Compostability is often touted as an end of life benefit of some types of packaging, and one that is growing exponentially as more and more innovative biodegradable materials are made possible. The use of composting in general has grown too in recent years as more local authorities offer a food-waste recycling service.
But there has always been a problem with compostable packaging, which can be divided into Compostable packaging and Home Compostable packaging.
Disposing of Home compostable packaging is fairly straightforward, as you just put it in your compost bin. If you don't have a compost bin then you treat it like other compostable packaging. Packaging marked Compostable usually means Industrially Compostable, so it has to be broken down with the addition of heat and water, most likely by anaerobic digestion in a sealed chamber, the same way food waste is recycled. Most green waste is not composted this way, as it is expensive and needs built infrastructure. Green waste is normally sent to a wind row composting facility, where it literally just sits in long rows and is turned from time to time.
So far so good, but here's the problem. Almost all local authorities in the UK do not allow packaging waste to be included either with green garden waste or food waste. Many local authorities will not even accept tea-bags for composting, as they are not always biodegradable. Cardboard is also not popular as a composting material, because it takes longer to breakdown than vegetable matter, even in an anaerobic digester.
Essentially this means that when you see packaging marked as Compostable it is almost certainly not going to be accepted for composting unless you can compost it yourself. A lot of compostable packaging tends to be paper-based, so there is usually the option of putting it in with the recycling, which, in theory, should be a more effective method of disposal than composting, but in reality it is likely to be recycled in mixed kerbside recycling, where it can easily be contaminated with broken glass and food residue, so can be of limited value for reuse.
Some "compostable" packaging, such as biodegradable bio-plastic bags can't be recycled as they will compromise the structural integrity of any recyclate they are mixed with, so there is no realistic method of disposal other than being put into the general household waste. Their environmental benefit is simply that they will break down quickly in the natural environment if discarded outside.
The packaging industry is obsessed with recycling at the expense of alternative disposal options, which suits it just fine. If neither conventional recycling nor composting is suitable for bio-materials (including paper) then the only solution left is Waste to Energy, AKA incineration, an avenue that is increasingly being used for dealing with materials we have put in the recycling bin, believing they would be recycled.
Recycling paper products is not working as well as it should, and composting is a better use than incineration especially for food contact packaging, yet there seems to be no joined up thinking about how to go about opening up composting to packaging.
With the Plastic Pact deadlines looming, retailers are being forced to prioritise recycling as the Go-To option for compliance. Until the infrastructure and, perhaps more importantly, Legislation is in place compostable packaging will continue to lose ground.
If our thoughts excite you, get in touch with Laurel and Stephen at studio@structuralpackaging.com