An organisation calling itself “Compostable Coalition UK” has persuaded some big names, from Tesco, M&S, Ocado, and WWF, to join its advisory board.
Sam Clough from M&S is reported as saying; “..Plastic waste is a difficult problem to solve, and compostables could be part of the solution. But their lifecycle is complex, and the benefits are hard to validate.”
The benefits are certainly hard to validate, because plastic marketed as compostable:
- Does not convert into compost (EN13432 and ASTMD6400 require it to convert into C02 gas)
- Has to be taken to a composting facility, so does not deal with the problem of plastic litter in the environment which cannot realistically be collected. On 2.12.22 the UK Environment Minister said: “Compostable plastics must be treated in industrial composting facilities to be broken down and, when processed incorrectly, can be a source of microplastics and contaminate recycling streams.”
- Cannot be re-used, recycled, or made from recyclate
- Leaves microplastics in the compost, in the open environment, and on land used to grow food. See Biodegradable plastic particles in finished compost
- Is not wanted by industrial composters and local authorities. See Composting on 14.11.22 the UK Minister for the Environment, Lord Benyon, confirmed that bags for food-waste marketed as “compostable” are not useful. He said “evidence suggests these materials are often stripped out at the start of the process and landfilled or incinerated.” They are therefore no better than ordinary plastic bags, and are much more expensive.
- On 14.11.22 the Minister said “UCL’s study into the home composting of plastics has shown that home composting is not a viable destination for managing plastic waste.”
WWF’s Paula Chin is quoted as saying: “Exploring the potential of its contribution to a circular economy is an opportunity which WWF is supportive of …” However, plastic marketed as compostable is deliberately designed for a linear process. The material is intended to be wasted and lost to atmosphere by conversion into CO2 in a composting facility, and there is nothing circular about that. On 2.12.22 The UK Environment Minister said “This packaging does not contribute to a circular economy in the same way as packaging that can be reused or recycled into new packaging or products do, as compostable plastic packaging is generally intended to be used only once.”
On 14.11.22 the Minister said “HM Government is not currently providing any specific support for the development of compostable potato starch bag packaging and have not evaluated the commercial viability of using compostable potato starch bag packaging by government agencies.”
The companies marketing plastic as compostable are certainly good at attracting big names for their public relations efforts, but PR and big names cannot substitute for a product which has no real value. I am amazed that anyone is still buying it.
FUNGI THAT EAT PLASTIC?
I saw a recent article in “Science alert” saying that some scientists in Australia had discovered “Fungi That Can Break Down Tough Plastic in Just 140 Days.” I wondered why these fungi had not consumed all the plastic waste that we see lying or floating around in the environment, so I asked Symphony’s scientists about it.
They advised that abiotic degradation is necessary before exposing the material to the fungi. The method requires exposure UV light, heat, or a chemical reagent, to weaken the waste material so the fungi can attack it. This is why oxo-biodegradable technology is necessary, otherwise the fungi will have to wait a very long time for their meal before natural weathering reduces the molecular weight to the point where they can consume it.
The study was essentially the kind of study mandated by Tier 1 and Tier 2 of ASTM D6954 and BS8472. Symphony’s d2w technology has been tested according to these methods for making plastic biodegradable, for more than 20 years now.
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 Biodegradable Plastics Association.
Earlier Postings in this Column
All articles of Michael Stephen
Interview with Michael Stephen
Questions and Answers on OXO-Biodegradability
The opinions expressed here by Michael Stephen and other columnists are their own, not those of Bioplasticsnews.com