Our series EcoHomeLife Explains aims at lighting up some of the darker areas around the subject of sustainability. In this edition, we answer the question: are bioplastics sustainable?
During my research into living a more sustainable life, I came across a lot of terms and concepts that I needed to learn more about.
One of those are bioplastics. It certainly sounds like a good thing, after all it has “bio” in it. But as so often, not everything is as good as it sounds.
So in this part of our series we will answer the question: are bioplastics sustainable?
Bioplastics Definition
Before we delve into our question, let’s find out what bioplastic actually is. According to the Cambridge Dictionary online it is:
plastic made from plant materials rather than oil
Cambridge Dictionary online
So this means that the source material for bioplastics isn’t petroleum, i.e. fossil fuels, but plant material, such as sugar or starch.
Although bioplastic has a different source material than traditional plastic, it has the same chemical structure.
I have seen eco-friendly brands advertise their products as plastic-free, but when looking more closely, it turned out that they were using bioplastic.
Whether this was greenwashing or a misunderstanding, I don’t know, but we have to be very clear: bioplastics are still plastics.
And they are also not to be confused with biodegradable plastics. These will break down naturally with the help of bacteria under the right circumstances.
Not all bioplastics are biodegradable and there are petroleum-based plastics that are biodegradable. So it is important to understand the difference between these two terms.
There is another term that often comes up, compostable plastic. Compostable and biodegradable aren’t the same thing.
If a material is compostable, it means that it will break down into harmless materials, such as soil and water. But in order for something to be classed as compostable, it has to compost within a certain amount of time.
There are two types of compostable: home compostable or industrial compostable. For both the right conditions need to be present, which won’t be there in landfill.
It is not allowed to call a material compostable unless it meets the criteria, and there are labels that tell you if a material is compostable, at home or at an industrial composting facility.
Like with biodegradable, not all bioplastics are compostable and there are traditional plastics that can be composted.
When we speak of bioplastics we speak about plastics that have been made from plant-based sources.
One bioplastic that is used by many eco-friendly brands is cornstarch PLA. Find out more in our guide about PLA.
Are Bioplastics Sustainable?
Let’s get to it: are bioplastics sustainable? At first glance, we can say yes, because they aren’t made from fossil fuels.
However, if we look closer at the topic, we realise that it isn’t as simple as that. First of all, bioplastics don’t have to be made from 100% plant-based sources to be classed as such.
As long as at least 20% of a plastic item is made from plant-based or other renewable materials, it can be classed as bioplastic.
While this is better than fully petroleum-derived plastic, it’s not ideal. And there are more problems.
A study of the University of Pittsburgh has shown that the production of bioplastics is responsible for higher pollution levels.
This is because you have to grow the plants first, which means you need to use fertiliser and pesticides, which are polluting the environment.
And the chemical processes needed to turn biomass into plastic also releases more toxic pollution. So the production of bioplastic is no better for the environment than petroleum-based plastic when it comes to pollution.
However, bioplastics produce quite a bit less greenhouse gas emissions, which is great news.
Another issue with bioplastics is their disposal. While many bioplastics are biodegradable, they need specific conditions, which waste facilities in most countries don’t have.
This means that most bioplastics end up in landfill, where they release methane, a powerful greenhouse gas, when deprived of oxygen.
Even though some bioplastics are technically recyclable, recycling facilities in most countries, including the UK, aren’t able to recycle bioplastics.
Any bioplastic that gets in with traditional plastic will contaminate the whole batch, which means all the plastic will have to be disposed of in landfill.
This means that we would have to have different recycling streams, one for traditional plastic and one for bioplastics. The costs involved would be quite big.
So many of the issues we have with traditional plastic, we also encounter with bioplastics. Producing bioplastics is currently also much more expensive.
However, the price will eventually come down, as better methods to produce bioplastics are found. Another issue is that we would have to start growing the source materials, which would take up a lot of land.
So you can see, the answer to our question “are bioplastics sustainable?” isn’t simple.
Before it can become a sustainable alternative to petroleum-derived plastic, some issues need to be sorted, mostly the disposal and the production processes, which pose the biggest challenge.
