Bioplastics and Biodegradable Plastics: Are They Different?
Updated: May 5, 2021
Have you ever wondered what the difference between bioplastics and biodegradable plastics are? Did you maybe assume that they were the same thing? More often than not, most people don’t realize that there is actually a significant difference between the two and how different and yet also similar these plastics are to regular plastics. The presence of the prefix “bio” also often leads people to believe that bioplastics and biodegradable plastics are environmentally friendly and much better alternatives to regular plastics, though in reality, the situation is much more complex than that. This blog post will explain just what bioplastics and biodegradable plastics are, what their similarities and differences are, and how eco-conscious they really are compared to regular plastics.
What Are Bioplastics and Biodegradable Plastics?
In order to understand the differences between the three plastics, we should first explain what regular plastics are made of. All plastics are made of chains of molecules linked together, which are referred to as polymers in chemistry. Regular plastics, like the kinds of plastic used to make garbage bags, grocery shopping bags, and plastic straws, are made from carbon polymers sourced from oil, natural gas, petroleum, or crude oil, which are non-renewable sources and take centuries to break down in the environment.
Now how do bioplastics and biodegradable plastics differ? Bioplastics source their polymers from natural materials such as corn starch, cassava starch, or seaweed, which means the materials they eventually put back into the environment are less harmful compared to regular plastics. Biodegradable plastics, on the other hand, still source their polymers from non-renewable sources like regular plastics, with the difference being that during the production process, biodegradable plastics are given additives that make them break down more easily in the environment, especially when exposed to sunlight, oxygen, moisture, and heat.
What Are the Pros and Cons of These Alternatives?
Now that we’ve explained the fundamental differences between each of these plastic types, what are the benefits and pitfalls of each one?
Energy Consumption During the Production Process
Bioplastics take the win in this category, as they generally take less energy to produce compared to their regular and biodegradable counterparts. Polylactide acid (PLA), for example, saves ⅔ of the energy needed to make its regular plastic counterpart even though it is almost indistinguishable from plastics like polyethylene and polypropylene.
Carbon Dioxide Footprint
Bioplastics supposedly have a smaller carbon footprint compared to the rest as the carbon dioxide produced when the bioplastics break down is roughly equivalent to the amount of carbon dioxide absorbed by the plants used to make these bioplastics, and they produce 70% less greenhouse gases compared to their regular counterparts when degrading in landfills. But there are also some caveats to this situation. For one, there is an opportunity cost associated with using plantations to plant crops for bioplastics as opposed to human consumption, which results in the fall of food supply and subsequent rising of food prices, negatively impacting those in poverty. Growing crops to create bioplastics also comes with the negative environmental impacts of agriculture, which include greenhouse gases, water pollution, and chemical fertilizers from the corresponding plantations. As for biodegradable plastics, they are not much better than bioplastics either. When biodegradable plastics decompose, some of them release methane gas in the process, which is a greenhouse gas, meaning that biodegradable plastics can be potential contributors to global warming.
Compostability and Reusability
Bioplastics are, for the most part, compostable, in the sense that when they break down, all the materials used to make bioplastics will blend back into the environment harmlessly. But, this doesn’t mean that they can readily compost in your backyard. The catch is that some types of bioplastics require certain composting conditions, such as ultraviolet light, high temperatures, industrial composting sites, or bioreactor landfills in order to properly break down. This means that if they end up in regular landfills or are buried in your backyard, they won’t necessarily break down and may still end up contributing to the growing landfills in your area. Additionally, bioplastics are also not the easiest plastics to recycle, as they need to be processed in different ways compared to their regular counterparts. This means that if bioplastics and regular plastics are recycled together, it can be very difficult to tell the difference between the two and the entire collection might just be thrown out into landfills instead of getting recycled!
Biodegradable plastics are even more concerning than bioplastics. Seeing as they are still made from petroleum-based polymers, they will still be leaving microplastics and toxins in the environment, despite their accelerated degradation timeline. This means that their impact is almost similar to that of regular plastics, with the only difference being that they break down into micro-fragments more easily than the regular counterparts. They also might not break down at all if the conditions at the landfills don’t meet the aforementioned conditions needed for these biodegradable plastics to break down like light, moisture, heat, or oxygen. Considering that plastics in landfills are often piled up on top of each other with other types of trash, the chances that the correct conditions are met at a landfill are quite slim.
So as we can see, bioplastics and biodegradable plastics aren’t all that the marketing industry has led us to believe. While they undoubtedly have the potential to be more environmentally friendly compared to the regular plastics, without proper conditions and treatment, their impact on the environment once disposed of can be just as harmful as regular plastics. With that in mind, this example is just one of the many that highlight how important it is to do research on the products you’re using and a call to make sure that you look beyond the “eco-friendly” and “biodegradable” labels to make sure that the choices you’re making are in line with your values. So, if you’re interested in learning more about warning signs to watch out for in “sustainable” items, ways to check whether your products are actually eco-friendly, or just want to learn more about environmentalism and sustainability in general, be sure to subscribe to our newsletter, stay tuned for more blog posts, and follow us on Instagram @wellmadewrld !