Eight Myths About Plastic: Busted!

Posted in: biobased

There are many misconceptions about plastic, particularly biobased plastic. Here, we address some of the most common.
  • We ban plastic for resource efficiency

As plastic products continue to be restricted or even banned outright around the world, there is a growing misconception, particularly among the general public, that this is for resource efficiency, owing to plastic being non-renewable. While it is true that fossil-based plastic is not renewable – a downside not shared with biobased plastic - the real reason behind plastic regulation is simply pollution. The plastic products that are frequently restricted – bags and other packaging, as well as cutlery – are single-use items that are thrown away once finished with. These products can then, if not disposed of correctly, end up in the environment, where they have been shown to cause harm to wildlife both in their raw form, but also after degrading into microplastic particles. This is the chief rationale behind removing these items from the waste stream.

  • Compostable plastic is fine on the compost heap

When compostable alternatives to single-use plastics are brought into mainstream use, it requires a significant public information campaign to accompany them, otherwise the environmental benefits of using these items over non-compostable plastic items will be lost. This is particularly the case when these items are marketed as “biodegradable”, which is, in itself, a misleading term – all plastic is biodegradable eventually, but for most this does not happen on a timescale short enough to be environmentally safe and socially acceptable. Consumers may read this labelling and assume that these plastic items can simply be thrown away, believing they are safe to end up in the environment.

These "biodegradable" labels are more likely to mean "compostable", but even this term can cause confusion. Compostable plastics will either be home compostable, or (more likely) only compostable in industrial composting facilities. It is important for consumers to make that distinction, because compostable plastic will not fully compost in time outside of the correct conditions, and the resulting compost will end up contaminated with un-composted plastic, which can drastically reduce soil quailty (the very opposite effect of what compost should be doing). Thus, it is important that all compostable plastic is clearly labelled with whether it requires industrial composting, or is suitable for home composting, to ensure consumers take the appropriate action.

  • Discarded plastic will stay around forever

In short: of course it doesn’t, but this does not mean it isn’t a problem. Plastic will eventually degrade, but estimates about how long this will take vary greatly, and depend on what ilk of plastic is in question. However, it is not the length of time it takes plastic to biodegrade that is the main environmental issue. In fact, it is what happens beforehand: plastic will fragment in the natural environment, which results in the creation of microplastic particles, which percolate into water courses and soils, causing great damage to wildlife through bioaccumulation. This is the motivation for why certification authorities are looking to develop standards for biodegradable plastics, and how quickly they must biodegrade in different environmental conditions in order to minimise this damage to wildlife. However, the length of time to biodegrade in order to minimise this damage must be very short (though whether the standards will opt for such strictness is another matter), and whether plastics can be developed that conform to such strict standards remains to be seen.

  • There is such thing as a bioplastic

“Bioplastic” is becoming a problematic term within the bioeconomy, as it has no formal definition. There are at least two circumstances in which plastic could be prefixed with “bio”: when plastic is biobased, or biodegradable. These terms are by no means interchangeable, and only sometimes overlap in terms of plastic’s properties. This can create considerable confusion among consumers who, when presented with the word bioplastic, may incorrectly see the plastic as biodegradable and not dispose of it correctly. There needs to be clearer labelling of plastic products to indicate whether they are biobased or biodegradable, and greater public awareness of what biobased really means, not least because…

  • Biobased plastics are automatically sustainable

From a resources perspective, this may well be the case: in theory, by being produced from biomass, they are renewable, but this is not necessarily synonymous with sustainable. The biomass from which the biobased plastic is produced must be grown in a sustainable manner that allows for continued new growth, and this biomass must not be grown where it is interfering with food production, which must always take priority. This is why producers of biobased plastic will conduct full life cycle analyses to ensure there are no unintended environmental ramifications – notably carbon emissions – from utilising certain feedstocks. NNFCC has plenty of experience in assessing the sustainability of biobased products.

  • Plastic cannot be disposed of sustainably

In order to prevent the aforementioned fragmentation of plastics into microparticles, effective disposal of plastic has to be a priority. Wherever possible, plastic manufacturers should make recyclability a priority property, particularly for plastics intended for single-use applications, such as packaging. While recycling can prevent the majority of plastic waste from reaching the environment, this does require recycling infrastructure to be cosmopolitan, which it is not yet. Add to this the fact that most plastics are not infinitely recyclable, and will eventually have deteriorated too much to retain their mechanical properties. In both of these cases, the remaining option to dispose of these plastics without use of landfill is incineration. The concern here is that this results in carbon emissions – effectively solving one environmental problem by creating another – however, it is well-documented that the heat from incineration can be harnessed to produce Energy from Waste, and with advances in Carbon Capture technology, the greenhouse emissions from incineration/EfW can be minimised, mitigating the emissions problem, and generating renewable energy in the process. This would effectively turn biobased plastic into a carbon-negative feedstock for bioenergy, but despite this, EfW should still be the last resort as an end-of-life option for plastic waste.

  • Plastic is always the least sustainable option

With increasing media scrutiny on plastic, there is a lot of hyperbole surrounding the material, and not all of it is justified. Plastic has become an easy target for environmental activists – which is justified, given its impact when released into the environment – but to tarnish plastic as always being less sustainable than other materials is to ignore the wider sustainability picture. Examples of this include clothing, where synthetic polymer fibres have a significantly lower water impact than cotton, which requires regular intensive irrigation when grown; mechanical parts, which are lighter than metal counterparts, and thus are less energy-intensive to operate, resulting in lower indirect emissions from energy generation. This latter effect is well-known: car manufacturers use as much plastic as possible to lighten the vehicles, making them more fuel efficient.

Where sustainability is concerned, applying a broad brush to approaches rarely works – the entire picture must be considered, and that picture is often highly nuanced.

  • Biobased plastics are identical to their fossil-based counterparts

The prescribed function of biobased plastics is to supplant and replace petroleum-derived plastics. This can of course be achieved through producing identical plastics – simply using biomass feedstocks – but this is a very narrow-minded approach. The only necessity in replacing fossil plastics is a retention of function, and the more complex nature of biomass when compared to petroleum allows for greater innovation scope: biobased plastics can also be better plastics. Classic examples include seaweed-derived films that can be used to make consumable drink capsules, eliminating the need for plastic bottles, and biobased PLA-PEG copolymers, which can be used in medical applications and then safely absorbed by the body.

When presented with complex feedstocks such as biomass, it’s little surprise that this challenge drives innovation, and results in market-disrupting materials. Simply looking to replicate existing fossil-based plastics is not ambitious enough.

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This article was written by Bob Horton, Research Analyst at NNFCC.

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