A range of eco-plastics: we need new standards biodegradable, compostable and bio-based plastics

Our plastics experts call for new standards for bio-based, biodegradable and compostable plastics

New types of bioplastic – for example, materials claiming to be compostable or made from bio materials – keep appearing. In order to make sure they’re as good as they seem, we need new standards for bio-based, biodegradable and compostable plastics. 

Because while claims made for these new materials are usually true, they may not be the whole picture. For example, bio-sourced materials sound better for the environment than plastics made from fossil fuels. But the amount of energy needed to convert that bio-source into an eco-plastic can be massive. And our energy is mostly from fossil fuels. 

So when the UK government requested evidence to create new standards for biodegradable, compostable and bio-based plastics our plastics team was keen to respond. Dr Stuart Walker, who coordinated the Grantham Centre response, explains below why we need clearer language, evidence-based rules, and why traditional plastic may be better – if it can be re-used. 


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The Grantham Centre for Sustainable Future’s calls for better standards for bio-plastics

A good example of the trouble with bioplastics is compostable packaging. It is true that most items labelled as compostable are – but only in an industrial composter. Unfortunately, they are not compostable in a home compost bin or landfill. 

Users may buy these products based on their environmental claims. But for most of the UK an industrial composting waste stream simply does not exist. As a result, these products end up in landfill, where they do not break down any quicker than conventional plastics.

Another concern is that at present ‘bioplastic’ is used in a range of contexts. It can mean plastics derived from biological feedstock. Or it can mean plastics that are biodegradable (whether fossil or biologically based). And it can describe compostable plastics. So ‘bioplastic’ encompasses a huge range of products and this creates uncertainty for consumers. 

Our suggestions for new standards for bio-based, biodegradable and compostable plastics

The Departments for Business, Energy & Industrial Strategy (BEIS) and Environment Food & Rural Affairs (DEFRA) recently asked UK businesses and academics to contribute evidence for new standards for bio-based, biodegradable and compostable plastics. 

We believe that standards in this area of plastic are key to the redefinition of single use plastic. As such, experts from the Grantham Centre submitted a detailed response.

The 3 key areas we believe need to be addressed are outlined below. These suggestions reflect the fact that we have experts from across many differing disciplines (including social science, engineering and English). And we have created such a diverse team because we want to consider all aspects of plastic use. As a result, we can combine technical data on the requirements of industrial composting with knowledge of the effect of linguistic choices.

Without this multidisciplinary understanding, solutions can only address one aspect of the plastic problem, and may even exacerbate problems in other areas.

1. Standards must be evidence-based

The current standards for bio-based, biodegradable and compostable plastics are not fit for purpose. They must quickly be replaced by more specific standards. One such standard could be a separate ‘home compostable’ one. These standards must be supported by rigorous compliance testing and full life cycle consideration.

2. Language must be clear

Language is key in the development of standards. This is because language is how the responsibilities of citizens are made clear. Too often the verbs used to describe recycling are in a passive form, where the agent is deleted or not clear. As a result, the consumer is led either to take the wrong kind of action or not to act at all.

An example of this is the use of ‘recycle’. ‘Recycle’ is a transitive verb, which means it must relate to a direct object (the thing being recycled), and there must be an agent responsible for the process it describes.

In most examples, the person who occupies the agent role is not made clear. So packaging may state that something is ‘recyclable’, but not who will do that or where or how. Consumers therefore may assume that someone else will take care of it. There isn’t enough information directing them, for example, to remove the cap first, or to take the object to a special kind of recycling facility, and so on. 

Further, the use of the term ‘consumer’ is itself a problem. ‘Consumer’, by definition, describes us as users of a single-use product. This encourages us to use without considering the fate of a product after we have used it.

3. Reuse is better than single-use

Finally, our response reiterated that bioplastics are inherently single-use, and so become waste after just one use. We believe we need to move towards a truly circular model of use wherever possible. Because proper reuse is usually the least damaging option for the environment.

With this in mind, it may actually be better to use plastic rather than bioplastic, as long as plastic objects are made so they can be reused as many times as possible. And when their – long – lifespan is over, they should be recyclable. 


By Stuart Walker and Claire Moran


Interested in how experts can really tell if something is a better option for the environment? Read: What is Life Cycle Analysis?