Have you ever felt confused by the terms “biodegradable” and “compostable”? Did you ever buy such a product thinking “it must be good for the environment”? The choice in eco-products is expanding by the day and with the misuse of labels such as ‘bio’ and ‘eco’, navigating the maze of environmentally friendly product is becoming increasingly difficult.
So, let’s dig into one of the common frustrations when contemplating to buy biodegradable and compostable products. Should we buy them? Do they actually pose a less negative threat to our environment? – and how are the two different?
Recently a small company owner shared with me “how proud they were” to now deliver their product in biodegradable packets. He also shared that these packets will biodegrade in 2 years and were 3 times more expensive than the regular bubble packets. Coming from a scientific background, I was, of course, curious to know how this actually worked in practice. I asked about the conditions under which the packet is biodegradable and where they were being collected for the purpose of biodegradation? The reply was somewhat disheartening, but most probably not uncommon:
“I don’t know, I suggest you just put the packaging in a regular rubbish bin”?
Plastic bags to the test
With this multitude of new products popping up labelled “biodegradable” and “compostable”, businesses and consumers are understandably becoming increasingly confused. What do these terms actually mean, and more importantly, how do the processes work and are they relevant to the current state of infrastructure available in your area?
Biodegradable plastic suggests that we are dealing with a material that would degrade to little or nothing over a period of time and therefore having a lesser negative impact on the environment. However, a recent study has disproved this theory. The authors tested compostable, biodegradable, oxo-biodegradable, and conventional polyethene plastic bags and placed them in three different natural environments: the ground, outdoors (exposed to air and sunlight), and in the sea. In all of the environments, not one of the bags degraded completely, and noticeably, the biodegradable bag left in the sea and in the soil was practically intact – so much so that it could hold 2 kgs. of goods.
When is biodegradable degraded?
Testing is obviously a convincing indicator, but let me summarize some facts, and hopefully, I’ll be able to provide a framework and definitions so you as the consumer will be more critical when confronted with a label and enable you to ask yourself whether or not buying this will make a positive difference to the environment.
The European Standard EN 13432 and the US standard ASTM D6400-99 provide criteria for what can or cannot be labelled as compostable and biodegradable, ensuring that the materials will break down under well-controlled industrial composting settings. Compostable claims for packaging should be verified by a third party certification and t is misleading for manufacturers to merely claim biodegradability without providing a standard specification.
Compostable product is a product that will decompose either through the action of naturally occurring micro-organisms (bacteria and fungi) or in a professionally managed composting facility, under strictly controlled conditions (such as heat and moisture). This occurs within a set time frame and turns into decayed organic matter that will form compost rich in nutrients. Composting process leaves no contaminants or toxic residue/substances.
Here, it’s important to note that where compostable is certainly biodegradable, biodegradable is not necessarily compostable.
Biodegradable refers to a product capable of being decomposed by bacteria or other living organisms such as fungi. The process of biodegradation occurs in three stages: biodeterioration, biofragmentation, and assimilation and requires certain conditions for each of the stages to occur. It’s important to remember that everything will biodegrade at some point in time – paper, clothes, certain plastics, glass, wood, etc. When there are no defined time limits for the term biodegradable it becomes a confusing statement.
While biodegradable is associated with environmentally friendly products, it is not necessarily the case. The reason is that different stages of the process produce fragments of different sizes. By splitting into fragments in the natural environment, chances are high it will reach waterways or will get picked up and absorbed by animals. Biodegradable plastic could still be made from oil with some additives that speed up its degradation, but could still take years to fully biodegrade.
Oxo-biodegradable – better or worse?
In the case of “oxo-biodegradable” packaging, european-bioplastics.org specifically states that ‘Oxo-fragmentation’ does not mean biodegradation:
“Plastics that are advertised as being ‘oxo-degradable‘ or ‘oxo-biodegradable’ are made from conventional plastics and mixed with additives in order to mimic biodegradation. However, the main effect of oxidation is a mere fragmentation of the material or product into small particles that remain in the environment. These products do not comply with the standards for compostability and are not considered bioplastics.”
Not only are these materials not suitable for a composting facility, but they also not suitable for recycling stream either because of potential contamination.
In Singapore non-recyclable waste is incinerated with the ash being transferred to our landfill at Semakau island. Singapore – as of the moment of writing – has no composting/biodegradation facility and presently there are no plans to introduce such a facility.
It is therefore not enough to purchase a product that has the potential to be composted or biodegraded. If there is no way to realize this potential – if your region, town or neighbourhood don’t have a composting facility – then purchasing a compostable packaging does very little to reduce waste. That being said, it is good to know that the environmental impact of a compostable product is lower than the one made from fossil fuels (based on LCA studies), even if both will eventually be incinerated.
The bottom line is that consumers are responsible to properly dispose of the product according to the requirements for compostability/biodegradability and recyclability. Your conscious might be cleaner for buying compostable or biodegradable – the question is whether your local environment will be! So make sure to do your homework to understand what happens to the product you are buying, so you can save your efforts and pennies and put it where it matters.