If you’re hoping to find out about a wonderful material that has the qualities of plastic but leaves no traces on the environment, we may be about to disappoint you. Unfortunately, there is no such material—any plastic will behave like plastic at the end of its lifecycle. So, the best thing you can do is to avoid all plastics (especially single-use), no matter how green its label is! But seeing as many people confuse “bioplastic” as a nature-friendly replacement for conventional plastic, let’s look into this topic in a bit more detail.
The “bio” in plastic-related terminology can be misleading when you’re trying to choose more eco-friendly options. Which is exactly what happens with the word “bioplastic”. In fact, officially there is no such term, but “bio-based” or “biodegradable plastic” (or indeed both) is what is often meant by this. However, no bioplastics are a flawless eco-friendly substitute for conventional plastic, and each type of bioplastic needs to be treated differently after use. Otherwise, they simply add to the plastic pollution problem. Which is why we always advise avoiding the word “bioplastic” entirely, and using the more accurate terms shown below. (By the way, you won’t find oxo-degradable plastic in this list. Our previous article will give you a clue as to why).
When looking at the source of plastics, we find they are either bio-based or fossil fuel-based. In bio-based plastic, the fossil fuel source is replaced with a biological one (such as corn, sugarcane, avocado, etc). So, the fact that a plastic product is bio-based does not necessarily mean the product is biodegradable or compostable. In fact, less than 40% of bio-based plastics are produced to biodegrade.
Moreover, such plastic will often be mix-sourced and producers are not obliged to state the amount of bio-based material. Some packaging that producers call “green” is made of only 20 percent plant-based material (while the other 80 percent is fossil fuel-based). This leads to misconceptions among consumers thinking they are buying eco-friendly products. For example, bio-based PET is chemically identical to fuel-based PET. The difference is only found in the source from which ethylene glycol is derived (while the other part of PET, terephthalic acid (TPA), is still petroleum-based).
Some bio-based plastics can be recycled with traditional recyclables as they are chemically identical to PET or PP made from fossil materials. However, many are not currently accepted in curbside recycling schemes as they could potentially contaminate traditional plastic recycling.
Just like plastic made from fossil fuels, bio-based plastic doesn't decompose in landfills. Moreover, any plastic, including bio-based, when mixed with other solid waste cuts off access to oxygen for organic waste, preventing it from decomposing. As a result, organics release methane, which comprises 4% of the global greenhouse gases causing climate change, and has a particularly potent greenhouse effect.
It takes hundreds of years for plastic to be broken down into smaller and smaller pieces, but they will never degrade fully into hydrogen, oxygen and carbon. Plastic’s chemical bonds are so strong that they continue their existence in the form of microplastics. Modern landfills prevent microplastics and toxic chemicals from leaking into the environment, but in the majority of landfills such a system either doesn’t exist or isn’t fully functioning. And of course, there is no barrier to microplastics when plastics are strewn in our forests, parks and beaches. Thus, microplastics and other hazardous elements enter into the groundwater and pollute the soil, drinking water, rivers and seas.
There is one more problem with bio-based plastic that is less discussed, but equally as important as the others. We literally don't have enough land in our food-scarce world to grow plants for plastic. Land is a limited resource and we already have a strain on arable land to grow food. As the global population continues to grow, along with the demand for food, it is quite clear for what use we should prioritise available land.
The term biodegradable plastic explains the material’s end-of-life behaviour. Such plastic decomposes with help from living organisms, usually microbes, which break it down into water, carbon dioxide, and biomass. But this only happens in controlled conditions such as wastewater treatment plants or composting plants.
Biodegradable plastic will not degrade in the open environment. And even if, hypothetically, it could, plastic items may bring death to wildlife in forests or seas during this time (as we are talking about months and years, not days or weeks, that it would take to break down). Microplastic hazards also can’t be discounted, as the fragmentation of biodegradable polymers leads to microplastics as well.
Compostable plastic does not compost in landfills, the open environment or soil! This is because compostable plastic is primarily designed to decompose under specific conditions (60-70 degrees Celsius is a basic requirement) in industrial composting plants.
Very few plastics are designed to degrade in a home composter. A thin plastic bag will decompose in a well-managed home composter with a temperature of 20-60 degrees and enough fungi and bacteria to support the process for at least 1 year. And seeing as these conditions often vary in home composters, it can take much longer.
No, they aren’t. When it comes to bio-based plastics, it is true that they are made mostly from plants (though sometimes animal products are used as well), so they are relatively carbon-neutral as plants absorb CO2 while growing. But their production often relies on chemical-intensive industrial agriculture. And in cases where they are not returned to the economic circle through recycling or biodegrading according to their design, they contribute to plastic pollution.
Biodegradable and compostable plastics are not always a more eco-friendly choice either. They need special conditions to decompose, which are not widely available. Even if there is a composting facility in your region, they may not accept compostable plastic because they cannot provide the necessary heat, humidity and UV light conditions. Besides, when buried in the landfills, such plastic releases methane and becomes even worse than regular plastic.
And what is equally important to note, is that a huge variety of plastics can confuse consumers. As a result, they may put the wrong packaging into the wrong bin—cancelling out all the benefits of biodegradable or compostable plastic. Moreover, biodegradable plastic can jeopardise the recycling process. Such plastic can’t be recycled because it will contaminate the whole batch and reduce the quality of conventional plastic.
Even plastic standardisation and related legislation doesn’t help. They too have their flaws, as they add further confusion to the bio-based and biodegradable plastics issue. It’s important to understand that eco-labels (like the ones we’ve seen above) are assigned to a plastic product or packaging following laboratory tests, as it is difficult to reproduce real-life conditions in assessments. Many NGOs and eco-activists are working to make standardisation more transparent, and make the legislation work for the environment.
And finally, if we continue designing single-use plastic items—only changing the source of the material or its end-of-life behaviour—then we don’t bring the circular economy any closer. Overconsuming doesn’t disappear, and the waste problem is still with us.
As you can see, just replacing conventional plastic with bio-based and biodegradable ones won’t fix all our environmental problems. We must produce less, promote less, use less and chuck out less of all kinds of plastic to reduce plastic pollution. Because the best type of plastic is the one that is not produced.