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Our director Julie wrote this piece before the publication of the latest IPCC report, which underlines the enormity of climate breakdown, and our latest annual report, which discusses the urgent need for fundamental changes throughout society. Packaging and waste are just two among many areas that we need to tackle as part of the crucial changes needed.
UPDATE, May 2019: As well as taking back your bag tags and carrier bags for reuse, we are now also accepting the clear plastic bags used for salad and leafy greens. We can't reuse these for food hygiene reasons, but we will send them for recycling.
A new study published in The Guardian in April 2019, backs up our conclusions about degradable and compostable materials: "The study found found a lack of clear evidence that biodegradable, oxo-biodegradable and compostable materials offered an environmental advantage over conventional plastics, and the potential for fragmentation into microplastics caused additional concern."
I have become obsessed with plastic and packaging. I am sitting here now, writing, surrounded by piles of carrier bags made of different materials, claiming to be this or that. And I find myself staring at each and every food container, trying to understand what on earth it is made of and what the **** I’m meant to do with it.
Did I mention in my last blog that it’s complicated?! Finding answers is proving to be far from easy – not helped by sometimes actively unhelpful/disingenuous information from manufacturers and retailers (although I suspect some of the manufacturers are just confused too…).
To be fair (to all of us) it’s clear that the systems and products we need to have in place to deal with this issue simply don’t exist yet and some of the ‘solutions’ that are emerging turn out to cause more problems than they solve. There is currently a gaping chasm between what makes sense in theory and what is possible in practice.
Context is critical here. Any solutions proffered by manufacturers and retailers (particularly those with the scale and buying power to invest in this complex arena) need to work in practical terms in relation to the systems that currently exist. But alongside that, we need to redesign systems and take active responsibility for managing and influencing what happens all along the chain. And of course, we need government action too.
The government’s new Waste and Resources Strategy is expected to be published before the end of the year. It is likely to consider the following:
And in terms of fiscal measures, the treasury is considering using the tax system to:
The government confirmed plans to consult on a packaging tax and Packaging Producer Responsibility reforms in the most recent Budget, but nothing is due to be implemented before 2022.
Many moving parts and uncertainties, but I do wonder why supermarkets and shops are promoting biodegradability and ‘compostability’ with a vengeance when they must know this will cause more problems in the short term and I would argue in the longer term too. But more about that later.
I guess it’s because compostable bags are an example of a drop-in solution that also happens to play very well with a concerned public. And let’s face it, most of us don’t really want to change our behaviour that much. Manufacturers and retailers are no different, so options that enable business to continue as usual are preferable to something requiring a radical overhaul of systems and business models. We want to be able to carry on the way we are, continuing to use the incredibly complex industrial processes and supply chains that currently exist while not changing our behaviour too much.
Food packaging is of course just one element of the whole packaging jigsaw. Many of our current uses of plastic packaging should simply not exist – products sourced and produced in a way that requires such high-impact packaging and distribution systems to get them to us.
But food is a challenge to get from field to table safely; long supply chains with multiple actors compound the challenge. It’s often easier to process the food: stop it decomposing, fill it with preservatives and package it to extend shelf life, but much of the goodness can be lost and in some cases is replaced by things that are actively detrimental to health. So, access to fresh food – particularly fruit and veg – is important if we are to address many of the diet-related health issues in our society.
And when it comes to food, waste is more significant than packaging in terms of climate change (according to WRAP food waste in the UK is responsible for over 20 MtCO2e whereas all packaging in the UK including non-food packaging is responsible for 17.4 MtCO2e). So, the balance needs to be found where plastic can be most usefully used to stop food being wasted. I’d argue that if you were to prioritise any sector to get a reasonable piece of the packaging pie, then a good case could be made for food (along with medical supplies).
The supermarkets have their work cut out though: their business model cannot really cope with the loose produce, local sourcing or short supply chains required to reduce the need for packaging on fresh food. Fortunately, GC has always challenged this dominant model of food supply and as a result our systems are already redesigned to a large extent. Our direct suppliers, the collection and return schemes we promote, the emphasis on sourcing according to seasonality and perishability. We are already very different from most food retailers and supermarkets.
And it’s worth adding that if you live in the UK your chances of your plastic packaging ending up in the oceans is small – the main routes being littering and badly managed landfill sites. As George Monbiot wrote in the Guardian in September: “As for the bags and bottles contributing to the disaster, the great majority arise in poorer nations, without good disposal systems. But because this point was not made, we look to the wrong places for solutions.”
But, we are far from complacent. In my last blog I identified two areas where we are reviewing our approach: the veg carrier bag and the salad and leaves bag. Let’s continue with that story…. There’s a long read – if you want me to take you through the tortuous route we’ve been navigating over the last few months – or for a short read, skip to the Tentative Conclusions section at the end.
More about types of plastics
Plastics can be made from petrochemicals or from plants.
A plant-based source is renewable and a petrochemical resource finite.
A material that contains some plant-based material is generally known as a bio-plastic, but the plant-based element doesn’t have to be all or even most of the content to use the term bio.
Both plant-based plastics and petrochemical-based plastics come in forms that can be non-biodegradable which makes them durable or biodegradable which means they break down over time.
A plant-based plastic is chemically identical to its petrochemical-based equivalent.
A note of caution!
Some bags are being wrongly sold as biodegradable and these should probably be banned or reported to Trading Standards. These bags are in fact regular plastics derived from fossil fuels with chemicals added to make them break up in the presence of light and oxygen – but they persist in the environment. The correct term for these bags is oxo-degradable.
I also came across Biothene in my travels. Turns out to be an oxo biodegradable plastic i.e. polythene with an additive added to make it break up into smaller bits of plastic. Completely different to Bio-ethylene – which is a plant-based version of polythene made from sugar (and potentially a good thing). Took me a while to get my head round that one but best beware the term ‘bio’!
More about recyclability
To have the potential to be recyclable a plastic must be durable/non-biodegradable. E.g. polythene (petrochemical-based) or bio-ethylene (plant-based). Bio-ethylene can in theory be recycled alongside polythene as it is chemically the same (bio-ethylene being made from sugar instead of oil).
Plastics are generally downcycled. In theory recycling could be like for like (e.g. from a bag to a bag) but in practice this generally doesn’t happen. This may change as volumes increase and there is more separation of waste streams, but at the moment there is minimal separation of different types of plastic through municipal waste collection systems. When they are recycled, plastic bags and films can be made into refuse sacks, benches, playground equipment…. Occasionally bags are recycled into new plastic bags.
More about compostability
To have the potential to be compostable a plastic must be bio-degradable e.g. PBAT (Polybutylene adipate terephthalate, which is petrochemical based) or PLA (Polylactic acid, which is plant-based).
Is compostable the same as biodegradable? Well, not quite. Compostability is at the far end of the biodegradable scale i.e. a plastic (whether plant based or petrochemical based) that breaks down in a relatively short time and under certain conditions. So, all compostable plastics are biodegradable but not all biodegradable plastics are compostable.
There are currently two definitions of compostability: industrial composting requires elevated temperatures (55-60°C), high relative humidity and the presence of oxygen. Compliance with EN 13432 is considered a good measure for a plastic that will break down sufficiently quickly under industrial composting conditions.
Home composting works under much lower and less stable temperatures than industrial composting. There is no CEN [European Committee for Standardisation/Comité Européen de Normalisation] standard for plastics that are suitable for home composting, but several countries have developed and applied national standards for testing and certifying of home compostable materials. But not the UK.
Bags composted under either of these definitions help with compost structure but don’t add any nutrients to the compost . So, at best it is a neutral process i.e. it does no harm rather than actively adding anything good (such as nitrogen, phosphorous or potassium) to the resultant compost.
Comparing the environmental impact of different options
The environmental impact of different packaging and plastics options depends on many factors, not just the type of material and the manufacturing process e.g. the distances travelled during and after the manufacturing process, whether materials have been produced by conventional or organic farming, any land use change involved, how many times the item is consequently reused, whether it is recycled, and how it is disposed of. Environmental impacts will generally be lower where:
A study which considers all these elements is called a Life Cycle Analysis (LCA)
Reusability vs recyclability vs compostability
YOU CAN’T ARGUE WITH REUSING! I’m shouting this because it is the one beacon of clarity in this murky world I have found myself in. We should reuse as much as possible whichever kind of material we start with. If it can be reused, it should be reused!
Using a recycled product (if available) is better than using one made of virgin feedstock (bio or fossil fuel based). So, recycling a plastic into something that would otherwise have required the use of virgin feedstock is generally a good idea. But! If it becomes something that’s just a bit crap that would never really have existed otherwise, then that’s pointless – probably better to extract any residual energy left in the material (by an energy from waste process or anaerobic digestion) and move on.
Compostable materials are generally not recyclable. So, recyclability and compostability are currently mutually exclusive options.
I would argue that given the choice we should choose recyclability over compostability – mainly because of the LCA issues already outlined but also because, at the moment, just because something can in theory be composted doesn’t mean it will be. And if it isn’t, it is likely to cause more problems and have a greater negative impact by contaminating recycling streams or producing methane in landfill.
In Hackney, there is currently no municipal recycling of plastic films or bags. We do have a food waste collection system (the kerb-side, blue-bin system) and the council issues us with compostable bags (PLA) to be used alongside that system. I had assumed until very recently that the food waste collected here went on to be industrially composted, but I was thrown by a presentation at a recent Soil Association packaging event where one of the presenters stated that there were no industrial composting facilities available in the UK yet and, furthermore, that most councils actually remove all bags from their food waste regardless (apart from – we assume – the PLA ones they distribute to residents specifically for food bins), as this is less time consuming than trying to differentiate between the genuinely compostable bags and all the others that end up in there. So, all very confusing. We are following up with Hackney in relation to all these issues and will keep you posted. (If you have any info please do let us know.)
For one-off food use where it can be difficult to remove food remains from the bag, compostability makes sense. This should be the exception, not the rule. And we need to think very carefully about what happens to these bags in practice.
I am considering an additional rule: only 100% renewable/plant-based materials should be made into materials designed to be composted after one use. Not because I can prove any issue in relation to toxicity or can find any LCA data, but because instinctively it feels like using a resource that has taken millions of years to make, then composting it after one use, just seems to not be the most skilful approach to take.
Ultimately – as with energy – we need to wean ourselves off fossil fuel sources for plastics production if we are to move to a sustainable society and have any hope of mitigating the impact of climate breakdown. And eventually, all virgin feedstock for plastics production need to come from a renewable/plant-based source.
But unlike energy use – where the product literally goes up in smoke – the plastics we have already made will hang around for a long time, along with all the embodied energy that went into their extraction and manufacture. So, it makes sense to get the best use out of all that energy by reusing and recycling them for as long as we can. The fact that they have come from a petrochemical source isn’t necessarily a problem. Any inevitable losses from the system could then ideally be topped up with a renewable material. NB it is far from clear how sustainably any of the plant-based plastics currently on the market are being produced (although the Natureflex film we are considering for the salad bags is from FSC certified forests.)
The other key element of this approach is that when it comes to the end of its useful life, a material needs to end up in the right treatment stream. That relies on us all agreeing what those streams should be (we don’t), those streams being put in place consistently across the country/world (they aren’t yet), products being labelled accurately (they aren’t), industrial processes and product being adapted accordingly (time will tell) and all of us doing the right thing (we might if we knew what the right thing to do was). So, plenty to be getting on with….
But since my last blog, I am even more convinced by this Circular Plastics Economy approach. I have summarised my take on it below.
1. Reduce our overall use
Why: Reduces the pressure on virgin feedstock and reduces the need for and impact of extraction/land use and manufacturing.
How: System and product development to design out waste and unnecessary packaging. Supported by customer education and behaviour change. (GC are already in a good place in relation to this – bag system, short supply chains, perishability.)
2. Reuse what we do use
Why: As above. Whatever material we use, it makes sense to use it as many times as possible.
How: System and product development to design in reuse. Supported by customer education.
3. Recycle what we can and use recycled products where these exist
Why: Recycling uses less energy than manufacturing from virgin feedstock. Sourcing recycled and recyclable helps to stimulate the market.
How: Customer information and accurate labelling. Active intervention where municipal systems are not yet in place.
4. Compost only when the situation justifies this
Why: Compostability raises more problems than it solves. It should be reserved for necessary one-off use when it’s difficult to separate food from its packaging.
How: Customer information and accurate labelling to ensure these bags are composted and do not go into either general waste or other recycling streams. Active intervention where municipal systems are not yet in place.
5. Gradually replace the petrochemical-based elements with plant-based/renewable ones, to replace inevitable losses from the system.
Why: They may not be a golden bullet but plant-based/renewable plastics are part of the longer-term solution.
How: Consider sourcing plant-based materials but not at the expense of recyclable and recycled options. And be mindful to source sustainably produced materials. And as with energy and the biofuels dilemma – be mindful of the land use impact of using land to grow feedstock for plastics.
6. Dispose responsibly. Anaerobic digestion or energy from waste. Avoid landfill and litter.
Why: Important to recoup as much of the embodied energy from the product as possible and avoid the problems associated with landfill and littering (marine pollution being one of the highest profile and worrying elements of this).
How: Source products that are recyclable or – if the specific circumstances warrant this – compostable. Educate and communicate with customers to ensure correct disposal happens and consider active intervention if facilities are not available.
In practice this means the following sourcing hierarchy:
> Reuse items already in the system that would otherwise
> Source recycled materials where available
> Source recyclable products
> Source a bio-based or part bio-based product
> Source a compostable product only where
specific circumstances justify this.
And if there seems to be a choice, aim to identify the material with the lowest LCA
The areas we have set out to investigate are the veg carrier bag system and the bags we use for salads and leafy greens. (See previous blog for details.)
Veg Carrier Bag System
Our original aim was to conduct a mini LCA and comparison of the following carrier bag options
1: status quo: customers returned bags topped up with recycled blue/green bags as necessary. Loop-lock tag attached to bag to identify product.
2: fabric (nylon, polyester/rPet)
3: multiple use plastic (LDPE) – often called “bags for life”
In the process of our research, lightweight NWPP, bio-ethylene and a compostable polymer blend (Mater bi) emerged as additional possibilities. We looked at the following issues:
System design and compatibility
As I said in the last blog – the collection system has been shown to contribute very positively towards our overall carbon footprint. Other organic veg schemes with UK-wide distribution systems and door-to-door delivery can have 76% of their carbon footprints coming from transport emissions. An additional comparison worth making is to look at the cardboard box that many delivery-based systems use. A box has many more times CO2 in a full life cycle analysis (think how much more material there is in a cardboard box compared with a paper bag, which already has 3-9 times the carbon footprint of a 'single use' plastic carrier bag – see below). The cardboard also means that some things (e.g. heads of chard) need bagging whereas in a plastic bag they do not. i.e. the plastic bag provides protection whereas the cardboard absorbs moisture from the veg. So the plastic carrier bag also helps support the ‘mainly loose’ approach.
So, we’ll stick with our packing and distribution systems as they provide a solid place to start with.
In terms of compatibility with that system we need to find a lightweight, strong and flexible receptacle (i.e. a bag) that is better than our current system. We have already ruled out cotton, hemp, canvas, jute, NWPP (80g or above) as they are incompatible: too rigid, bulky, heavy, porous, hard to clean or a combination of these. (Even if cotton were compatible – turns out we would need to reuse it at least 131 times to be ‘better’ than an HDPE bag and over a thousand times to be better than our current system – see later.)
We started testing paper, although it is not ideal for our system – being heavy, bulky, inflexible and unreliable when wet – but we thought we would try it. When we realised that it needed to reused at least three times to be better than polythene (which is frankly not viable – the paper just doesn’t hold out that long) we ditched the trail. No point. To add insult to injury, turns out that if paper ends ups in landfill it is worse than plastic, because it gives off methane (plastic doesn’t – unless it’s biodegradable or compostable).
Reusability is the next issue.
An Environment Agency study from 2006 showed that the amount of primary use required to take reusable bags below the global warming potential of an HDPE bag (High density polyethylene i.e. your average “single use” plastic bag) was as follows:
So, if the HDPE bag were used just once (as in the first column) it would take 3 uses of a paper bag or 131 uses of a cotton bag to be ‘better’ than that. If the HDPE bag were in turn reused 3 times (as in the final column), then the numbers would go up to 9 and 393 respectively.
Not sure what the equivalent score for a bag in our system is but it must be considerably less than the 1 the HDPE represents: many bags are already in the system and considered to be waste until we reuse them, the top-up bags are made from recycled plastic and therefore less than a virgin HDPE bag. Perhaps 0.3? If we factor this in, then a paper bag would need to be used – oh I don’t know – 27 times and the cotton 1179 times…
So, on this basis alone, its looks like it’s going to be hard to compete with our current system.
We investigated lightweight (30g) NWPP – a picture of an example in Morocco showed potential and we got hold of a similar sample that had been acquired on holiday. If 80g NWPP needs to be reused 11 times to be better than HDPE, in theory 30g should require considerably less – but we haven’t been able to confirm that. The samples we looked at were strong, but we have been unable to find a source at the time of writing.
On to Nylon. We can find no data to make a direct comparison with the EA study, but indications are that nylon is as bad as cotton in terms of energy consumption in manufacture. We think this is due to the woven nature of the fabric (and is why NWPP – a non-woven fabric – conversely uses less energy in manufacture). This chart from the International Journal of Life Sciences shows what a big slice of the life-cycle eco-cost of woven textiles is taken up by spinning and weaving.
So, we are assuming we would need to use a nylon bag as many times as the cotton one. Getting a bag reused between 131 – 1179 times (and possibly more to make it better than HDPE) is simply not going to happen and is more than we can reasonably expect in terms of customer behaviour i.e. every bag returned every week by every customer for up to 22 years. I’m 55 and if I succeeded in returning a bag every week for 22 years I would probably insist on having it buried with me – which would give a whole new meaning to the term ‘Bag for Life’!
We investigated rPET as it is an already recycled product (PET is Polyethylene terephthalate, a member of the polyester family but rPET is moulded (bottles) and polyester is a fibre. So, in most respects PET and Polyester are synonymous) and this would automatically reduce the return rates required to justify its use. But – according to that earlier diagram, seems like rPET is woven and therefore similar to nylon.
Ok – on to sourcing
We followed up on various ‘biodegradable' and 'compostable' bag options (before we knew better – see earlier). None of the 100% plant-based and compostable carrier bags (generally made of PLA/corn starch) were strong enough to be reused and had a weirdly stretchy quality. We came across a bag made of Mater bi – made by an Italian company – that was strong, and plant based and fully compostable – but it turned out to use only 30-40% renewable source material. The rest is fossil fuel-based source material. Mater bi is aiming to eventually be 100% renewable/plant based. But, I’m very far from convinced that this approach is sensible – in the short term it is likely to lead to more problems, in the longer term…. But anyway, this type of bag is currently beyond our scale of operation in terms of the size and numbers we would need to suit our operation. So, a theoretical discussion as far as we are concerned. We can revisit it in a few years’ time.
Then we explored bio-ethylene. Got quite excited about this for while. It's plastic made from sugar that is as strong, durable and light as polythene! Turned out not to be so simple. While the manufacturer Braskem commissioned an LCA which showed a negative CO2 profile, we'd need an independent peer-reviewed study to put any store in this and were unable to find one. And as all the source materials are grown in Brazil, we began to look at what might be happening on the ground in terms of land use change and whether production was sustainable. In the meantime, I looked into pricing and orders and it turned out to be way beyond our scale of operation. So, we left it there for now.
We looked at polythene (HDPE) – it can be recycled and there is a relatively well-established recycling industry that we should be able to tap into and return bags to when we can no longer reuse them. In theory they would be able to take bio-ethylene in the future. Polythene bags would be accessible to us in terms of sizes, colours and price.
We investigated recycled polythene. Polythene is usually downcycled (into darker coloured or more solid items e.g. bin liners etc) but could in theory be recycled back into bags. But we couldn’t find any at the moment; the market doesn’t currently exist.
Then we looked at NWPP and rPET – see earlier section on reusability.
The bag for salads and leafy greens
At the time of the last blog, we were just about to test three new compostable films made of Natureflex – a plant-based plastic made from wood pulp/cellulose.
But we learnt that Riverford had identified the same films and was in the process of testing and developing a compostable bag for their salads and leafy greens. So, we contacted them, and they are happy to share results with us and enable us to source the bag when it comes into production. So potentially very exciting!
But, as you can tell from the earlier sections of this post, I have become distinctly less enamoured of compostability over the subsequent weeks.
To be honest, I’m not sure it is possible to properly weigh up all the options in a way that is intellectually rigorous: too many assumptions; too little data looking at the whole process; too much room for behaviour to affect the results; too many changes that need to be put in place to truly make any of the current ‘solutions’ make sense. Too many moving parts.
But at GC we want to do something that is supporting moves in the right direction. And we don’t want to do something that might sound like a good idea in theory but in practice will cause more problems. And some ‘solutions’ just seem to support business as usual. Ultimately we have to change our eating and buying habits and dramatically reduce the amount of packaging we use, wherever it comes from.
So, we’ve examined our systems and policies thoroughly and will aim to make them as good as they can be while working to support positive developments in the meantime, such as helping to create markets for recycled products. This is where we’ve got to:
Veg carrier bag
Having been around the houses examining the pros and cons of various other options we have finally concluded that without a shadow of a doubt the best thing we can do now is to stick with our current system.
Using bags that are already in the wider system – that would otherwise become waste – and then reusing them many more times than they would otherwise have been used is by far the best environmental action we can currently take. It is a positively good thing that GC are contributing to the overall system and will actively reduce GC’s carbon footprint. It’s a bit like carbon sequestering
So, we're going to stick with it and hopefully improve it by encouraging customers to return any bags they have. We will explore getting bags from schools and directly from the supermarket return systems. As Hackney do not currently recycle bags (they end up in landfill or the incinerator), once they wear out, we will aim to actively intervene in the disposal process by getting them recycled into refuse bags.
The system relies on you to return your bags and us to have systems to support that. But, it is a great system that we can make even better and perhaps we should be crowing about it, not feeling persecuted and guilty.
Salads and greens bag
This is more problematic. The Riverford bag won’t be available until the new year at the earliest, but in the meantime, my feelings about compostability have hardened. Context is all important and I’m not sure that our situation here in Hackney is compatible with or justifies a single-use compostable bag.
We are investigating the use of Ziplock polythene bags for the Hackney Salad. These are already used by Wild County Organics who supply our veg scheme and have a stall at our farmers’ market. Ziplock would remove the need for heat sealing while actively lending themselves to more reuse by customers.
And we can encourage their reuse to extend the life of other items in the veg bag e.g. carrots, cucumbers. Look out for my next blog post: fridge management and veg storage. (Not quite what I fantasised about dedicating my life to when I was a young girl, but then again, reducing food waste is a critical issue when it comes to climate change.)
The whole lot should be recyclable at the end – via the same company we are exploring for the veg carrier bag. And we’re also going to explore sourcing recycled bags for salad. They are not on the market yet and we are too small alone to create a demand, but perhaps with Adrian Izzard and the rest of the growers on board, we can have an impact.
So, we’ll get on with all that while we wait for the Riverford compostable salad bag to emerge. When it does, we will reassess things. I think you can argue the case between recyclable polythene vs compostable Natureflex either way. It will depend on the specific circumstances and how actively we are able to promote reuse and improve disposal.
When the number of reused bags in the system drops, we will review the options available to us. We are likely to favour a recycled option (possibly part bio-based) that is in turn recyclable. Or perhaps an rPET or lightweight NWPP fabric bag will make sense at that point.
Hopefully, it will also be clearer what impact biodegradable bags are having on council composting and recycling services. As the market develops, options that were previously unavailable may become accessible to smaller players like us.
I feel a bit sad to not have a shiny new proposal to roll out – with lovely branded bags – but I guess our brand is about striving to do the right thing, even if it doesn’t look quite so good.
But I love the idea of working towards a future where we can source recycled polythene salad bags, which are then reused by customers at home to keep our amazing veg fresh for longer, and are then returned to us and recycled again. Or what about a recyclable bio-ethylene bag but made from EU-grown corn instead of Brazilian sugar? Or better still, a recyclable bio-ethylene bag made from UK-grown organic corn.
Oh, what the hell! What about a recycled and recyclable bio-ethylene bag made from London-grown organic sugar beet (the leaves of which have been removed and sold through our veg scheme and farmers’ market – sugar beet leaves having turned out to be the latest superfood discovery) and which after being reused by our customers are then returned to us for recycling into crates to be used in our packing yard. Then after many years of stalwart service are recycled into benches for use at the farmers’ market.