In recent years, bioplastics have emerged as alternatives to conventional plastic products, seeking to curb the substantial negative environmental repercussions resulting from plastic production and waste. Traditional plastics, which have been mass-produced for over half a century, can be found everywhere: in food packaging, medical equipment, clothes, wet wipes, even tiny microscopic plastic particles contained in makeup. Unfortunately, this increase in plastic production has not been met with an increase inadequate recycling protocols, laws, or facilities, which are still lacking across the country. In fact, 91% of plastic doesn't get recycled. While there is no shortage of plastic in our everyday lives, the process of waste disposal, recycling, and composting is getting ever more complicated.
This is where bioplastics come in. Bioplastics (or biobased plastics) is an umbrella term encompassing both biodegradable and compostable plastics. From the outside, biodegradable and compostable plastics seem like the perfect solution to our growing plastic problem. Yet bioplastics come with their own unique set of issues in regards to sustainability.
What’s the difference between biodegradable and compostable plastics?
An important distinction to note is that not all biodegradable plastics are compostable. Unlike conventional plastic, which remains relatively stable for hundreds of years, biodegradable plastics can break down in a process involving microorganisms. In this process, polymer-consuming microbes transform biodegradable plastic containing polymers into water, carbon dioxide, and plant matter; for a more in-depth review of the process, see this source. However, some biodegradable plastics are made of petroleum or fossil-based sources and can also contain toxic additives that are released upon breakdown. Compostable plastics, on the other hand, are derived from a renewable resource (such as starches) and can be turned into biomass, water, and carbon dioxide. Compostable plastics do not contain any toxic materials.
Issues with bioplastic disposal
Bioplastics (both compostable and biodegradable) cannot degrade in a landfill, or when mixed with recycling. Instead, these plant-derived plastics need to be industrially composted (and can only rarely be home-composted). In an industrial composting facility, bioplastics will degrade much more quickly than in an at-home composting environment, mainly due to the equipment and procedures available and utilized at the facilities themselves.
This complicates the process of disposing of bioplastics, and leads to landfill waste or incorrect disposal into the recycling bin, which, in turn, contaminates the recycling system. To make sure your state or county has an industrial composting facility, it is best to check with the city directly. Davis Recology and other compost facility locators like this one also provide great resources.
Labeling issues and bioplastic misuse
As an alternative to conventional plastic products, biodegradable plastics have been widely acknowledged for their environmental benefits. In light of this, many companies will unfortunately label their products as “biodegradable” or “compostable,” even if this is not the case. A form of greenwashing, this mislabeling puts companies in a better light and makes them appear – falsely – environmentally friendly. To prevent this from happening, countries like the USA have implemented industry standards that label bioplastics as compostable. The certification from ASTM International (formerly known as American Society for Testing and Materials), for example, can specify whether a compostable plastic product needs to be industrially composted or whether it can also be composted at home.
