Plastic pollution is everywhere. From drinks bottles to disposable cutlery, every day we are seeing items like these – and more! - washing up on our beaches and littering our streets. As the world is waking up to this problem, we are seeing an explosion of interest in bioplastics – the “sustainable” cousin of traditional plastic. But are bioplastics really as ‘good’ as they seem?
What are Bioplastics?
Bioplastics can be defined scientifically as a plastic manufactured from a natural or renewable resource. However, this is not always the case. In reality, the term ‘bioplastics’ covers a range of materials. “Bioplastic is basically anything that people like to call bioplastic,” in the words of Dr. Frederik Wurm, a chemist at the Max Planck Institute of polymer research, Germany. The term can currently also be used to describe a material made from fossil fuels that can ‘biodegrade’. So, what are bioplastics usually made of?
Today, bioplastics can be made from a multitude of renewable resources: plant sugars, corn starch, kiwi skins, wood pulp, even mangos and seaweed! These naturally sourced bioplastics work very similarly to traditional plastics such as PET, the most common plastic used in drinks bottles. However, during production, these bioplastics don’t actually have a smaller carbon footprint than plastics made from petroleum and are often an example of “greenwashing”. This misleading marketing tactic is widely used to improve our image of a product, without always stating all the truth. This is a continual problem facing us today, as we do not yet have a universal definition for a ‘bioplastic’.
Bioplastics versus traditional plastics
In 2023, with our ever-growing problem of plastic pollution, it’s clear that petroleum-based plastics have drawbacks. With our ‘throwaway’ culture, and the popularity of ‘single-use’, a plastic item is often used for a very short time before being disposed of. It has been estimated that the average plastic bag is only used for around 20 minutes before being thrown away. With plastic bags taking up to 1000 years to break down, combined with our imperfect recycling processes, clearly, we have a problem. Not only this, but these items break down into microplastics, leaking toxic chemicals into the environment and leaving behind harmful and invasive particles. Microplastics are now being found in all reaches of the planet, in our seafood and are even finding their way into our bloodstream.
How many types of Bioplastics are there?
Amongst all the different types out there, it can sometimes be difficult to tell the difference between them, what their properties really are, or which one is best for the environment. That’s why, here at Solgaard, we have put together this list to make it easier for you to tell the difference!
Biodegradable
We see this term everywhere - on cutlery, cups, clothes and more - but what does biodegradable really mean? Scientifically speaking, it describes a process where the microorganisms in our environment interact and breakdown the materials of the product into natural substances, such as carbon dioxide, water, or others. It also tends to describe a substance that ‘degrades’ completely, over a measurably short period of time, such as a year. In more basic terms, an item is truly “biodegradable" when it is able to quickly break down in our natural environment, and leave no harmful trace behind. When it comes to bioplastics, this means that no harmful chemicals, or complex disposal processes, should be necessary for these bioplastics to disappear to nothing when disposed of in a compost heap or outdoors. However, oftentimes, this label is used incorrectly, and items that claim to leave no trace in nature, in fact require industrial composting, or specific conditions to be met to decompose as promised.
Plant-based Bioplastics
Although it seems obvious that bioplastics should be “plant-based”, this is not always the case. Confusingly, just because it’s made of a plant, does not mean that the bioplastic will decompose in the natural environment. So why do these types of bioplastics exist? Although moving away from our reliance on petroleum-based products and extractive industries seems like a great idea, we are still facing problems with the imperfect reality of bioplastics like these.
Types of plant-based, biodegradable bioplastics:
- Polylactic acid (PLA) – This is one of the most commonly used bioplastics, created from fermented corn starch. Used mostly in single-use items such as cups, their labels tend to state that they are compostable – but only in industrial facilities!
- Polyhydroxyalkanaotaes (PHAs)
- Polybutylene succinate (PBS)
Petroleum Based Bioplastics
Amongst the family of products that we label as ‘bioplastics’, we often find petroleum-based products hiding behind the term. These are – quite simply – plastics which contain a percentage of ‘plant-based’ polymers, with the rest made up of standard, petroleum-based plastic. This is problematic, as the two types can not be easily separated, resulting in contamination of recycling streams, confusion for consumers, lawmakers, and waste disposal teams alike! Not only this, but as they contain petroleum-based plastic, they will not truly decompose in nature, without leaving harmful microplastics behind.
Petroleum based, bio-degradable bioplastics to watch out for:
- Polybutylene adipate terephthalate (PBAT)
Non-biodegradable Bioplastics
This family of bioplastics seems to be a contradiction. Surely if they are ‘bio’ they should biodegrade, right? Unfortunately, wrong. Many types of bioplastics exist that either require industrial composting (very high temperatures and specific conditions) to decompose, require chemical processes or even incineration to break them down and dispose of them. Their end-product is chemically identical to PET made from oil, so they can still take hundreds of years to fully break down. Although moving away from petroleum products is good news, producing alternatives with the same harmful properties is not.
Types of Non-biodegradable bioplastics to watch out for:
- Bio-based polyethylene (PE)
- Bio-based polypropylene (PP)
- Bio-based polyethylene terephthalate (PET)
- Bio-based polyam-ides (PA)
- Polytrimethylene terephthalate (PTT)
- Polyethylene furanoate (PEF)
Graphic: European Bioplastics Foundation.
So, are Bioplastics really a good alternative?
With market demand for bioplastics booming, and global rates of production predicted by Berlin-based trade association European Bioplastics to reach 2.62 million tonnes, annually by 2023, it would seem like they truly are a great alternative. However, that huge volume is only a measly one percent of the 335 million tonnes of traditional, petroleum-based plastics produced every year. Not only that, but as we have learned, bioplastics are not quite the eco-saviour that we initially thought.
Although producing plastics from plants can help us to move away from our reliance on fossil fuels, in the words of Greenpeace, the environmental non-profit, “plant bottles are not the answer”. This is due to the many problems we still have with producing, categorizing, and disposing of these ‘bio’ plastics. As almost all bioplastics require industrial composting to decompose, simply throwing them in the trash can will not let them biodegrade, and they will pile up in landfills, just like before. As many bioplastics contain a mixed composition of plant and petroleum-based plastics, it is not clear which type of recycling to put them in and can contaminate recycling facilities. Many consumers are not educated on how to dispose of these plastics, resulting in confusion, low uptake of the new products and wrongly disposed of items. As the term ‘bioplastics’ include no singular definition, it remains difficult to regulate them or their usage.
However, the European Commission, as part of its 2018 Circular Economy Action Plan, included bioplastics research as part of their strategy – to increase investment in the movement to create a climate-neutral economy. So, after all, the best, most sustainable thing that you can do at this time, is to choose reusable, durable and long-lived items, that you can keep on using, time and time again.
References
- https://arstechnica.com/science/2020/01/are-bioplastics-all-hype-or-the-future-of-textiles/
- https://greenbusinessbureau.com/green-practices/products/5-types-of-bioplastics-starch-cellulose-protein-organic-aliphatic-polyesters/
- https://docs.european-bioplastics.org/publications/fs/EuBP_FS_What_are_bioplastics.pdf
- https://www.henryford.com/blog/2022/04/microplastics-in-human-bloodstream
Written by Cicely Sinclair
