Debunking the myths behind compostable food packaging

There are many things to celebrate when it comes to compostable food packaging. However, there is some confusion about exactly how they perform, an over-assumption of just how easy they are to revert to their natural elements, and of the ways we should treat them in our daily recycling schedules.

So, let’s take a look at all things compostable and put a few of those misread messages straight.

Not all ‘compostable packaging’ materials are created equal

Let’s consider the humble coffee cup. For the barista of your choice to deliver an added warm and fuzzy feeling on top of your caffeine hit, they sell their coffee in a paper cup branded ‘100% compostable’ on the front.

Sadly, that’s not always entirely true. The marketing departments of many brands are leaning heavily on industry terms and not what we accept by way of society’s descriptions.

We naturally assume that these materials do the same job as the only composting item we’ve come across in our daily lives - garden fertiliser. Occasionally they do; more often, they’re don’t.

In essence, there are two types of material here;

1. Home compostable
2. Industrial compostable

The confusion begins because a material can fall into one of these but not necessarily both.

Why does my coffee cup claim to be compostable if it isn’t?

Because the marketing gods deem it so!

Jumping on the environmental bandwagon is one-way manufacturers can tap into a growing market. The ‘green pound’ is a much sought-after corner of an often-affluent market. With the word ‘compostable’ on cups, paper packs, and more, their users have little guilt throwing them in the bin, or worse still, out of the car window or into the hedgerows on their countryside walks.

They assume that these packaging materials will behave the same way a banana peel or an apple core would, but sadly, it’s far from the truth.

If you want to be sure that your coffee cup is compostable, check to see if it has the Composting Association compostable ‘seedling’ logo. In the UK, they’re the trusted association for delivering the official seal of approval.

This means the pack is ‘home compostable’ and can be composted at home in your compost bin/heap. Or the product may state that it is accredited to EN13432. This means it is industrially compostable and conforms to the EU standard for industrial compostable packaging. In other words, after 180 days (6 months) the product (in industrial composting conditions) will have broken down by at least 90% to biomass, water and carbon dioxide. An interesting fact is that a leaf fails to comply with this!

Due to home composting conditions being hugely variable there is no time limit for home composting.

Are biodegradable and compostable packaging the same thing?

No, they’re not. Compostable materials are designed to decompose into carbon dioxide, water, and a few inorganic compounds. To be labelled industrially compostable, they need to carry out the process within 180 days and by at least 90% of their mass (EN13432).

Being biodegradable isn’t typically based on timescales but often falls into the 180-day limit for pack manufacturers. Otherwise, they could all add biodegradable, eventually! All traditional plastics would need is a disclaimer that their biodegradable timescale is around 500 years!

Do I put compostable packaging in green/garden waste, recycling bin, or general household waste if I don’t compost waste at home?

As simple as this should be, there’s quite a conundrum when it comes to which is the correct bin for compostable packaging.

Most of us see it as a ‘green’ alternative, so put it in the recycling bin. However, most compostable items aren’t currently recycled; those that aren't would contaminate all the recyclable materials in the entire batch, not just your bag or bin.

Local authorities often refuse to include compostable packing as part of their garden or food waste collections, too. There’s a risk of batch contamination there as well, with more hopeful good work ruined. Moreover, different local authorities have different rules for what they can recycle and what they cant.

Presently, there are only 3 industrial composting sites in the UK, so the majority of kerbside collections do not take our waste to one of these facilities. Therefore, the unfortunate truth is, that in the majority of cases, these ‘clever’ materials do not finish their life in the situation they were designed to. They are either landfilled, incinerated, dropped as litter or contaminate existing recycling streams.

If the materials are labelled home compostable and you are lucky enough to have a compost bin at home, then obviously they can be disposed of in this way.

To break down many of the packs labelled industrially compostable materials, burying them in our garden or adding them to the compost heap just won’t cut it. Industrial composting conditions require temperatures of up to 55–60°C, with high humidity and oxygen levels.

You won’t find those conditions in most soils, rivers, streams, ponds, and land sites, so to retain the valuable organic elements of your packs, it takes considerably more than just digging them into the ground.

Industrial composting facilities are built to provide the precise requirements for commercially compostable materials. Knowing which materials are home compostable compared to industrially managed needs to be made clear on the packaging.

Conclusion

In summary, there has been much NPD and innovation in this area and there are many inventive materials that can be utilised.

There are two potential pitfalls to be wary of;

1. The material may not finish where it is designed to finish due to an inadequate waste collection infrastructure. This is, not by any means, the fault of the material but means in most cases that its ingenuity is wasted.
2. The carbon footprint (Life Cycle Analysis LCA) may actually be worse than some of the materials it is designed to substitute such as standard plastics. This may be due, for example, by more energy consumption being required in their manufacture.

If this is combined with 1, then any benefits are negated and the solution could, in a lot of cases, be worse for the planet.

Compostable packaging is best used under the following circumstances;

1. The material has a lower carbon footprint across the life cycle than the material it substitutes
2. The material (if labelled industrially compostable) is sold in local authority areas where waste material is collected kerbside for industrial composting
3. The material (if labelled home compostable) is purchased by end users who have a home composting facility and will dispose of it as such
4. Home or industrially compostable carrier bags sold or given away by retailers for food waste where food waste in that local authority area is collected kerbside for industrial composting

If all these points are taken into account, this type of packaging has a real future as part of the portfolio to pack food in the UK.

19 | 07 | 2022