Informative

A closer look to the disposability of bioplastics

August 31, 2022

It’s logical to think that when we buy bioplastics, that we are doing the right thing for the environment.

Assorted Plastic Bottles. Image retreived from pexels.com

However, more and more alerting messages are appearing which state that bioplastics aren’t environmentally-friendly or even recycled, and still get burned anyways. But is this really such a black and white story? We need to analyze a few factors before we can judge if they really are more sustainable.

Definitions

First, we want to clear up the difference between the various words used in this article.

Biodegradable means the plastic will break down into natural elements, like carbon dioxide, water and biomass, with the help of microorganisms such as bacteria. Depending on the environment in which this takes place (e.g., soil, garbage dump, side of the road or ocean), the speed of biodegradation will differ.

This is where things get tricky:

  • If the conditions are poor, then normally biodegradable plastics may not break down as expected. For example, a warm ocean versus a cold ocean, or the exposed part of a landfill versus the oxygen-poor middle of the landfill, will all have different effects on the speed of biodegradation.
  • If the time taken to biodegrade isn’t specified, then plastics that take thousands of years to degrade could be classified as biodegradable, which is misleading.
  • Also, some biodegradable plastics may only degrade into fragments (microplastics), and not into molecules that nature can make use of.

For these reasons, rigorous standards and certifications must be applied to bioplastics products to ensure that the plastic degrades fully, under a range of conditions, and within a reasonable timeframe.

Compostable materials also break down into natural elements, but only in an environment with very specific, beneficial conditions. Basically, compostable means biodegradable, but with increased specificity: needing the right amount of oxygen, heat, and microorganisms, which are controlled in a specialized facility. If these materials end up in an industrial composting facility, it means that it simply will degrade faster due to more ideal conditions and procedures applied. However, these conditions are artificial and not found in nature, which is why compostable should be considered different to biodegradable. To properly process compostable materials requires them to be separated, collected, and transported to the right locations, which is currently a logistical challenge that many regions are unable to cope with.

Home compostable materials can biodegrade in your garden compost, and have specific certifications which we will talk about in more detail later.

Bio-based plastics are plastics which are made fully or partially from biological sources. These biological sources may be crops, or waste streams from agriculture and other industries. Coming from a renewable resource often makes bioplastics more sustainable than conventional plastics and reduces our reliance on fossil fuels.

Bioplastics is a general term for plastics that are bio-based, or biodegradable, or both. It tends to be a catch-all term, which can be confusing for both consumers and producers. It’s important to know that bio-based plastics are not necessarily biodegradable, and not all biodegradable or compostable plastics are made out of renewable materials. But in order to point out their green origin and/or end-of-life, and to avoid always having to use multiple words to describe these diverse range of materials, they are usually referred to as bioplastics.

Now that we’ve cleared that up, let’s get into how we can be more conscious about the plastics we buy and dispose of.

Geography

Firstly, it depends on the country we live in. Every country (and sometimes even regions within a country) has specific rules which apply to the disposal of organic waste. Focusing on Flanders (Belgium) for example, no compostable or biodegradable plastics are permitted for organic waste disposal, not even when they carry any label or logo. The reason for this is that the composting installations and the composition of the different plastics vary too much to make sure that the systems and materials are compatible to be treated in the right way. Therefore, it is important as a citizen to get informed about your local options to dispose of biodegradable, compostable or eco-plastics. It is also important for countries, regions, bioplastics producers and recycling industries to work together in order to simplify and improve this process.

Reusable versus single-use

Making single-use plastics biodegradable or compostable does not necessarily make them more sustainable. Before buying a product with plastic, one should always consider three questions: what will the plastic be used for, how long it will be used for, and how can it be disposed of when no longer needed? The answers to these questions can clarify whether we truly need that product to be made out of plastic, biodegradable or not. As the disposal and recycling of plastics involves multiple logistical and industrial steps, it is better to opt out of using plastics as much as possible. In these cases, we should remember that “Reduce” or “Refuse” are also sustainable options, and that single-use products might be convenient but are very resource-intensive.

If there is a reusable alternative, always try to opt for that one, for example in the case of cutlery or cups. There are some exceptions however: packaging that is highly contaminated with food scraps cannot be mechanically recycled, and therefore will be incinerated or landfilled. In this case, biodegradable or compostable plastics are considered a better alternative for organic recycling.

Biodegradable, compostable, and home-compostable

Finally, let’s talk about the words ‘biodegradable’ and ‘compostable’ on the labels of our products. When the logo or the label states one of these two words, in Flanders at least, this means that the product still has to go in the waste bin and will be burned. However, there is one global exception. If you see the “OK HOME Compost” label on your product, as is the case for the B4Plastics’ Biorix® straws, you can just compost the product at home. These straws can degrade in 3-6 months in a well-managed composting system. If you find this label on your products, it therefore means that they have this environmentally friendly disposal option available and you can see them degrade in your own compost bin. Some organizations have stated that this is not fully possible, due to natural differences and unideal conditions in compost systems around the world and in people’s gardens. However, as these materials have been specially designed to break down under average composting conditions, we recommend learning how to set up a well-managed composting system for your geographical location.

Outlook

At this point in time, unfortunately not all countries and regions have the possibility to accept biodegradable or compostable plastics in industrial composting facilities. We strongly hope, however, that future development in this area will lead to improved management, allowing for straightforward use and disposal of these bioplastics. With better infrastructure and understanding of the actual users, we can fully enter a New Plastics Economy where fossil fuel or non-biodegradable plastics are replaced by bioplastics, and we can trust that they will be disposed of properly.

There are many aspects that we have not covered in this article, such as the contamination of plastics recycling facilities with bioplastics, the production of methane from landfill-composting plastics, and possible loss of economic value in the composting process. These are all issues worthy of further investigation which we hope to carry out in the future, but are outside the scope of this current article.

For now, we hope that the checklist below will help you to analyze the disposability of a biodegradable, compostable or home-compostable material for yourself, and feel more comfortable in your decision to buy and dispose of bioplastics.

Our recommendations

  1. Stay well informed of the differences between biodegradable, industrially compostable, and home compostable, and what that means for disposal in your country or region.
  2. Pay attention to labels and certifications: in Europe, there are a series of labels that show that your plastic product has been certified to degrade in different conditions. You can see an overview from the European Environment Agency here.
  3. Remember to consider Reducing and Refusing a plastic product first, before Recycling: reusable products are often much more sustainable than single-use products.
  4. If you would like to learn how to create a well-managed composting system where you can dispose of your home compostable plastics, there are some great tutorials online, such as this one by The Eden Project.

 

This article was co-authored by Sil Nevejans and May Elise Sturman.
At B4Plastics, a polymer architecture company which designs new bioplastics for a more sustainable planet, we believe it is our responsibility to clearly communicate to consumers the end-of-life of the products we make, and how to dispose of them correctly.

Sources and further reading

Alaerts, L., Augustinus, M., & Van Acker, K. (2018). Impact of Bio-Based Plastics on Current Recycling of Plastics. Sustainability, 10(5), 1487. doi: 10.3390/su10051487

Barrett, A., & Barrett, V. (2021). The Degradation of Plastics and Polymers (FREE). Retrieved 26 March 2021, from https://bioplasticsnews.com/2021/01/25/degradation-plastic/

Biased interpretation of EEA study on biodegradable and compostable plastics draws wrong image of immature consumer. (2020). Retrieved 26 March 2021, from https://www.european-bioplastics.org/biased-interpretation-of-eea-study-on-biodegradable-and-compostable-plastics-draws-wrong-image-of-immature-consumer/

Biodegradable and compostable plastics — challenges and opportunities. (2020). Retrieved 26 March 2021, from https://www.eea.europa.eu/publications/biodegradable-and-compostable-plastics

Bioplastics. (2021). Retrieved 26 March 2021, from https://www.european-bioplastics.org/bioplastics/

De afdeling Vlaamse Infolijn, d. (2021). Bioplastics – Veelgestelde vragen en antwoorden. Retrieved 26 March 2021, from https://www.ovam.be/bioplastics-veelgestelde-vragen-en-antwoorden#composteren

How to make a compost heap: 10 top tips. (2021). Retrieved 26 March 2021, from https://www.edenproject.com/learn/for-everyone/how-to-make-a-compost-heap-10-top-tips/

Miller, S. (2020). Five Misperceptions Surrounding the Environmental Impacts of Single-Use Plastic. Environmental Science & Technology, 54(22), 14143-14151. doi: 10.1021/acs.est.0c05295

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