Beyond the bin: Rethinking bioplastic waste for a circular future

Mail & Guardian

2 days ago

Bioplastics are made from renewable sources, which sounds ideal, but some are compostable or biodegradable only under certain conditions. Now Stellenbosch University has found that enzymes may be the solution.. Photo: Sustainable Seas Trust
Plastic is everywhere. From packaging our food to building our homes and medical equipment, we've come to rely on it for nearly everything. But our dependence on plastic has come at a cost that the environment can no longer bear.
We now know that plastic pollution is choking our oceans, polluting soils, harming wildlife, and posing a threat to human health. That's why this
One solution that has garnered considerable attention is bioplastics. These materials resemble regular plastics in appearance and function but are made from renewable sources, such as corn or sugarcane, and often are certified as biodegradable or compostable. It sounds like a dream: plastic without the pollution.
But the reality is more complicated. Not all bioplastics are created equal. Some are biodegradable, meaning they can break down naturally, but only under specific conditions. Others are compostable, but only in large-scale industrial composting facilities, not your backyard compost heap. Still others are bio-based versions of conventional plastics and don't degrade at all.
Another key issue is that evidence suggests certifications are not aligned with real-world outcomes. Authorities are now addressing this through a review process, specifically to bring the EN13432 compostable certification — a European standard that defines the requirements for packaging recoverable through composting and biodegradation — closer in line with real-world end-of-life scenarios. The bottom line? These materials are often misunderstood by consumers, companies and even governments.
Many people assume that tossing a bioplastic item into nature or a regular bin is fine, but without the right conditions, most of these materials don't degrade within the timeframes for which they were certified. Even worse, if they're sent to waste management facilities already processing other waste streams, such as PET recycling facilities that handle polyethylene terephthalate — a strong and durable plastic — they can disrupt and jeopardise these processes.
Above all, when bioplastics are mismanaged, we lose valuable carbon that could have been recovered and reused, thereby undermining the very purpose for which these materials were created.
The truth is that our waste systems are not designed to handle bioplastics, at least not now and not at scale.
Take Italy, for example. The country has made significant progress in encouraging the use of bioplastics, even mandating their use for shopping bags, takeaway containers and the collection of organic waste. These bioplastics are legally required to be sent to organic waste management facilities, such as composters and anaerobic digestion plants.
Despite good intentions, much of the bioplastic-containing waste is pulled out at the start of the treatment process, along with other large or 'unusual' items, and sent to incineration instead. Why? Because old treatment plants weren't designed to handle large quantities of bioplastics. This leads the facilities to believe that the risk of disrupting their processes is just too high to treat bioplastics properly.
The problem isn't with bioplastics themselves; they can and should be a big part of the portfolio of solutions to combat plastic pollution. It's that existing waste management systems weren't built around them. Moreover, in the developing world, most cities lack proper industrial composting or anaerobic digestion facilities. There's little public awareness on how to dispose of bioplastics correctly. And our recycling technologies haven't caught up with the complexity of these new materials. As a result, the promise of bioplastics is falling short. But it doesn't have to be this way.
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This means that less bioplastic waste is sent to landfills or incinerators, but also that we get as much value as possible from bioplastic materials before they are composted. It's a system designed not just to clean up plastic, but to recapture carbon — the most valuable currency in the world — and keep it cycling in the economy where it belongs.
Of course, new technologies are only part of the solution. Public education is just as important. Most people still don't understand the difference between biodegradable and compostable, or how to identify a bioplastic in the first place. Clear labelling, public awareness, consistent regulations and accessible disposal systems are essential. It's also time for governments to step up.
There is a need for investment in composting and recycling infrastructure, as well as extended producer responsibility laws that hold companies accountable for the waste their products generate. Additionally, incentives are necessary to encourage better product design and effective product management after use.
Crucially, we must be honest about where bioplastics make the most sense. They're great for short-lived, disposable items, such as food packaging or compostable liners, where collection and treatment can be controlled. But they're not a blanket replacement for all plastic. In some cases, reusable options or better recycling systems offer more environmental benefits.
Bioplastics won't fix our waste crisis overnight. They're not a silver bullet. But, with innovative design, responsible production, as well as proper disposal and waste management systems, they can be part of a much-needed shift toward circular, sustainable materials. And that's the future we need. One where resources aren't wasted, ecosystems aren't harmed, and people, businesses and governments work together to protect the only home we have.
Consumers, too, have a role to play. Start by reading labels carefully. If something is labelled 'compostable,' it usually means it needs the high heat and controlled conditions of an industrial composting facility — not your backyard bin.
So, compost carefully, and where possible, check if your local waste system accepts compostable plastics. If not, advocate for better infrastructure. Try to reduce single-use items altogether and support companies developing genuinely sustainable alternatives.
Every action counts. When we work together, scientists, citizens, companies and cities, we can shape a future where waste is not just managed but transformed into a resource.
Dominique Rocher is a co-tutelage PhD researcher at Stellenbosch University (SU) and the University of Padova. Dr Wessel Myburgh is a post-doctoral researcher at SU and the University of Padova. They are co-founders of Urobo Biotech, a waste-to-value spinout focused on enzymatic solutions for bioplastic-rich waste streams
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