The next big hope for zero waste

The government will soon launch its new bioeconomy strategy. This could put compostables in the spotlight, says David Newman.

Footprint (F): We’ve all heard of the term compostables, but can you explain what it means?

David Newman (DN): By definition, these materials are certified to be compostable within an industrial or home compostable environment. Certification is generally carried out by reputable independent bodies – in the UK it tends to be the Renewable Energy Association. If we’re talking about compostable packaging, the certification has to be carried out to the EU harmonised standard 13432, which was transposed into UK law back in 2000. The testing methodology is well established and materials must be proven to be non-toxic for soil and to biodegrade to at least 90% of their bulk within a 180-day period.

F: So that means they need to be plant- or bio-based?

DN: Not necessarily, though the tendency is towards using a greater proportion of renewable feedstocks. Compostables can be made wholly, partially or not at all from bio-based polymers. The compostability of a material is determined not by its inputs, but by its end-of-life performance: that is, when biodegrading they release water and some CO2 and add a little fibre to soil in the form of humus. So, for instance, an entirely 100% bio-based material may be designed to not be compostable, while a 100% fossil fuel based material can be designed to be compostable.

F: Why would a foodservice company choose compostables?

DN: It depends. Some companies want a material produced with fewer fossil fuels. This would reduce the carbon footprint of the business and potentially provide an interesting narrative to consumers. Some products are also becoming popular because they perform better than their plastic cousins – a longer shelf life, for instance. Indeed, you probably wouldn’t choose compostables on price alone, as they are likely to be more expensive than traditional materials. Many businesses will cite concerns about recycling their packaging – and they want compostables that can be mixed with food waste collections.

F: Will all waste contractors take compostables mixed with food waste?

DN: No. Some plants may not want to compost the more solid compostable plastic packaging as it could slow their process. The compostable pods for coffee machines are one example – some industrial composting sites will take them but in anaerobic digestion [AD] they wouldn’t decompose (they’d be landfilled or incinerated). However, by producing compostable versions we are driving forward the bioeconomy industrial growth which brings with it other benefits to the UK such as investments and employment. The new EU Circular Economy package has included compostable materials within the definition of biowaste, reducing legal obstacles to collection with food waste.

F: What are the main opportunities for compostables in the foodservice sector?

DN: Where materials are collected for food waste collection and destined for composting (that is, where the composted materials can be effectively recycled) – that’s the big opportunity. For example, in locations where on-site collections can be controlled, such as large office buildings, canteens, restaurants, stadia, theatres, cinemas and so on. By collecting single-use plates, cups, cutlery together with leftover food, and sending this to composting, you can achieve virtually zero waste and simplify the in-house waste collections. Scotland already has a number of these initiatives under way.

Another example is where food is packaged for a very short time and the materials can be reasonably expected to be collected with food waste for composting either at home or industrially. Examples of these may be the plastic windows in bread and sandwich bags, or the films and trays for some fruit and vegetables with a short shelf life. (France and Italy have now made it obligatory to use compostable fruit and vegetable bags in supermarkets, and these can be recycled through organic recycling with domestic food waste collections). But the packaging must be clearly labelled as destined for food waste collection or home composting. The sticky labels on fruit and vegetables are also a no-brainer for compostable materials, as they can remain on the skins and go to composting. Likewise teabags and coffee pouches and potentially straws.

F: If it’s that straightforward why haven’t these changes happened yet?

DN: There are some “howevers”. In the UK all packaging materials are often stripped out at the start of the AD process and sent to incineration or landfill, thus losing their intrinsic value. It’s easier to do that than try to identify which is compostable and which is not – there’s a lot of education that still needs to happen. Hopefully, as the UK moves increasingly over to food waste collections (only England does not have compulsory food waste collections now) then these problems will be resolved.

F: What are the other barriers to greater take-up of compostables?

DN: In several types of food packaging, compostables are not yet able to give the performance operators need to guarantee product shelf-life. These include meat, pre-cooked foods, juice cartons and wet-food sachets. But above all compostables are not a solution to on-the-go consumption where the collection and recovery of the materials cannot be guaranteed. Exiting a coffee shop with a cup in hand, the consumer may throw the cup in any one of a dozen places along the street, in the office, at home … and there is no way to control this – the majority of cups end up landfilled or incinerated with mixed waste. Therefore in the short term there is no point in making these products from compostable materials.

Compostables are also not a solution to littering or marine pollution. Littering is a social problem requiring a series of measures including punishment, cleaning infrastructure and collection of waste. While some biomaterial producers are experimenting with products that will naturally biodegrade in the open or in water, it is very dangerous to give out any message that any certain material may “disappear” in the natural environment and compostables certainly do not satisfy that need nor should we want to send out that message.

F: There’s a long way to go, then?

DN: Indeed. It will take huge effort to change from existing “make, sell, throw” materials to ones that have a wider environmental use (don’t forget that in recovering organic matter through food waste collections and treatment, we can fight back and restore soil fertility). It requires collection and treatment infrastructure as well as the will of businesses – and government – to do something new and provide consumers with more choices that can enhance the environment in which we live. Perhaps the bioeconomy strategy will be the start of this. And frankly, given other situations including the Chinese ban on imports, we have no choice but to move very quickly.

David Newman is managing director of the Bio-based and Biodegradable Industries Association.

 

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