used. For example, PET bottles (the plastic bottle delivering your fizzy pop) are highly recyclable, whereas plastic laminates (think the soft plastic packaging your block of cheese comes in) are very difficult to separate and re-use.
Why is plastic so impactful?
Essentially, our common synthetic plastics are entirely dependent on fossil resources, which are the number one contributor to the greenhouse gases driving climate change. We also demand so much plastic that it is incredibly difficult to ensure the 300 million tons of waste generated every year is handled responsibly. It’s a scale issue.
How can we reduce plastic pollution?
The way I see it, there are two main approaches to reducing plastic pollution:
- Focus on decreasing consumption of fossil-derived plastics i.e ‘reduce.’
- Make our use of plastic products more circular i.e. ‘re-use’ and ‘recycle.’
In this series, we are focussing on just one method, which is switching out fossil-based plastic for bio-based plastic.
What are bio-based plastics?
Bio-plastic functionally acts very similarly if not exactly the same as ‘common’ plastics, except the polymers are derived from agriculture crops. This includes corn, wheat, sugar beet and sugar cane. Sugar cane is one of the more commonly used crops. The two main types of bio-plastic are PLA and PHA.
Using bio-polymers drastically reduces the amount of fossil fuel greenhouse gas (GHG) emissions associated with plastic, and encourages divestment away from fossil fuel extraction. Bio-plastics are also able to fulfil the same functions as fossil-based plastic, but can be highly biodegradable when treated correctly at end of life. For these reasons, it is commonly assumed using bio-plastic is an excellent alternative to normal plastic, which can greatly improve the carbon footprint of your company or product. This can absolutely be the case, but there are several pitfalls to side-step first.
Why is your transition to bio-plastic not reducing your climate change impact as much as you thought?
As with most things in life, bio-plastics have a catch. There are three main ways to measure climate change impact: fossil greenhouse gas (GHG) emissions, biogenic GHG emissions and land use change. Developing and using bio-plastics decreases fossil GHG emissions significantly, but it can have the adverse effect on biogenic GHG emissions and land use change. In this series on bio-plastics, we will explore what these challenges are, and how we can work around them.
There are three key challenges for the bio-plastic industry: sustainable agriculture practices, transport of raw materials and managing the waste at the end of life.
Challenge #1: Bio-plastic agriculture practices
India and Brazil compete as the top global sugarcane producers, followed by Thailand, China and parts of Europe. It can be very challenging to quantify the agricultural practices applied in each country though. For example, can you guarantee that protected rainforest space in Brazil is not being cut down to make way for sugar cane crops? Is your supply chain transparent enough to prove that natural green space isn’t being sacrificed for crops? Are the fertilisers, chemicals and other waste elements of agriculture are being handled properly? As a buyer, or procurement specialist, it can be hard to obtain transparency along your supply chain. Due to the uncertainties which often surround sugar cane agriculture in many regions of the world, in our sustainability assessments we assume a worst-case scenario: that natural green space, even rainforest, is lost to provide land for new agriculture. In this worst-case scenario, all too often the bio-plastic material will perform worse than the fossil-based plastic, because of the devastating effects which can be associated with the intensive agriculture practices in vulnerable areas. Not only can the climate change impacts of bio-plastic appear worse from the increased land use impacts, but it almost always performs worse for other environmental impacts like water consumption and eutrophication too. But hey, it’s better to assume the worst and be pleasantly surprised, than to underestimate the full extent of the damage we are inflicting on the planet.
The answer is surprisingly simple: supply chain transparency. This is starting to improve enormously for agriculture. You could achieve this by ensuring your company has direct control over the sugarcane agriculture, or by selecting your bio-plastic suppliers based on how their sustainability is assured. There are non profit, certification bodies designed to assess and verify the sustainability of agricultural practices that you, as the the buyer, can rely on. One example for sugarcane is Bonsucro, a global sugarcane platform which certify sustainable sugarcane production practices. Currently, only 1/4 of the land used for sugarcane growth is registered with a membership to this certification body. However, you do not need to use such a body; you just need to show that your sugarcane is sourced from responsible, sustainable agricultural practices.
Challenge #2: Transport and acquisition
As mentioned previously, most sugarcane crops grown for bio-polymers are derived from South America and Asia. However, when we aren’t producing products in Asia, we are manufacturing our bio-plastic products in local factories across the world. Exports of sugarcane crops from Brazil, India and Thailand are enormous, and may travel to America, Canada, Europe, Scandinavia and Australasia. But how do they get there? Thousands of miles on a shipping container, and then a few hundred more in a truck or on a train? By comparison, often fossil-based plastic does not have to travel so far. The greenhouse gases produced from the fuel consumed by transport can make a significant difference in the environmental performance of bio-plastic.
This is a tricky one, because it is harder to control. If you choose to accept the climate change impacts of the long transport distances, then you can focus on maximising the efficiency of the shipping containers, and pushing to divest the fuels used from fossil fuels and towards more renewable alternatives. Funnily enough, a significant amount of the sugarcane produced in Brazil is also used for fuel-grade ethanol. The alternative option is to start sourcing your bio-plastics more locally, using alternative crops such as corn, or sugar beet. Here, you have to weigh up the short term economic and environmental costs, and the long-term costs too.
Challenge #3: Bio-plastics can contaminate your healthy recycling streams
In a previous blog I explored the restrictions that our current waste management infrastructure enforces on our ability to successfully recycle and properly manage our waste. For example, the bio-plastics PLA and PVC are incredibly incompatible with the PET recycling process. When processed for recycling together, the impurities from PVC plastic can end up mixed in with the PET material, causing it to be rejected from any re-use. PLA can also heavily contaminate the recycling process of PET, and any contamination level above 2% generally results in the recyclable material being rejected for further re-use too.
As a company, if your recycling streams become contaminated due to improper processing (which is not all that uncommon), you may be fined as a result. I understand that this is a consideration when choosing to swap to bio-plastics.
Take matters into your own hands! Some companies are now able to pair with specialised recycling companies to collect back their used products and entirely oversee the waste management process. Are you one of them? This may be entirely possible if you supply products to large organisations such as supermarkets, hospitals or other businesses, who will collect your waste in bulk before having it sent away as waste. If you supply products to individual consumers, there are ways of becoming more circular here too. Organisations such as the Ellen McArthur Foundation have delved into this topic in great detail, and come out with some incredibly interesting and progressive ways to adapt businesses!
Should you be using bio-plastics, or not?
Bio-plastics are an incredibly good step to move away from reliance on fossil-derived products! However, there is little point making the transition to bio-plastics blindly. Here, we have covered what I think are some of the main points you should absolutely consider when investing in bio-plastics. This industry in particular has really great potential, and is still in the early stages of growth. If 67% of the global agricultural area used is for pasture grazing, the amount of land reportedly used to grow crops for bio-plastics falls well under 0.05%. The process needs smoothing out, but this will become easier as the demand for bio-plastics increases.
Focus on transparency through your supply chain, and assess the environmental impacts of your products across their entire life cycle, to truly understand how you can maximise the sustainability of your products.
Alaerts, L., Augustinus, M. & Van Acker, K. 2018. Impact of bio-based plastics on current recycling of plastics. Sustainability 2018, 10, 1487; doi:10.3390/su10051487
Bonsucro. 2019. Bonsucro.
European Bioplastics. 2019. How much land do we really need to produce bio-plastics? European Bioplastics.