Composting

Composting

COMPOSTING

A survey of more than 1,000 individuals by the “Grocer” magazine in 2019 found that “consumers think that plant-based compostable plastics are the most environmentally friendly packaging materials,” but most consumers don’t realise that “compostable” plastic does not convert into compost. It is required by EN13432 and ASTM D6400 to convert rapidly into CO₂ gas, and the last thing the planet needs is more CO₂.

There is nothing wrong with composting garden and kitchen waste, but conversion of plastic into CO₂ in a composting facility is a linear process where the material is intended to be wasted, and does not address the main problem facing governments today – that is plastic waste which has escaped into the open environment, from which it cannot realistically be collected for recycling, composting, or anything else.

Plastics marketed as “compostable” are not wanted by the industrial composters or local authorities.

According to the Daily Mail on 30th December 2022 new research by “Sourceful” a Manchester-based supply chain transparency consultancy says that “marketing compostable plastics as good for the planet is ‘greenwashing’” making things appear more eco-friendly than they are.

Sourceful analysed more than 20 materials, including “compostable” plastic and normal garbage bags.  It found “compostable” bags have nearly twice the global warming impact of traditional plastic. Also, “compostable” bags can only properly degrade under high temperatures in special processing plants, but they’re mostly discarded in general waste before being sent to landfill, where they release methane. Ordinary plastic bags, [and oxo-biodegradable plastic bags] on the other hand, emit very little greenhouse gas in landfill because they are relatively inert.”

What is compostable plastic?  This term is used to describe a material that can undergo biological degradation in a compost facility at a rate consistent with other known compostable materials, leaving no visible (toxic) residues. However the term is misleading, because it is often used interchangeably with ‘biodegradable,’ and it suggests that the plastic converts into compost – which it does not.

“Compostable” plastics are marketed for food packaging, bags, cups, plates, cutlery and bio-waste bags.

Sourceful researchers used the European Commission’s Environmental Footprint 3.0 datasets, and examined greenhouse gas emissions of each product’s lifecycle – raw material extraction, film production and end-of-life stages including disposal.  When expanded to other impact categories such as water use and land use, the gap widened to approximately 2.5 times worse than traditional virgin plastic.

On 14th November 2022 the UK Environment 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.”

“Currently there is insufficient industrial composting capacity throughout England to manage compostable plastics at end of life and our call for evidence suggests these materials are often stripped out at the start of the process and landfilled or incinerated.”

On 2^nd December 2022 the 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.  Therefore, our focus will be on reducing unnecessary consumption and working towards a circular economy, not composting of plastics.”

The Co-op supermarket should stop marketing plastic bags as compostable.

MICROPLASTICS

A study by the University of Bayreuth https://www.chemeurope.com/en/news/1176729/  shows that “finished compost from composting plants contains a large number of biodegradable plastic particles. Also, applicable legal and certification standards (EN13432, ASTM D6400 etc) are not violated by the sizes and quantities of the particles detected, so this calls into question the contribution of these standards to effective environmental protection.”

On 15th July 2020 a report appeared in “Waste Management” Vol. 113, Pages 312-318. The conclusions were:

• In many cases, plastic bags are being replaced with compostable plastic bags.
• Industrial composting processes do not completely remove film fragments.
• Compost is thus a potential source of fragments from compostable plastic bags.
• Compostable plastic fragments are then deteriorated in soil to microplastics.
• Compostable microplastic results in an increased number of aflatoxigenic fungi.

LINEAR

The UK Environment Minister continued “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.”

The EU Commission say (Communication 30th November 2022 (COM(2022) 682 final)) “in most of today’s biobased plastic products such as single-use packaging, the carbon initially taken up from the atmosphere is quickly released back” and “As biodegradable plastics are predominantly used in relatively short-lived applications such as food and beverage packaging, the resources used to produce these products are rapidly lost.”

Sending plastic to a composting facility is a deliberate linear disposal route, as EN13432 requires it to convert into CO₂ gas within 180 days. The plastic is therefore intended to be wasted, and conversion of organic materials to CO₂ is not ”recovery.”

A material that converts into CO₂ not into compost, cannot be described as compostable, and action should be taken against companies who are so describing it.

Also, because there are very few industrial composting facilities available, the German courts in Güthoff v Deutsche Umwelthilfe (2014) have held that it is deceptive to market plastic as “compostable.”  Many areas do not have industrial composting plants, and the Welsh Government has refused to invest in them. Bio-based plastics are therefore going to landfill rather than to composting.

RECYCLING

Bio-based “compostable” plastic is also inconsistent with a circular economy because it cannot be re-used or recycled, nor can it be made from recyclate – three very important points which the EU Commission seem not to notice. They are also much more expensive as compared with conventional plastic – an important point at a time when most of the people of Europe are struggling with a cost-of-living crisis.

BIODEGRADABLE?

Many consumers do not know that “compostable” plastic is tested to biodegrade in an industrial composting facility – not in the open environment. In November 2019 a Danish court ruled in Ellepot v Sungrow that “compostable” PLA plant pots must not be described as biodegradable – because they are not biodegradable except in the special conditions found in an industrial composting facility.

The EU Commission say that “plastics labelled as ‘biodegradable’ must always specify the receiving open environment for which they are intended and the required timeframe for their biodegradation, in terms of weeks, months or years. Therefore, plastic certified according to EN13432 for biodegradation in an industrial composting facility (not in the open environment) should not be described as “biodegradable” and the Commission should take action against companies who are doing this.

MORE DECEPTION

The EU Commission say that “To fight greenwashing and avoid misleading consumers, generic claims on plastic products such as ‘bioplastics’ and ‘biobased’ should not be made.”

Although these plastics are marketed as “bio-based” they can contain up to 50% oil-based material, but this is hardly ever mentioned in the marketing material.

The Commission are concerned about deception of the public by marketing a plastic product as “biobased” when the product may contain a substantial component of oil-based plastic. They say “In order to avoid misleading consumers, claims should only refer to the exact and measurable share of biobased plastic content in the product, stating for instance, that the ‘product contains 50% biobased plastic content.’ Action should be taken against companies who are not making this clear.

The Commission added “Documenting the use of biomass through a chain of custody and attributing a share to end-products through mass balance accounting is a method which is not considered suitable for confirming the actual share of biobased content.”

These plastics are often marketed as “renewable” as well as “compostable” but this ignores the fossil fuels used in the agricultural production process by the machines which clear the land, plough the land, bring the seeds to the farm and sow them, harrow the land, bring the fertilisers and pesticides to the farm and spread them, harvest the crop and transport it to the factory, and by the machines which polymerise the raw material.

LAND AND WATER RESOURCES

The Commission also say that “In most cases, the production of biomass requires the use of natural resources such as land and water and the use of chemicals such as fertilisers and pesticides. Therefore, producing plastics from primary biomass can lead to direct or indirect land-use change, which in turn can result in biodiversity loss, ecosystem degradation, deforestation and water scarcity, as well as competition with crops intended for human consumption.”

The Commission are therefore discouraging the use of corn or potato starch to make plastics, (as distinct from materials from non-food sources such as algae, being produced by companies such as Eranova in France).

On 11th September 2003 a Report to the Australian Government by the Nolan-ITU Consultancy concluded that: “biodegradable plastics based on polyolefins (ie oxo-biodegradable plastics) contribute to the amount and nutritive value of the compost because much of the carbon from the plastic is in the form of intermediate oxidation products, humic material and cell biomass.

This is in contrast to hydro-biodegradable polyesters (e.g. starch-based) that biodegrade at rates comparable to purified cellulose. At the end of the commercial composting process, all of the carbon from the latter has been converted to CO₂ so there is a contribution to greenhouse gas levels but not to the value of the compost.”

The same Report concluded that “degradable polymers manufactured from renewable resources (e.g. crops) have greater impacts upon eutrophication due to the application of fertilizers to land.