A dictionary definition of the term 'biodegradable' would be “capable of being decomposed by bacteria or other biological means.” However, different governments around the world use slightly different definitions to inform and enforce the limited legislation there is around using this terminology.
The EU states “'Biodegradation' is a process by which material disintegrates and is decomposed by microorganisms into elements that are found in nature, such as CO2, water and biomass.”
The lines are blurry, and there is a key distinction to be made between biodegradability, and compostability, which we will cover separately. There is also no time element given in most definitions of ‘biodegradable’, rendering the term slightly useless anyway. Wood is ‘biodegradable’ but we’ve been building long-lasting structures out of it for centuries.
Given the lack of legislation in this area, it seems the boundaries of ‘biodegradability’ have been stretched, to put it lightly. We see claims of biodegradable plastics, which make no sense to us. In the ocean, UV rays break down the physical structure of plastic, turning them into ever smaller pieces, the ubiquitous ‘microplastics’ you may have heard of. Even when they do degrade on a more chemical level, research shows that many plastics degrade into hazardous chemicals such as BPA (more on that in our glossary (link)), PS oligomer (suspected carcinogen and hazardous to marine environments) and other Estrogenically Active (EA) chemicals. These are certainly not found in natural eco-systems. Furthermore, as no standard exists, there is often confusion over where/how materials will degrade. Some that will break down in soil will not do so in a marine (saltwater) environment and vice versa, so as a consumer, it’s really difficult to be sure!
So, if plastic is not biodegradable, what about products made from natural materials mixed with plastic resins?
Many products on the market mix natural fibres or mulches, from seemingly excellent sources such as bamboo, rice husk, and even used coffee grounds, with binding agents. We were doing so well until the last part! These binding agents range from melamine-formaldehyde resin, to polypropylene, acting as a kind of glue to hold the fibres or particles together, creating your cup or bowl, and making sure liquid doesn’t seep through the semi-permeable make-up of the material. Can these claim to be biodegradable? Well, the answer has to be no, doesn’t it? You can’t easily extract or split the substances, so if you break the product into pieces and bury the shards, as some disposal guides recommend, won’t this simply introduce melamine-formaldehyde resin or polypropylene into your soil or compost heap? Or into the digestive system of worms and other creatures? Again, the remnants of the degradation of these consumer products does not meet the EU definition above, as it leaves behind elements that are not found in nature.
What about oxo-degradable plastics?
You may have heard of these in recent times. In simple terms, they are traditional plastics with an additive which accelerates the breakdown of the plastic. In practise, this means more microplastics, quicker. Thankfully, the EU has already moved to restrict the use of oxo-degradable plastics, and we look forward to this being rolled out.
So… sounds like biodegradable products should be avoided?
Well, we think consumers should certainly be careful, in the absence of concise legislation, of what they are using, and crucially, how they are throwing it away. So-called biodegradable alternatives can actually contaminate traditional waste streams if not correctly disposed of. There is a strong argument to suggest that swapping plastics to even compostable alternatives doesn’t get to the root of the problem. To live within the planet’s means, we must break the habit of single-use. Creating products which are simply designed to be thrown away, albeit in a slightly different manner, without the correct infrastructure, perpetuate this habit.