The past and future of bioplastics – Expert Reaction

A leading journal looks at how bioplastics have previously been greenwashed  and how they could help solve the global plastics dilemma.

One article in the plastics-focused special issue of Science reviews how early bio-based plastics were neither clean nor green, while other papers look at where bioplastics fit in the circular economy of the future.

The SMC asked experts to comment on bioplastics.

Dr Karyne Rogers, Environmental Scientist – Isotope Biogeochemistry, GNS Science, comments:

“A recent bioplastic authentication paper published in an international journal by scientists at GNS Science found around 50 per cent of in-market bioplastics don’t meet their claims and are subject to greenwashing. Greenwashing is a ploy that many companies use to make their products look more eco-friendly and bioplastics are no exception. Some plastics are coloured green or have ‘bio’ in their brand or name, implying that they are made from bioplastic, when they are not. Some plastic products make bioplastic content claims that are false.

“Incorrectly labelled plastics cause consumer fraud, increase profits for unscrupulous manufacturers and create problems downstream for recycling, as some plastics are not compatible with each other, leading to contamination of large batches of recycled plastics. Bioplastic verification techniques such as radiocarbon dating and stable isotopes are available at GNS Science allowing scientists to determine the actual bio-content of plastics which identify exaggerated or false claims.”

No conflict of interest.

Sarah Heine, CEO, Biopolymer Network, comments:

“It is generally accepted that we need to change the way we use, reuse, dispose of, and what we use with, plastics globally. There are so many initiatives underway to reduce waste and pollution and it is likely there will be a variety of solutions and that new opportunities will keep emerging. The problem is so complex that there won’t be one single answer but a whole range of change will be required.

“Longer term, chemical recycling is likely to be one of the best opportunities to effectively repurpose plastics (both traditional and bio-based) but the uptake of such technologies will be dependent on the cost and availability of infrastructure to process, which will also be dependent on the amount of available plastic for processing. There is a preferred hierarchy of disposal: with reuse being ideal (either through chemical or physical recycling), followed by options such as composting, which keep materials out of landfill.

“Many people are looking for perfect solutions – materials that will be fit for purpose, functional, cheap and will just disappear harmlessly if disposed of incorrectly (many people ask “what will happen if I just throw it in the garden or sea”). While there is a whole range of research and emerging products aiming to satisfy this demand for better materials, we cannot afford to wait for a perfect solution – and so all opportunities that present should be explored.”

Conflict of interest statement: “I work for a company working on PLA (bio-based plastic) foam technologies.”

Note: Biopolymer Network Ltd is a New Zealand research company dedicated to creating products using renewable, natural materials instead of petrochemicals. Biopolymer Network Ltd’s research base is built from three New Zealand research organisations: AgResearch, Plant and Food Research, and Scion.

Associate Professor Johan Verbeek, Director, Plastics Centre of Excellence; and Faculty of Engineering, University of Auckland, comments:

“The attention plastic pollution has received is certainly fully justifiable at the moment. However, the complexity of the issue is generally not appreciated by the public. The complexities of infrastructure, economics and technology make it very difficult to find good solutions, although many exist. In New Zealand the issue is even more difficult because of our geographical isolation and relatively small population. NZ has recently made great strides combatting plastic pollution; the recent announcements on phasing out certain plastics attests to this, however, we are still far away from a truly circular economy for plastics.

“At face value bioplastics would appear to be an attractive solution. However, their reputation has been tainted by materials that didn’t truly biodegrade in the environment; often these matters simply disintegrated into small particles (microplastics). Compostable plastics on the other hand can severely complicate the infrastructure required for mechanical recycling. The term bioplastics is also misleading; it doesn’t mean it is biodegradable (or compostable). Some plastics can be bio-based (i.e. made from natural sources, like PLA or starch) and be biodegradable, but some can be made from natural resources and still not biodegrade, like bio-PET.

“Bioplastics will certainly play an important role in the plastics economy, especially as we move towards circularity beyond only plastics. It is still unclear to what extent these will be adopted by industry. The solution to the plastics pollution problem will be multi-faceted and will take a long time to reach a new equilibrium.

“In the meantime, it is also important to remember the importance of plastics in our society; food quality and medical applications are good examples where we can’t do without this technological marvel. It is how we use it that is important!”

Conflict of interest statement: The Plastics Centre of Excellence is a partnership between the New Zealand Plastics Industry (operating through Plastics New Zealand) and the University of Auckland. In this arrangement, Plastics New Zealand will provide the leadership role for the industry, while the University of Auckland will deliver the research and higher level educational programmes.

Dr Tim Huber, Senior Lecturer, School of Product Design, University of Canterbury, comments:

Comment on: Toward polymer upcycling—adding value and tackling circularity

“The paper provides an excellent description of the difficulties we are facing with plastics recycling. We are dealing with a huge variety of different polymers and additives that require bespoke recycling strategies that we currently do not have in New Zealand.

“However, to be effective we need not only advanced sorting and processing facilities but also need to look beyond solely mechanical recycling of polymers. Chemical recycling is often overlooked in the public but allows us to reduce polymers to simple building blocks to make new and different products. I think we would be well advised to look at both approaches for solutions.

“It might be worth pointing out that neither individual lifestyle changes nor the emergence of bioplastics are sufficient to solve the plastics problem. As the article makes clear, we need a global and holistic approach; support from policymakers to incentivise better practices from local to a global level, improved infrastructure and supply-chains, and a change in consumer behaviour all need to come together for us to minimise and reduce the impact of plastic waste. What could be added is the role product designers could play in making products from recycled materials or that are easier to recycle.”

“The government’s decision to phase out “problem plastics” is a step in the right direction. But I have serious doubts that bioplastics, as we use them today, will be able to fill the gap, as they cannot and should not be a 1:1 substitute. Bioplastics can become an important building block for a future with better and more sustainable plastics use, but without wider systemic change they resemble a band-aid on a gaping wound.”

No conflict of interest.

Florian Graichen, General Manager – Forests to Biobased Products, Scion, comments:

Comment on: The myth of historical bio-based plastics – Early bio-based plastics, which were neither clean nor green, offer lessons for today

“Those who cannot remember the past are condemned to repeat it.

“Most of the plastics we know and use today are derived from fossil carbon (oil, coal and gas) – this common source determines their structure, design, features or way of producing. Just like the stone age did not end because we were running of stones – the fossil age will not end because we are running out of fossil resources. We will use materials that are environmentally and economically sustainable. We are at the beginning of a transition to alternative – renewable – sources of carbon. Instead of digging deeper into the ground and using more fossil carbon (and accelerating climate change) – going forward our liquid fuel, plastics and chemicals will come from three sources of renewable carbon – from recycled products, capturing and utilising atmospheric CO2 or as discussed here from biomass.

“The challenge during this transition will be to rethink plastics – not blindly repeating mistakes from the past. Changing the plastics feedstock will require re-thinking design, manufacture and use of plastics. It will require value chains and networks that we are not seeing yet.” 

Comment on: Achieving a circular bioeconomy for plastics – Designing plastics for assembly and disassembly is essential to closing the resource loop

“System-wide changes such as transitioning to the circular bioeconomy (not only for plastics) require unprecedented collaboration and transparency across industries, government and community. The circular bioeconomy is an important component in achieving future resilience, adaptability and sustainability.

“New Zealand could be one of the big winners of a global transition to circular bioeconomies. The transition is creating employment opportunities across the full set of skills and competencies needed in a multidisciplinary, diverse and innovative biobased sector across rural, coastal and urban areas – uplifting local economies. We can produce food, feed, bio-based products, services and bioenergy while preserving ecosystems. Consumers are increasingly expecting (plastics) manufacturers to switch from fossil fuel-based resources to renewable biobased resources, and to adopt circular economy principles where materials are used and reused efficiently.

“Always remember – plastics is not the issue – it is what we do with it. Plastics are essential but need to be used responsibly. In the context of plastics in a circular bioeconomy it is important to consider the 6Rs:

  • Refuse non-essential plastics & packaging.
  • Reuse plastic products.
  • Reduce plastic use.
  • Redesign products for reuse, recycling or compostability
  • Recycle to keep material in use as long as possible.
  • Renewable resources for new plastics

“The solution for plastics going forward has to be designed in the context of a fossil-free future.

Comment on: Toward polymer upcycling—adding value and tackling circularity

“The most fundamental change we must make is a mind shift. Away from considering the plastics waste dilemma as a “waste challenge”, instead we need to look at it as a resource challenge. Why is that? Looking at scenarios for the 2050 plastics world – the plastics that we know and use today (made from fossil carbon) could be completely substituted by renewable carbon. This is carbon from recycling, captured and utilized atmospheric CO2 and biomass. Recycling (and specifically upcycling instead of downcycling) becomes one of the ways of keeping the “resource carbon” in use instead of letting it go to waste. Plastic is a magical material – upcycling is just one way of ensuring we are able to use plastics for all its benefits going forward.”

Comment on: A binding global agreement to address the life cycle of plastics – To eliminate plastic pollution, a holistic approach is needed

“Government actions are a critical part in mobilising a systemic shift towards a circular economy for plastics – globally and in New Zealand. Phasing out problem plastics and some single-use plastics by July 2025 – as announced recently in New Zealand is a step in the right direction. It also requires industry commitments and innovation around circular and sustainable plastic alternatives. This has to be complemented by circular product design, increased public education and awareness. We have to reinforce each other and hold each other to account on the path to making it a reality.

“Significant support mechanisms – to develop sustainable alternatives – are essential. Addressing the symptoms of this crisis through phasing out and clean-ups is not enough. We need to move away from today’s linear take-make-waste model and fundamentally rethink the way we design, use, and reuse plastics – remembering plastic is not the issue – it is what we do with it. A fundamental re-thinking and tackling the root causes is required, for an economy where plastic is a valuable resource in which it never becomes waste or pollution. Guiding principles should be the “six Rs” – REPLACE – RECYCLE – REUSE – REDUCE – REFUSE – RETHINK – as outlined in the ‘Rethinking Plastics in Aotearoa New Zealand‘ report.”

No conflict of interest declared.