Michael Stephen Column

Compostable vs Biodegradable, Covid 19 and New British Bioplastic Standard

Michael Stephen, an international expert on bioplastics, shares his thoughts and opinion on important issues impacting the bioplastics industry. Today, Michael writes about compostable vs biodegradable, covid-19 and the new British Standard for OXO-Biodegradable plastic.

“Compostable” and Biodegradable”

This week I need to challenge the monopoly claimed by the “compostable” plastics industry on the use of the words “compostable” and “biodegradable” in relation to plastics.  This is really important, because for many years they have been selling their products at high prices by deceiving the public.  Retailers unwittingly participating in this deception need to be aware that they risk prosecution.

This type of plastic is not in fact compostable, because it does not convert into compost.  It is actually required by EN13432, ASTM D6400, and Australian 4736 to convert almost entirely into CO2 gas.  This is a greenhouse gas which does nothing for the soil and cannot possibly be called compost. 

If you can collect a piece of plastic there are better things to do with it than turn it into CO2.

Oxo-biodegradable plastic will also biodegrade in a composting facility (in accordance with ISO 14855), but the public are not being deceived by a claim that it is “compostable.”  In fact, there is no such thing as compostable plastic. See https://www.biodeg.org/composting/

The “compostable” plastics industry also claim a monopoly on the use of the word “biodegradable” in relation to plastic, and they claim that EN13432 gives them the exclusive right to describe their product as biodegradable.  However, it has been decided by the Danish courts that this is another deceptive claim.  This is because it is tested to biodegrade in the special conditions found in a composting facility – not in the open environment, where consumers would expect it to biodegrade. 

By contrast, oxo-biodegradable plastic is tested (according to ASTM D6954 or BS8472) to biodegrade in the open environment and can therefore be properly described as biodegradable.


It appears that the COVID-19 pandemic has changed consumer behaviour, with a halting of megatrends such as “the circular economy,” with hygiene-concerned consumers opting for single-use plastics one again.  Not only are single use plastics the best way to protect ourselves from contamination, but the plastic itself can be give antimicrobial properties – www.d2p.net  

Tesco has noticed that issues which previously motivated shopper behaviour have dropped in importance in the COVID era.   Last year, surveyed shoppers identified plastic packaging as the leading sustainability concern, but the contamination of food and beverage items has now taken priority over eco-waste.

Plastic waste can still be a problem if it gets into the open environment, so it is all the more important to make it with oxo-biodegradable technology. www.d2w.net

New British Standard for OXO-Biodegradable Plastic

I am glad to see that the British Standards Institute has recently published PAS 9017-2020.  This is an addition to ASTM D6954, BS8472, AFNOR T51-808, SASO 2879 and the other existing Standards for oxo-biodegradable plastic. This new standard can be satisfied by oxo-biodegradable plastic products made by all reputable manufacturers.  I was glad to see that WRAP is excited about the technology – its time that they realised that recycling is not an option for plastic which has escaped into the open environment, and that ordinary plastic urgently needs to be upgraded so that it will not lie or float around for decades.

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.

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