Why compostable plastics are not the only answer

In the wake of the “war on plastics”, demands for more corporate social responsibility when it comes to the environment and consumers calling on businesses to make more sustainable choices,  alternatives to the traditional Polyethylene Terephthalate (PET) plastic have been introduced.

Picture this: You’re enjoying some fruit from your office canteen when you notice something about the plastic pot it came in; printed on the side was “100% compostable plastic”. Compostable plastic? You’ve seen that messaging on plastic disposable products before. Once you’ve finished with the pot and are ready to dispose of it, you’re faced with a dilemma.

What bin do you put it in? The recycling, or general waste bin? You don’t have a compost heap at home, but if you did, would it be better to take it home and compost it there?

The answer is: none of the above.

What does “compostable” mean, exactly?

In a nutshell, compostable plastic is made out of materials that are “capable of breaking down into carbon dioxide, water, and biomass at the same rate as cellulose” without leaving any microplastic or toxic residue behind. They tend to be made out of polylactic acid (PLA), derived from corn starch or sugar cane, and essentially become nutrient-rich fertiliser for plant life once fully composted.

Compostable is not to be confused with biodegradable though; the terms may be used interchangeably, but they are certainly not the same thing. Biodegradable plastics degrade in a similar way, but do so over an undetermined length of time and may leave behind toxic residues and microplastics.

As if to confuse matters more, there are also plastics that are considered “bio-based”, or “bioplastics”. These can be plastics that are either biodegradable but not compostable, or biodegradable and compostable. To be considered a bioplastic, the material must be made from at least 20% renewable resources, like PLA.

Compostable or biodegradable plastics are not recyclable

These alternatives are flooding the market, swiftly making their way into consumers hands, and unfortunately, waste bins. Businesses are moving away from single use plastics, in favour of these “eco-friendly” plastics, in a bid to “be green” without compromising on convenience.

The problem is, consumers are more often than not misled by unsubstantiated “green” marketing claims these companies make, and as such are not educated how to dispose of these products correctly.

These plastics are designed to break down in specific conditions in an industrial composting environment. They need a specific combination of heat, light and water in order to decompose properly; conditions that a home-run composting heap just can’t meet the needs of.

What’s more, these facilities are scarce – in the UK, there are 170 of these plants capable of recycling the material. In the US, this rises to only 185 confirmed facilities. If consumers dispose of these bioplastics improperly, like in my case either in the general waste bin or the recycling bin, it creates an entirely new waste problem.

In a landfill, there isn’t the right environmental controls for them to degrade or decompose. On the other hand, recycling plants can’t process PLA with their PET plastic counterpart; they’re as compatible as oil is in water. Separating them and sending them to the correct facility for processing is costly, in both time and money.

What this means for your business

Bioplastic alternatives pose as much of a threat to the environment, if not more so, than your run-of-the-mill plastics. The three R’s, Reduce, Reuse, Recycle are everywhere. As time passes and the truth about the climate crisis spreads, it’s becoming clearer that the third R cannot always be relied upon, and businesses must move away from disposables, only using them where necessary. Considering the journeys of your products and packaging is key, across consumers as well as employees.

For example, why not provide a bowl of fruit and promote a Bring Your Own message across your staff base? It’s more sustainable than providing them with a product they simply can’t dispose of (I mean, does anyone’s office have a bin labelled “compostables”?) and it promotes corporate social responsibility both internally amongst staff, and externally in the market.

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