Michael Stephen Column

Wrap and More Bad News for Compostable Plastics in UK Parliament (FREE)

Today Michael talks about confusing advice given by organisations regarded as experts, and has noticed more bad news for plastics marketed as “compostable,” - this time from the UK Parliament. This is a FREE article


There is a business called WRAP, based in the UK, which tries to advise people on what kind of packaging to use.   They have published an eye-catching leaflet called “Eliminating Problem Plastics,” but they are confusing people when they refer to “Oxo-degradable plastic products.”

They say that “Oxo-degradable plastics fragment into microplastics which contribute to plastic pollution.”  This is perfectly true, but they do not make it clear (as the Consumer Goods Forum does) that this does not apply to oxo-biodegradable plastic products. They will be aware that the European Chemicals Agency studied hundreds of pages of scientific evidence about oxo-biodegradable plastic in 2018 and found no evidence that it creates microplastics.

“Oxo-degradation” is defined by CEN (the European Standards authority) in TR15351 as “degradation identified as resulting from oxidative cleavage of macromolecules.”  This describes ordinary plastics, which abiotically degrade by oxidation in the open environment and create microplastics, but do not become biodegradable except over a very long period of time.

rethinking materials 2023 featured image

By contrast, “oxo-biodegradation is defined by CEN as “degradation resulting from oxidative and cell-mediated phenomena, either simultaneously or successively”.  This means that the plastic quickly degrades by oxidation until its molecular weight is low enough to be accessible to bacteria and fungi, who then recycle it back into nature. These plastics are tested according to ASTM D6954

Confusion caused by organisations like WRAP, who are regarded as experts, is making the plastic pollution problem worse.  This is because people who cannot change to a non-plastic material think they are being advised not to use oxo-biodegradable plastic They therefore continue to use ordinary plastic, which will create microplastics and will accumulate in the environment for many decades.  


The Research Dept. in the House of Commons library has produced a briefing note for legislators on plastic marketed as “compostable.”  This what it says:

  • How much of this gets collected for composting?

There is no data on this or the ultimate destination of compostable plastic. The UK Plastic Pact includes a target to increase the share of plastic packaging effectively recycled or composted to 75% by 2025. However the reporting on progress only includes recycling, not composting, and the underlying data source includes data on paper and wood composting, but not plastic composting.

  • What does the composted material break down to?

The goal of compostable plastic is that it breaks down in specific composting conditions – either at home or in an industrial facility – into biomass, organic and inorganic compounds, CO2 and water, but just because something is labelled as compostable it does not mean that it will degrade into these elements in all environments. A Royal Society of Chemistry Explainer, “Compostable and biodegradable plastics” states that for example, compostable plastics will likely not degrade in the sea or in cold, dry environments and that most established ‘biodegradable’ products rely on industrial composting conditions and will not degrade in home composting conditions or the open environment.

In an annex to the Government’s March 2021 consultation on Extended Producer Responsibility for Packaging, it stated that there was still not enough certainty about whether compostable plastics fully degrade in real world conditions without leaving microplastics behind.

 “Based on the current state of evidence, there cannot be reasonable certainty over whether benefits for the final digestate and compost products result from the use of compostable plastic packaging feedstock. Should the majority of the material break down into only water and gases with no or little biomass contributed to compost or digestate, this would not accord with circular economy principles as it would be more akin to a form of disposal. There also cannot be reasonable certainty that all compostable plastic packaging placed on the UK market can break down fully in the current UK infrastructure or in the wider marine and terrestrial environments.”

Michael Stephen

Michael Stephen is a lawyer and was a member of the United Kingdom Parliament, where he served on the Environment Select Committee. When he left Parliament Symphony Environmental Technologies Plc. attracted his attention because of his interest in the environment. He is now Deputy Chairman of Symphony, which is listed on the AIM market of the London Stock Exchange, and is the founder and Chairman of the Oxo-biodegradable Plastics Association.

Earlier Postings in this Column

All articles of Michael Stephen can be found here

Interview with Michael Stephen


The opinions expressed here by Michael Stephen and other columnists are their own, not those of Bioplasticsnews.com.

rethinking materials 2023 featured image

Leave a Reply

%d bloggers like this: