What is ‘plastic’?

Most of us would think that we can tell whether an item is plastic or made of ‘natural’ materials. A garment has a ‘natural feel’ or a ‘synthetic feel’, but when an item is marketed as plastic-free what does this mean?  It turns out that defining ‘plastic’ in technical terms is far from simple. This is shown by the ongoing discussions at EU level as the details of implementing the Single Use Plastics Directive are thrashed out.

Despite Brexit, the UK’s Resources and Waste Strategy committed the government to “match and where economically practicable exceed the ambition of the EU” on single use plastics, while the Conservatives’ 2019 manifesto stated that the UK would “continue to lead the world in tackling plastics pollution, both in the UK and internationally”.

Problematic material

The Directive, passed in June 2019, is a landmark piece of legislation that aims to stem the tide of plastic waste sweeping into our oceans. It is being widely adopted as a model for regulation by governments in all continents, and so is of considerable global significance.

In an unusually rapid political response to the public outcry at the increasing plastic pollution of our oceans, the EU has approved a strong armoury of measures. These range from banning some single-use items, such as plastic drinking straws and disposable cutlery, to imposing extended producer responsibility (EPR) fees on others. In a ground-breaking move, producer fees will cover litter clean-up costs and even the cost of promoting to consumers the availability of reusable alternatives. The package strongly incentivises producers to look for less-polluting options.

Although there is widespread support for the aims of the Directive and the range of measures included from across society, it seems that the intent of the Directive is now at serious risk of being undermined by one simple question: ‘what is plastic?’

This is an issue that Eunomia flagged up in a report in January of this year, but the draft guidance for Member States, which was widely leaked in June, revealed that the EU was still a long way from resolving this issue, with the document continuing to leave the door open for potentially regrettable substitutions. These could end up being inadvertently incentivised, as producers see opportunities to switch to exempt materials with a similar look and feel to ‘plastics’, thereby avoiding bans and EPR fees. The resulting products could even be marketed as ‘officially’ plastic-free. Unfortunately, the evidence is that, if littered, these substitute materials will be much the same as ‘plastic’, both in terms of their environmental and visual impact.

Malleable definition

Commonly, plastic is defined in terms of its material properties. The term ‘’plastic’’ is derived from the Greek word ”plastikos”, meaning fit for moulding. Plastics are malleable and can therefore be cast, pressed, extruded or moulded into a near infinite variety of shapes used in products that touch every aspect of our lives. The durability of plastic has also come to be recognised as a defining feature, but it is this very ‘quality’ that allows plastic items to persist in the environment, leading to such devastating pollution impacts.

By contrast, the SUP Directive aims to define ‘plastic’ in highly technical terms, based on the chemical structure of the main polymers used and how they were produced. Most plastic is made from chemicals derived from crude oil, but polymers with similar properties can equally be made from other raw materials, including natural gas, cellulose and plant-based starches. The Directive seeks to give the green light to ‘natural polymers’ that occur in the environment, so long as they have not been ‘chemically modified’. The trouble starts when one tries to define what it means to be ‘chemically modified’: what level of change is a ‘modification’; and what types of change qualify?

Chains of reasoning

All plastics are made from polymers – in other words, long repeating chains of simpler molecules – but not all polymers are plastic. Cellulose, for example, is a naturally occurring polymer that makes up a majority of nearly all plants and trees. It is also the main ingredient in paper and cardboard, which were clearly not intended to be regulated as plastics by the SUP Directive.

However, cellulose can also be extracted by dissolving wood pulp in a strong solvent, and by altering the chemical structure slightly to allow the material to be spun into fibres, you end up with viscose. Viscose can be used as a substitute for fossil-fuel based plastics in products such as wet wipes and cigarette filters, or can be made into transparent sheets of cellophane that can be used for snack packaging or formed into drinking straws. All of these products are targeted by the SUP Directive as they were found to be amongst the most common items polluting European beaches, but if made from viscose or cellophane may fall outside its scope.

Wipeout: wet wipes and other plastics flushed down the drain contribute to fatbergs. Photo: Stewart Turkington, courtesy of Thames Water.

And although viscose and other so-called ‘regenerated cellulose’ materials may well offer some real environmental benefits compared to fossil-fuel based plastics, they also come with their own environmental impacts, such as the deforestation and habitat loss and simplification that can accompany the production and harvesting of cellulose. On the crucial matter of their impacts when released into the open environment, Eunomia’s detailed study on the scientific literature published in January left us a long way from being reassured, not least because the body of research on the subject remains woefully underdeveloped.

Implementation

The European Commission is busy working with Member States to resolve these uncertainties, with a view to publishing guidelines for implementation of the SUP Directive in the autumn. Inevitably, they are being lobbied from all directions and given the complexity of the technical arguments, the process may take a while longer.

Over the past few weeks, an alliance of NGOs has mobilised a coordinated campaign, under the pre-existing banner of Break Free from Plastic, to exert pressure on the Commission and Member States to draw the scope of ‘plastic’ widely, so as to include regenerated cellulose materials and packaging that contains multiple servings. A petition launched last week already boasts over 100,000 signatories. But no doubt behind the scenes the counter-arguments are being made by those with a commercial interest in possibly exempt materials.

Straw man argument: campaigners are concerned that EU guidance would allow the production of single use products via material substitution. Image courtesy of Break Free from Plastic.

Hopefully, a route will be found soon that is consistent the intent of the enthusiastic legislators from the 28 (pre-Brexit) Member States who passed the SUP Directive into law. The EU is clearly a key player (globally, perhaps the key player right now) as humanity seeks to address the myriad environmental challenges facing the world. However, it is individual countries and their governments that make the laws that affect what happens (or in this case, what ends up) on the ground. For EU Member States, the Directive sets out minimum requirements, not limits on what Member States can do. And in fact, when it comes to options such as EPR, European law gives specific latitude to countries to regulate all products under the ‘polluter pays’ principle.

With this in mind, there is an alternative solution that avoids getting bogged down in the complex technical issues of defining ‘plastic’. Why not look beyond plastic to all single-use products that have a tendency to be littered? All littered items have the potential to cause negative environmental impacts, albeit that these differ depending on the item and the material. Most of these impacts can be addressed by similar measures to those being targeted at littered items made of plastic.

So perhaps the best way to avoid ‘regrettable substitution’ is actually to stop singling out specific materials, avoid the thorny issue of defining ‘what a plastic is’, and to focus on the impacts of single-use products, and the littering of them, in general. The UK has already indicated that in revising its EPR system for packaging, it will extend the cost recovery principle to all littered packaging. And why stop at packaging?