Bioplastics 101: what is truth and what is lore? [Promoted content]

The Packaging and Packaging Waste Regulation (PPWR) is the talk of town in Brussels these days giving rise to studies, deep debate, and controversy, especially in the bioplastics sector. In love and war, all is fair, but in sustainability, the cleanest one ought to win. Unfortunately, misinformation permeates Europe and diffuses across the pond. To clear the water, let’s debunk some of the myths and rectify some inaccuracies around bioplastics and their applications.

Hasso von Pogrell is the Managing Director of European Bioplastics.

Myth #1: Biodegradable plastics don’t really biodegrade.

The central criticism faced by the sector today revolves around certain ‘studies’ claiming that biodegradable products do not biodegrade. The first two questions I would ask those critics are “was the product certified?” and “what standards did you apply?”

A bit of biochemistry. Biodegradation is a process where materials are metabolised into CO2, water, and biomass with the help of microorganisms. This process depends on the conditions (location, temperature, humidity, presence of microorganisms, etc.) of the specific environment (industrial composting plant, garden compost, soil, water, etc.) and the material itself. Consequently, the process and its outcome can vary considerably. 

For example, if a product is designed- and certified- for biodegradation in soil, it will not necessarily do the same, in an equal time frame, in an aquatic environment. This is already highlighted in the various standards that have been developed for biodegradable plastics in the past decades. For compostable packaging in the European market, the most important standard is EN 13432 entitled Requirements for packaging recoverable through composting and biodegradation which simply means that products certified in line with this norm are designed for biodegradation in industrial composting facilities and anaerobic digestion. It stipulates that at least 90% disintegration needs to have taken place after 12 weeks and includes tests on ecotoxicity and heavy metal content. Most importantly, this process will lead to at least 90% of the carbon within the plastic material having been converted to CO2. The remaining share is converted into biomass, which no longer contains any plastic.

Therefore, immersing a package that is meant to biodegrade under specific soil conditions or in industrial composting facilities in the ocean and then coming to the conclusion that it’s not biodegradable, is, at best, naive. 

Nonetheless, some scientists have publicly released ‘ground-breaking’ studies on biodegradable plastics submitted to an aquatic environment and given interviews about how “even after 3 years it didn’t biodegrade”. But if one conducts an experiment that is set to fail before it even has begun, it is not called a ‘scientific finding’, it is called pseudoscience.  

Finally, I would like to reiterate the fact that the promised biodegradation of a plastic in a specific environment does not excuse littering. Littering should never be promoted for any kind of waste, and an according education of end users is crucial. Throwing plastics on the ground trusting they will biodegrade is wishful thinking at best. Littering is not a solution to manage waste. That should go without saying, but it still needs to be asserted time and again. 

Myth #2: Compostable plastics leave microplastic residues in compost.

As stated before, bioplastic products that are certified for industrial compostability are fully biodegradable under industrial composting conditions. Disintegration is a necessary part of the biodegradation process and leads to smaller particles which should not be confused with persistent microplastics. Even in the case of suboptimal compost processing, the biodegradation process of disintegrated plastic particles does not stop. Once the compost reaches the soil, given that it is composted in the manner the standard calls for, the biodegradation process continues. That is it. The microplastic concern from biodegradable plastics is, therefore, overblown at best, and absurd to be more precise. 

Myth #3: Biobased plastics aren’t any better than fossil-based plastics for the environment. 

A key benefit of bioplastics is their contribution to full circularity. The term ‘biobased’ means that the plastic is derived from biomass, which encompasses renewable raw materials such as starch, sugar cane or cellulose. Therefore, when comparing biobased to fossil-based plastics, they have a clear advantage. This is because, unlike fossil-based plastics, they store and repurpose carbon dioxide from the environment. 

Renewable feedstock used to manufacture biobased plastics take up carbon from the atmosphere during the growth process, which is then stored in the plastic products made of it and set free back into the atmosphere, eventually closing the carbon loop. In other words, no additional carbon is emitted in the life cycle of a bioplastic product. What is more, biobased plastics serve every purpose that fossil-based plastics do: they are durable, reusable, and recyclable, with this added bonus of keeping the carbon in a closed loop and without harming ecosystems and emitting further greenhouse gases (GHGs).  

The imperative I emphasise here is that politicians and consumers who wonder “why switch to bioplastics?” have all the data available to make an informed decision when legislating, when having to answer questions, and when purchasing. However, this necessitates more critical reading than click-bait headlines offer. This calls for more information than the pseudoscientific studies posit. Finally, this calls for more circularity than our current system delivers – after all, only with a comprehensive and holistic legislative framework will we manage to de-fossilise the plastics industry.

Less love and war are called for where, instead, facts and figures are needed.