By Anoushka Ghosh, Spring 2025.
Plastics are everywhere. From packaging to pipes, the convenience of this material has made it indispensable to modern living. This convenience, however, comes at a cost– companies refuse to biodegrade, producing harmful and toxic waste over centuries. It is estimated that over 460 million metric tons of plastic were produced in 2024 alone. To put this in perspective, that’s enough disposable water bottles to run around the Earth over 240,000 times. Of this number, less than 10% is recycled, with the majority ending up in landfills, incinerators, or waterbodies. Burning plastics in incinerators releases tons of toxic chemicals into the atmosphere, posing serious health risks including cancer, hormonal disruption, and respiratory illness. It also contributes significantly to greenhouse gas emissions, adding to the effects of climate change In landfills, plastics leach harmful substances into soil and groundwater, while in oceans and waterways, they break into microplastics that enter the food chain—eventually ending up in human bodies. Clearly, plastic waste has serious environmental and health implications and urgently requires action to curb its effects on our societies. Yet despite knowledge of plastic’s harmful legacy, systems meant to manage it—recycling programs, waste sorting, and product design—are simply failing to keep up. Lack of awareness about proper disposal, limited recycling infrastructure, and especially the widespread production and use of complex, non-recyclable and non-biodegradable plastics all contribute to a broken cycle. With so much plastic ending up where it shouldn’t, the question becomes not just how we dispose of it, but how we rethink it altogether. Enter bioplastics– a seemingly sustainable alternative made from renewable sources (unlike the fossil fuels that make up traditional commercial plastics) with promises of biodegradation.
At this point, it becomes important to define what we mean by a “bioplastic,” a term that is easily misunderstood. Bioplastics, or more aptly named bio-based plastics, generally describe polymer materials that are made from a renewable material with common sources being plants like sugarcane and tapioca. These bioplastics can be, but are not necessarily, biodegradable. The appeal of bioplastics as a whole, then, stems largely from the way in which it is manufactured. Bio-based biodegradable bioplastics do exist, however, are they really a feasible alternative to traditional ones?
To assess this, we must first understand exactly what we want to use these bioplastics for. Not all plastics are made equal and each is suited to a different set of uses. Let’s look specifically at the packaging industry, which produces a large amount of plastic waste, and relies largely on soft plastics, specifically Polyethylene Terephthalate (PET), which is soft and easily pliable, yet also durable and heat stable to a high temperature. To replace the widely-used PET, bioplastic would need to be capable of mimicking the properties that make PET the industry standard. That is, it would need to be durable, lightweight, non-reactive, and cheap. Does there exist a bioplastic that can fit these criteria?
One promising bioplastic is polylactic acid (PLA), which is made primarily from cornstarch or sugarcane. PLA is transparent and lightweight, which has allowed it to be commonly used in food containers and disposable glasses. However, it is not as durable as PET, as it begins melting at 60℃, making it unsuitable for the packaging of hot beverages or reheatable meals. PLA can also be composted on an industrial scale (though it wouldn’t compost in your backyard) , which makes it a more sustainable alternative to PET in theory. Still, there are limitations on the practicality of its waste management; since PLA has a melting point significantly lower than PET, it cannot be recycled through the same facilities, as PLA would degrade and become unusable at the relatively high temperatures used to recycle PET. This would require that more recycling plants be built, leading to an undesirable increase in costs associated with the material.
Another kind of bioplastic worth considering is the Polyhydroxyalkanoate family (PHAs), which are made by harmless bacteria that digest sugars. PHAs are produced when these microorganisms are given an excess of carbon dioxide, but do not have access to enough nitrogen, oxygen, or phosphorus, which are all nutrients needed for the microorganism to reproduce. Since the bacteria do not have sufficient nutrients to grow or reproduce, they reserve this excess carbon as granules of PHA, which can then be collected and molded into usable consumer plastics. PHA has garnered specific interest because of their “true biodegradability”- they do not require industrial setups to be composted. Like PLA, they are also thermoplastics (they soften when heated). However, they soften at a much higher temperature, making them much more suitable for a diverse set of uses where heat is a concern (like disposable coffee cups or instant noodle packaging). The problem here, however, is cost. PHAs are expensive to produce, making large-scale adoptions currently unrealistic.
The third contestant is bio-based PET, which, as the name suggests, is chemically identical to traditional PET. Instead of being produced from petroleum (or fossil fuel) based sources, however, bio-based PET is produced from plant-based sources. The ethylene glycol required to make PET in this case comes from crops like sugarcane. Bio-based PET is an attractive choice since it performs just like conventional PET, making it an intuitive replacement. The problem, however, is that this material is still not fully biodegradable. While bio-based PET might limit the use of fossil fuels, it still ends up in landfills and oceans. Additionally, its microplastic components are still toxic. So, while it solves part of the problem, it certainly is not a perfect nor long-term solution.
At this point, we may start to wonder- are there any viable replacements for PET plastics? The short answer: not really. There simply does not exist (currently) a feasible single bioplastic that can realistically take over. While Bio-PET makes economical and structural sense, it simply fails to address the whole problem of waste management. PLA and PHAs are great from an environmental standpoint, but serious steps need to be taken to make them economically feasible. The gap continues to narrow, but an entire replacement is currently unrealistic without investment in both research, as well as facilities to make the adoption of bioplastics plausible.
[1] Jayakumar, A. et al. (2023). Recent progress of bioplastics in their properties, standards, certifications and regulations. Science of the Total Environment, 878, 163156.
[2] Di Bartolo, A. et al. (2021). A Review of Bioplastics and Their Adoption in the Circular Economy. Polymers, 13, 1229.
[3] Rosenboom, J.-G. et al. (2022). Bioplastics for a Circular Economy. Nature Reviews Materials, 7(2), 117–137.