Know what you are buying.

Most people would probably agree that making a change to better the environment is a good thing, be it at home, work or wherever. Cynically though, as people have started moving away from harmful products like single-use plastic, others have moved in to try and sell them the same old rope; hence the term ‘greenwashing’. The issue commonly lies in which products to buy and what all these terms mean. Do they biodegrade? But they are made from plant matter! Here we go over a quick guide to help give you some important information when making your ‘green’ purchases.

First off we have to understand how plastic is made so we can appreciate why the other products either don’t work or why they continue to be so harmful. Plastics are made from long chains of hydrogen and carbon linked together; for our purposes imagine yellow Lego bricks stacked up on top of each other. A single brick is a monomer and as we keep adding a new brick we make sure we cement it with superglue. After adding a number of bricks in this fashion we end up with… plastic! As we have superglued the bricks together, taking it apart again is really quite a problem and this illustratively describes why plastic does not break down naturally in the environment by bacteria.

Degradable plastic

Most of our plastic fits into this category. Degradable plastic simply means that it can be broken down into tiny pieces through manual or environmental processes and it is presumed that eventually it disappears. This issue with this is that some research out there suggests that plastic simply breaks down into micro plastic and can still enter the food web. Further, if you continuously divide by two you will approach zero in smaller and smaller increments, but never actually reach it. The evidence suggests that this is what is happening with degradable plastic today.

Biodegradable plastic

The issue here is that we take our single yellow brick and every, say, five bricks add a red one which isn’t superglued – then we continue to add yellows which are. The red brick represents molecules of iron or zinc which bacteria can attack to break down the long chain. As they are not superglued together this does indeed work, for the red/yellow brick joint at least. Et voilà, biodegradable plastic! The frequency of the red brick determines if you end up with plastic or not. Add too many red bricks and you end up with useless gloop. Either way, we are still left with the long chain of yellow bricks which do not break down and thus still left with a problem.

Compostable plastic

Rather than yellow bricks, which represent hydrogen and carbon, now we have a blue brick made from 50% organic material, typically. These blue bricks can be broken down, hence their composability, but only under certain conditions. These conditions can vary by manufacturer but typically they require an industrial compost heap and the plastic needs to be between 50-140oC. As I am sure is obvious, if this type of plastic makes it into our rivers or oceans then the only place it stands a chance of reaching that temperature is as you approach a hydrothermal vent and consequently is as detrimental as the normal stuff.

Bioplastic from plant matter

Sounds great right? It isn’t! Plastic is typically derived from crude oil in order to make the yellow bricks in our example. All bioplastic does is obtain the hydrogen and carbon required to make the yellow brick from plant matter. Sure, there is a positive because we are no longer requiring oil as the raw material, but the end result is normal plastic. What is true is that some of these products cleverly interlink with either the biodegradable or compostable industry standard which really makes the greenwashing case. However, as explained above with compostable plastic, these do not perform as one expects, and for the same reasons these products fail too.

Latest research on our plastic problem

This year (2018) some promising research was published in the journal Proceedings of the National Academy of Sciences which demonstrated that a UK University had accidentally created a mutant enzyme which can break down plastic in a matter of days. Promising indeed especially from a recycling point of view. In theory, plastic waste which has been collected at the local refuse heap could be exposed to this enzyme and be completely broken down. This would free up space for more plastic and so on. But however promising this research may be, what about the plastic which has not yet been consumed? Ponder for a moment on all the plastic which has already ended up in our oceans and how we could remove this. A massive undertaking indeed, to say nothing for the potential environmental impact should the artificially created bacteria break out of their laboratory prison.

Although some of the latest research leaves us room to hope, the reality of some of these solutions are still a way off. Further, some of their potential biological impacts are hardly worth considering. Therefore, the best advice that one can give when trying to determine if the plastic is eco-friendly is, if it looks like plastic and feels like plastic then it is plastic, regardless of the fancy marketing. So simply refuse plastic, for now at least.