Over the past few years numerous campaigns have attempted to reduce our reliance on plastic. Recently attention has moved from supermarket plastic bags to drink straws and bottle manufacturers.
But has plastic been unfairly demonised? Might bio-derived, biodegradable plastics be kinder to the environment and acceptable to consumers or do these alternatives do more harm than good?
In this webinar, Julie Hill, explores the dilemmas, myths, science and unanswered questions surrounding our use of plastics, drawing on work done by the Green Alliance and WRAP (Waste and Resources Action Programme).
I have role as a member of the Council of the Institution of Environmental Sciences (IES), I Chair the Waste and Resources Action Programme (WRAP) and am an Associate of Green Alliance. WRAP's vision is a world in which resources are used sustainably. It is a not-for-profit organisation working with governments, businesses and communities to deliver practical solutions to improve resource efficiency. We do a huge amount of evidence gathering which we can then translate to action, and have major programmes on food waste prevention and circular economy. Plastics are a theme in a great deal of our work. Green Alliance is a charity and independent think tank focused on achieving ambitious leadership for the environment, and has resources as one of its key themes.
I’m not a chemist or materials specialist, but my interest in all materials led me to write this book, and set out the history and stories of all the things that make up our consumption, and the difficulties of dealing with them at ‘end of life’. The story of plastics is the most complex by far.
Answers submitted ranged from the 1850s to the 1940’s, and several participants had the name and the date. The answer is that the patent for ‘Bakelite’ was filed in 1907.
This is where it began – the picture on the left is the vessel that Leo Baekeland used to produce Bakelite in his home laboratory in Yonkers in New York – the first truly synthetic and moldable plastic. It is a polymer made by combining formaldehyde and phenol (carbolic acid from coal tar) under pressure. The picture on the right is a beautiful Bakelite radio in the Science Museum collection https://collection.sciencemuseum.org.uk/objects/co10394/walnut-bakelite-radio-with-ivory-phenolic-knobs l (carbolic acid from coal tar) under pressure.
The timeline for plastics. Compared to materials that mankind has been using for thousands of year plastic is relatively new (wood, metal, paper, glass).
What’s good about plastics? It has all these great qualities. The pictures show a range of uses that we take for granted, that would be hard to achieve with any other material. Within the main types, there are thousands of variants.
Question – what is the object in the middle of slide 7? Answer- the first artificial heart valve
What’s bad about plastic is same list – the cheapness makes it, in many applications, very disposable – but the durability means that small bits of plastic are a litter problem. Plastic can be recycled, but the variety means that getting critical mass for any one type of plastic is time consuming and expensive, so it is cheaper to buy new. So there is a divide between long-lived products – wind turbine blades, water pipes – that might stay in place for years, and the way we use plastics in packaging and other short-lived applications.
That is why a lot of the imagery around plastics is negative, showing litter and pollution.
This graphic is from Green Alliance work on ocean plastics. The main message is that plastic in the sea has many different sources, but the majority ends up on the ocean floor and we have no idea about the long-term consequences. There is a parallel graphic on the Green Alliance website showing solutions. https://greenallianceblog.org.uk/2017/08/04/five-simple-solutions-to-michael-goves-plastic-problem/
One way to consider the future is to ask ourselves how plastics fit into a more ‘circular economy’. This wrap diagram makes clear that every part of the consumption system has a role. http://www.wrap.org.uk/about-us/about/wrap-and-circular-economy
The Green Alliance diagram adds some detail about where the most loss of materials occurs, and shows the levels of benefits from different strategies – so reuse keeps the most materials in play.
This articulation from the Ellen MacArthur Foundation (EMF) shows the same principles, but elaborates the concept to show two cycles – organic and technical (ie. man-made materials). So might plastics be able to fit into either or both of these? Ideally, on the left hand side, materials that come from the land – bio-feedstocks for plastics – and degrade so they can go back to the land; and/or on the left hand side, man-made materials that can be easily recovered and recycled, multiple times. https://www.ellenmacarthurfoundation.org/circular-economy/interactive-diagram
So recovery – how are we doing with that?
The chart on the left shows EU countries recycling. The chart on the right shows growing plastic demand. So we can see that unless we do better, there will be a growing gap between use and recovery. http://www.plasticseurope.org/documents/document/20161014113313-plastics_the_facts_2016_final_version.pdf
(We are talking about post-consumer plastic, a lot of which is packaging, as it is hard to get good figures for industrial/non-household plastic recycling). The answer is less that 30% - so we’re not doing that well….
This picture from WRAP’s campaign ‘Recycle Now’ illustrates the difficulty – varied, mixed plastics that are often assumed by consumers to be not recyclable at all.
And if we look at plastic packaging alone, we can see from this WRAP flow chart, that we are not doing that well at recycling it.
Some retailers thinking along these lines – simplification of the number of plastics in use for would help, but is not whole story..
Improving recovery is likely to involve a mixture of improvements in the systems we have, starting with consistent messaging to consumers about what materials can be recycled, and which containers to put them in.
But if we go back to our two loops – what about making plastics part of the organics loop?
To do that, plastics would have to be not just bio-derived, so feed stocks from grown materials, but also bio-degradable – it is possible to have bio-derived polymers that are recyclable but not biodegradable. Need to be both to fulfil that left-hand side of the system.
Could bio-degradable plastics solve the marine litter problem? UNEP had a look at the issue in this report.
Unfortunately, at present, it appears not – temperatures are too low.
What about biodegradable plastic as a solution to packaging, especially small bits? (and of course hoping that we can organise ourselves to collect it before it reaches the sea).
Green Alliance did some thinking on this back in 2010– we referred to ‘compostable’ plastic because the point of it being biodegradable is to be able to use composting as a waste treatment option.
Our conclusion was that yes, could have a role, but quite complex to get it to work, so these bullet points set out some conditions.
And this flow chart illustrates the thought process for considering whether biodegradable plastic might be suitable in any given packaging application.
We found that the materials were available, and retailers prepared to consider specifying it, but those on the end of the process - the waste treatment industry, ie. Those doing composting - were very unenthusiastic. They feared that it either wouldn’t work (the picture shows some supposedly compostable cutlery not having composted), or that they would get non-compostable plastics by mistake and have to spend money getting those out. http://www.waste360.com/plastics/bioplastics-burden
And WRAP, as an expert adviser to government on these issues, concluded that there are some major gaps in knowledge here.
And so at present, compostable agricultural film one of few applications considered a good potential use http://sustainingourworld.com/2016/05/04/bioplastics-potential-solution-to-plastic-pollution/
So where do we take plastics in future?
Green Alliance did some renewed thinking on the topic of ‘novel materials’, including bioplastics for this report, published in 2017. http://www.green-alliance.org.uk/circular_economy_novel_materials.php (And IES did a special edition of the journal as part of this work in March 2015) https://www.the-ies.org/resources/new-materials-and-circular-economy
The report identified a group of bioplastics that are at various stages of commercial development, thanks to their in-life or end-of-life advantages. The table below sets out these plastics and provides a crude analysis of how well they perform against our analysis of how bioplastics can contribute to a circular economy. This might be by making it easy to take the polymers back to monomers (a more flexible material with potentially more of a market); by utilising feedstocks from bio-wastes such as crop residue, thus avoiding competition with crops for scarce land; or by being biodegradable.
Finally, this slide gives what I feel are some of the key research questions, but I’m sure participants will have others.
IES Webinar: Good plastic, bad plastic?
Good Plastic, Bad Plastic?
IES Webinar 9th November 2017
What I’d like this session to do:
• Give a sense of the dilemmas we have in shaping
the future of plastics
• Introduce Green Alliance and WRAP work to
explore the potential future of plastics
• Pose the research questions that fall out of that
• Learn your views
Q: When was the first synthetic
Plastic – the new kid on the block
1931: Victrolac (Vinyl for records)
1954: Expanded polystyrene
1960s: HDPE bottles start to replace glass
What’s good about plastic?
• Comes in many different types
• Can take a huge variety forms
• Can be endlessly combined
• Light and easy to transport
What’s bad about plastic?
• Comes in many different types
• Can take a huge variety forms
• Can be endlessly combined
• Light and easy to transport
WRAP and the circular economy
A circular economy is an alternative to a
traditional linear economy (make, use,
dispose) in which we keep resources in use for
as long as possible, extract the maximum value
from them whilst in use, then recover and
regenerate products and materials at the end
of each service life.
A circular economy preserves economic
and environmental value
Improving recovery rates in UK in future likely to hinge on:
• Less confused consumers
• Greater emphasis on including business waste
• Smaller range of plastics, to increase scale
• Less mixing of types, to get purer streams
• ‘Market pull’ – demand for recycled content
• Greater rate of re-use (perhaps deposit schemes)
Concluded that biodegradable plastics ‘would not
bring about a significant decrease in either the
quantity of plastics entering the ocean or the risk of
physical and chemical impacts on the marine
- Most are designed to degrade in industrial
conditions, with higher temperatures
- Those easily degrading (eg used for fishing
tackle) only useful for specific applications
What about packaging? Would it help to
make it biodegradable?
Criteria for Compostable Packaging (2010)
• Material should not cut across or disrupt
established recycling streams for conventional
• Material needs to be easily recognisable as
• The logic of its use needs to be evident, and
aligned with consumer expectations
• Ideally the material should be home compostable
The WRAP perspective
• Still a lot of fundamental science to be done on degradation in
a range of environments – warm and cold.
• Most biodegradeable plastics need oxygen to degrade, so it
does not work well in anaerobic digestion (AD).
• No standard that covers biodegradability in all environments.
• Waste valorisation is a key goal – monomers that can find a
market in new products.
Dilemma: How to get future
plastics to go in the right direction?
Some research questions
• Possibilities for utilising bio-wastes for plastic feedstock
• Making biodegradation work in a range of environments
• Reducing the number of polymers in play while retaining
• Economic ways of producing monomers from secondary
plastics that can find a market in new products.
• Effective messaging to consumers and businesses that ensures
plastic materials are sent down the right route
Thank you – look forward to
questions and views.
Why do authorities never use the number system for
The numbers indicate what the material is, but not whether the local authority has an
available means of recycling it, hence the On-Pack Recycling Label (OPRL) initiative:
Most plastic recycling labels are very small & hard to
read. If they are made much larger and clearer would
this help consumers?
The On-pack Recycling Label scheme was designed to address this problem, and all
feedback welcome: http://www.wrap.org.uk/content/pack-recycling-label
Should biodegradable plastics be collected with other
plastics for recycling and then sorted to go down right
route or would biodegradable plastics be collected via
This might be physically possible, but the extra transport and kit might make it
Demand for secondary plastics seems to be a
challenge - manufacturers only really want PET or
HDPE ... what can be done to increase demands for
secondary materials in plastics?
Demand fluctuates for all secondary plastics. Getting consistent good quality in the
secondary materials is a key factor, and that goes back to improved collection
methods and sorting. Suggestions for ways to boost demand have included a
voluntary or mandatory level of recycled content in packaging (eg Coca Cola’s
commitment to using 50% secondary PET – see http://www.coca-
cola.co.uk/newsroom And/or a levy on packaging that isn’t recyclable, or doesn’t
include recycled content.
Plastic bags a few years ago, straws are rightfully in
the firing line at the moment , what's the other low
There has been talk of taxing single use plastics such as coffee cups and drinks
The isssue with ocean plastics appears to be getting
so acute the problem will not wait for better recycling
routes. Any ideas on how to tackle ocean plastics?
Green Alliance has some suggestions: http://www.green-
also the UN: https://www.treehugger.com/environmental-policy/ and the Ellen
MacArthur Foundation: https://www.ellenmacarthurfoundation.org/news/
Will Brexit change plastic recycling regulations/
The UK may or may not be subject to the EU’s forthcoming Circular Economy
Package, depending on the timing, but I would hope that we would want to do well on
re-use and recycling anyway, because of the great economic and jobs benefits to be
had in establishing new UK businesses. See www.green-alliance.org.uk/employment
With China stopping import of plastic waste, will
Europe upgrade their infrastructure to recycle more or
This probably depends on the economics, but clearly it is a great potential opportunity
to upgrade the recycling and establish UK infrastructure.