Biodegradation & Composting

Compostable Plastics Are Not Circular

De Monitor (episode 10/02) about compostable packaging and disposables, has given the discussion about circularity some new oxygen. Jelmer Vierstra, Senior Program Leader Circular Economy at Nature & Environment believes compostable plastics are not circular and compostability standards are irrelevant.

In earlier columns on this platform, Peeze Koffiebranderij and Moonen Packaging already set out their views on the matter. From Nature & Environment I also like to give our vision.

Why is Natuur & Milieu (Nature & Environment) so critical about biodegradable packaging and disposables?

In a circular economy we try to keep resources in the cycle for as long as possible. Biodegradation of plastic is the decomposition of material into carbon dioxide and water.

In fact it is already accepted in advance that material will not get a second life and that is not circular.

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Composting as a process is of course sustainable, but then when it comes to the processing of organic waste and pruning waste. These plant remains also become real compost, that beautiful soil conditioner.

The degradable plastics disappear completely in the best case and in the worst case small pieces of plastic are left behind. In both cases that is undesirable.

Is biodegradable material never useful?

In very specific cases, biodegradable plastic is a good idea. For example, in GFT bags for the bio waste bin at home, or for gluing tea bags and coffee pads together.

In those cases the material (the bags and pads) ensures a higher yield of organic waste and therefore more compost.

In that case, the plastic is actually sacrificed to increase the collection of another stream, namely organic waste. In policy language the so-called ‘ co-benefit ‘ that biodegradable plastic can offer.

What about the European standard of compostability?

We are very critical of that standard. In fact, that standard says that plastic should have been ninety percent perished after twelve weeks. This means that that standard leaves room for ten percent material that does not have to perish.

The idea behind this is that the rest of the material will eventually decay, but that is not always true in practice.

For example, we examined Coop’s meat dish and found a layer of PVDC in it, which is a plastic that does not perish at all. But because that standard leaves ten percent space, this packaging simply meets the standard.

The result is therefore that this standard allows microplastic contamination of compost. Very good that Coop is no longer using this packaging .

The WUR report that was published today has only done research into applications that have a ‘co-benefit’, it is good to read that they all compost pretty well. But that research says nothing about meat dishes, for example.

What about the waste companies that have a too short composting process ?

Waste companies base their processes on the desired quality of the compost that comes out of the process. The costs associated with the length of that process are also decisive.

These companies must balance between process costs and the quality of the compost. In addition, the market for compost is difficult because there is so much animal manure in the Netherlands that they have to compete with.

It makes perfect sense that waste companies do not adapt their process to a European standard for biodegradable plastic. These plastics add nothing to the quality of the compost, which means that the importance for a standard that is consistent with composting practice lies with the producers of the material and not with the waste companies.

How can we make packaging and disposables more sustainable?

In the first place, we have to use much less of it, by opting for reusable solutions where possible. Certainly in an office environment such as a ministry you can serve excellent coffee in regular mugs or glasses.

If a company nevertheless chooses single-use solutions, they must fully focus on recyclability, the use of recycled content and clear communication.

For this it is necessary to greatly reduce the amount of plastics and to keep the design of disposables and packaging as simple as possible. A circular economy starts with a less complex mountain of waste and that starts with less complexity in disposables and packaging.

So shall we continue to use fossil plastics?

That is not the intention and it is not necessary in a circular economy. In addition to using much less single-use plastic, the main challenge is to recycle plastics much better, so that less primary raw material is needed.

At the same time, it will probably not be possible to make plastics 100% circular, the recycling processes always result in material losses.

This means that a stream of ‘new raw material’ is also needed in the long term to close the chain. We have to produce that electricity in a renewable way.

And we have to look carefully at that. Renewable is not automatically the same as sustainable. In practice, renewable means that raw materials come from agricultural processes, but agriculture also has a major impact on our living environment.

The use of residual flows reduces the overall impact, but is also not without sustainability risks.

For example, residual flows are also needed to maintain the soil quality of the field, and you cannot discharge and use it indefinitely.


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Jelmer Vierstra (Natuur & Milieu): “Waarom composteerbare verpakkingen bijna nooit een oplossing zijn”

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