Is biodegradable plastic better than recycled plastic?

When I saw biodegradable plastics start to become available I got excited.  This seemed like a great solution to the plastic waste problem and seemed better than recycled plastic.  However, when you take a step back and look at sustainability as a whole, they aren’t the magical solution you might think.

In reality, a mix of the different types of plastic is probably the best approach (depending on the use).  Although reducing our consumption of the stuff as much as possible is key.  But if you want to know why recycled plastic might still be better overall than biodegradable plastic then read on…

Less new plastic = less CO2 image

Why recycled plastic is often better than biodegradable plastic

1)  The starting point should be what we already have

When it comes to sustainability, our starting point should always be to use what we already have before creating anything new.  There is so much plastic on the planet waiting to be recycled that to create something new would be wasting a resource that we have already created.  And that involves a lot of environmental cost.

Of course it isn’t this simple and it depends on the recycling process involved, but it is a good starting point.

2)  Creating new plastic is energy intensive

Plastic has a large carbon footprint.  Most plastic, including nylon fabric, is made from oil or natural gas.  This has to be extracted from the ground, and is leaked on the way.  Then that raw material has to be turned into plastic resin.  And then more energy is used to turn it into the product you are buying.  In fact, “Plastic is among the most energy-intensive materials to produce.” This is according to Carroll Muffett, head of the Centre for International Environmental Law.

So by using plastic that has already been created you are making further use of some of the energy already used. And preventing further energy being used to create virgin plastic. Although energy will be required to re-process it into something else.

3)  The raw materials aren’t sustainable

Most plastic is made from oil or natural gas, including many biodegradable plastics.  These use microbes to break it down into smaller parts.  So if we want to keep making these fossil-fuel based biodegradable plastics we need to keep extracting the coal and gas for them.

There are also bio-plastics, however, made from things like corn, sugarcane and cellulose.  These are often compostable, rather than just biodegradable.  They are also less carbon intensive but do divert land usage from food.  This may be particularly problematic as the planet warms.

4)  Biodegradable doesn’t equal compostable

According to the Cambridge Dictionary, biodegradable is defined as the ability to decay naturally and in a way that is not harmful to the environment.  However, some ‘biodegradable’ plastics just break down into microplastics.  These are harmful and are therefore not really biodegradable.

Bio-based plastics from things like corn, however, can be compostable (i.e. they actually feed the ground).  This type of plastic can be very useful for disposing of other bio-materials like food scraps because they will break down together and turn into compost to feed the soil.  Just check whether it is home compostable or industrially compostable only (which would need to be collected by your council).

Also bear in mind that when things biodegrade they often produce methane as they breakdown.  Methane is a powerful greenhouse gas.  It is, however, sometimes labelled as ‘biogas’, because it is naturally occurring.  This to me feels like greenwashing.

5)  Dealing with plastic waste

If a plastic is truly biodegradable or compostable, in that it does no harm once it has degraded, it could be part of the solution for dealing with our waste.  However, it is also making that task more complicated because different biodegradable plastics need different conditions to break down properly. This may therefore not happen in landfill.  And some of this plastic is actually contaminating recyclable plastic waste as consumers don’t know how to dispose of it properly.

Recycled plastic is already diverting plastic from landfill in the first place.  And if it can be recycled again that’s even better.  There is so much plastic that already exists and which isn’t being recycled that it does seem crazy to make even more.

The solution is using less

There is definitely space for biodegradable plastics, in particular compostable plastic.  But these need to be properly disposed of as they may not properly break down in landfill.

But beware when something is labelled as biodegradable.  Make sure that you can dispose of it in a way that isn’t harmful.  And remember that when you look at sustainability as much more than how we deal with our waste, recycled plastic may actually be greener.  Which is why we chose to use recycled fibres for our tights, rather than biodegradable.

Overall we need to be reducing the raw materials we consume as much as possible.  This means reducing the amount of plastic we use and making use of what already exists.

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