Michael Stephen Column

Oxomar, UK Government and Microplastics

Michael Stephen, an international expert on bioplastics, shares his thoughts and opinion on important issues impacting the bioplastics industry. Today, Michael writes about Oxomar, UK Government and Microplastics


Last month the case for oxo-biodegradable (as distinct from oxo-degradable) plastic was strengthened considerably, because a five-year study (the Oxomar Study), has now proved beyond doubt that oxo-biodegradable plastic does biodegrade in the oceans much more quickly than ordinary plastic, and is non-toxic.  The report of the study has been submitted to the French National Agency for Research (ANR) who had sponsored the research.

The report provides comprehensive and reliable scientific data on the performance of oxo-biodegradable plastic in the oceans. The study had a multidisciplinary approach including physics, chemistry, and biology.

The report confirms the findings of the scientists in their September 2020 interim report that “Oxo-biodegradable plastics biodegrade in seawater and do so with a significantly higher efficiency than conventional plastics,” and that “The oxidation level obtained due to the d2w prodegradant catalyst was found to be of crucial importance in the degradation process.”

The Oxomar Report confirms the studies by Queen Mary University London, who applied different scientific techniques to prove biodegradation of d2w plastic in the marine environment, leaving no toxic residues.  

The study has dynamically combined and compared tests and studies performed directly in marine conditions as well as under laboratory conditions. Bacterial strains found in marine waters were used and incubated in marine waters under temperature conditions (> 18°C) usually found in the ocean.

The study has proved that the plastic biodegradation processes observed in laboratory conditions are transferable to real life marine conditions. The scientists have specifically confirmed that accelerated weathering does not invalidate the results of experiments.

Toxicity testing in Oxomar was more thorough than in any previous studies, and a wide variety of marine creatures at different trophic levels were examined. 

Scientific articles arising from this study have already been published in scientific journals, and results have been presented at 13 international conferences.

UK Government

I have just seen the government’s long-delayed response to the Call for Evidence made by BEIS on 22nd July 2019, to which the OPA responded on 11th October 2019.

There has not been enough time for the OPA to analyse this latest paper, but it is already apparent that the government has missed an opportunity to make a useful contribution to the debate. 

First it fails to address the main issue facing governments today where plastic is concerned.  This is the pollution caused by plastic which escapes collection and finds its way into the open environment, where it can lie or float around for many decades, and where it accumulates every day. However, most of the government’s paper is concerned with bio-based and biodegradable plastics which are not designed to biodegrade in the open environment and are often marketed as “compostable.”

As regular readers of this column will know, plastic marketed as “compostable” is an expensive irrelevance.  It is a classic example of a linear product because it cannot be recycled, and is intended to be taken to a composting facility and wasted by being converted into CO2 – not into compost. (See EN13432, which requires rapid conversion of at least 90% into CO2).  It is claimed that this type of plastic assists the disposal of food waste, but it is not wanted even by the industrial composters and local authorities. see website  

The technology which has been specifically designed to address the main issue is oxo-biodegradable plastic, which biodegrades very much more quickly than ordinary plastic in the open environment, but the government’s paper dismisses this, subject to a public consultation, in one short paragraph.  The OPA will of course be participating in the consultation, and will be drawing attention to the very important new evidence from the Oxomar study, which was not available to the government when they published their paper.

The UK government relies on the HSAC study, to which the OPA has published a critique 

Apart from this, the government relies not on evidence but on the opinions of the well-known opponents of oxo-biodegradable plastic who responded to the consultation. 

The government congratulates the UK Plastics Pact, whose subscribers say “We are creating a circular economy for plastics, capturing their value by keeping them in the economy and out of the natural environment.” I agree with this, but even they would not claim that they have reduced plastic pollution to zero.  If they had achieved this there would no longer be any public concern about plastic pollution and I would not be recommending oxo-biodegradable plastic to the UK government. 

The fact is however that thousands of tons of plastic are still getting into the open environment every week, and the government is pretending that this is not happening.  They are ignoring this present danger and are simply continuing their efforts to achieve zero pollution.

The Plastic Pact describes oxo-degradable plastic as “problematic” because it fragments into microplastics.  This is true, but the Pact says nothing about oxo-biodegradable plastic which, was created to prevent microplastics polluting the environment, not to create them. The European Chemicals Agency was not convinced that oxo biodegradable plastic created microplastics so who is convinced, and who has found these so-called oxo-biodegradable microplastics?


I noticed the other day a short video by a company called Polymateria which shows in graphic form why oxo-biodegradable plastics don’t create microplastics.  Essentially microplastics are formed when the long, entangled, polymer chains within the polymer structure of ordinary plastics become damaged by sunlight, resulting in embrittlement and fragmentation, but the molecular weight of even those damaged chains is far too high for microorganisms to make use of them as food.

So, what the oxo-biodegradation process does is to modify the molecular structure of the plastic itself so that it becomes an entirely different material with none of the characteristics of a plastic, forming a waxy material which can be consumed by the bacteria and fungi, and recycled back into nature. Unlike the degradation of ordinary plastics, the process continues once initiated, even in the absence of sunlight.

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

Interview with Michael Stephen


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

%d bloggers like this: