Updated: Nov 25, 2020
It today’s iteration of “where does our waste go” let’s talk about bioplastics. We’re going to dive into what they are made of, how they are disposed of, and then talk about if they are really better than plastic.
The inspiration for this series lies behind all the plastic pollution I saw here on the shores of Okinawa. It made me think, “where does our waste go after we put it in our blue bins and why does so much end up in the ocean?” Since then, we have explored plastic (video/blog post), glass (video/blog post), metal (video/blog post), paper (video/blog post), and e-waste (video/blog post). I’d like to keep this series going so let me know which material you’d like me to explore next!
What are bioplastics made of?
Bioplastics are a type of plastic that are made from natural resources like vegetable oils and starches as opposed to crude oil. Because of this, the consumption of petroleum will go down and the desire to create and use bioplastics has gone up. It’s always great to cut back on our use and reliance of fossil fuels. Bioplastics market is operating currently at a growth of 10% annually meaning that bioplastics accounted for around 10-15% of the plastic market in 2016 but was predicted to reach about 25-30% this year. In fact, it’s becoming so popular that the market this year is around $17 billion and is expected to grow to $44 billion in just two years.
Looking forward, researchers are trying to find alternative ways to create bioplastics utilizing our waste instead of brand new plants. Kartik Chandran students of and Colombia are developing ways to make bioplastics from wastewater and solid waste. Chandran found a way to create them using acids found in things like vinegar. You can read more about his method here.
Another alternative is from a company called Full Cycle Bioplastics in California who create PHA from organic waste instead of virgin plants. They use food waste, crop residue like stalks and leaves, garden water, and even unrecycled paper. This PHA is used to make traditional single-use plastics and is compostable, marine degradable (meaning if it ends up in the ocean it can serve as bacteria food).
There are a whole slew of other companies creating bioplastics from things other than virgin plants. They use things like grasses, wood scraps, algae, methane, sugars, and so forth. You can read more about them here.
How are bioplastics made?
Bioplastics are polymers that are produced within bacteria. The bacteria produce polymers once a source of carbon is added in excess and at least one other nutrient/material is added. The bacteria use sugar from plants to fuel the cellular process to create a polymer. The polymer is then extracted and dried to be turned into bioplastic. You can read more here.
A perk of bioplastics from the beginning of its life cycle is that it is made with renewable biocarbon. And, of course, it is great to be less and less reliant on fossil fuels.
Types of bioplastics
First we have PLA: Polylactic Acid. This is a very common type of bioplastic that is derived from vegetable fats/oils, cornstarch, tapioca, microbiota, or other resources. It is a transparent plastic that can be molded, turned into films or sheets, and can even be spun or 3-D printed. The best part is that PLA can degrade in soil or sunlight. But, a downside is that it is only stable up to 110F meaning it cannot be used for food purposes.
Next is PHA: Polyhydroxyalkanoate. This is made from microorganisms that are sometimes genetically engineered and they produce plastic from organic materials. The microbes are deprived of things like nitrogen, oxygen, and phosphorus, but given high levels of carbon instead. As a result, PHA is produced as carbon reserves which are stored in granules. This PHA is then harvested and has a similar chemical structure to that of traditional plastics. PHA is also biodegradable meaning it won’t cause harm to living tissue so PHA is often used in the medical field and single-use food packaging.
Lifecycle photo: https://www.european-bioplastics.org/bioplastics/environment/
Let’s get some terms straight: Degradable vs biodegradable vs compostable
Degradable – All plastic is degradable, even traditional plastic, but just because it can be broken down into tiny fragments or powder does not mean the materials will ever return to nature. Some additives to traditional plastics make them degrade more quickly. Photodegradable plastic breaks down more readily in sunlight; oxo-degradable plastic disintegrates more quickly when exposed to heat and light.
Biodegradable – Biodegradable plastic can be broken down completely into water, carbon dioxide and compost by microorganisms under the right conditions. “Biodegradable” implies that the decomposition happens in weeks to months. Bioplastics that don’t biodegrade that quickly are called “durable,” and some bioplastics made from biomass that cannot easily be broken down by microorganisms are considered non-biodegradable.
Compostable – Compostable plastic will biodegrade in a compost site. Microorganisms break it down into carbon dioxide, water, inorganic compounds and biomass at the same rate as other organic materials in the compost pile, leaving no toxic residue.
The elephant in the room...are they even better than plastic?
In the plastic video/blog post, we learned that plastic is infiltrating our oceans, is difficult to recycle, is expensive to recycle, and only 9% has EVER been recycled. The bottom line, plastic isn’t great. Obviously, bioplastics are great in the sense that they are made from plants and not petroleum...but is this significantly better or just a small step up?
First, single-use is never good
It is never good to spend time, money, energy, and resources for a material to be used for a few seconds or minutes and then thrown out, or even recycled or composted. Ideally, multi-use is best.
Second, land use and pollution
This study compared seven traditional plastics, four bioplastics, and one hybrid plastic. The researchers found that bioplastics production actually can create more pollution due to fertilizers and pesticides in crop production. Obviously, more crops also means more land-use, too which has the potential to lead to deforestation and monocultures, two topics I will dive into in the future. For the ever-growing market of bioplastics, experts agree that it would require more than 3.4 million acres of land which is larger than Belgium, the Netherlands, and Denmark combined. And then you have to factor in running the machinery.
What about using plants for food instead?
This is up for debate, too. Our world is scarce on food, yes, but is making food-based plastic causing food shortages? Maybe, but probably not. I’m not going to dive too far into it here, I want to do that another day, but briefly, most of the corn and soy production in the world goes to feeding cattle. So, simply put, eating less meat or going vegan can help food scarcity as well. Especially since bioplastic production is still so low, I don’t think we can put all the blame on bioplastics. Yes, we need to use less plastic in general, but we collectively also need to eat less meat. Both will help fight food scarcity. Again, I will talk about this later, but for now, let’s focus on bioplastics.
But, bioplastics produce less greenhouse gases
Clearly, there are fewer greenhouse gases during creation since it’s not made of petroleum. This study determined that the US could cut greenhouse gas emissions by 25% just by switching all plastics to bioplastics. And this was conducted on bioplastics made with fossil fuels. If bioplastics were created using renewable energy, that number would be even higher. When an item is composted they return the carbon to the plants sucked up while growing instead of releasing that carbon that had been previously trapped underground in the form of oil.
They’re compostable, yes, but how often are they even composted?
I could almost guarantee that most people don’t even know if their region has a composting facility let alone use it. This means that your bioplastics probably just go to landfill. When sent to landfill, materials are oxygen deprived. Even your banana peels won’t break down properly in landfill. The same goes for bioplastics; they might release methane when deprived of oxygen which is 23 times more potent than CO2.
Establishments will need to start offering compost
We can’t continue to worship bioplastics and just throw them in the landfill. Restaurants, schools, cafes, and so forth will need to start offering compost bins right alongside their trash and recycling bins so that bioplastics can be disposed of correctly and not get turned into methane and never break down. Like I already said, we can’t continue to praise bioplastics for being so great but not allow them to achieve their full potential.
But, don’t put your bioplastics in recycling with regular plastics
This can lead to contamination. If you’ve been here a while, you know I love talking about contamination. Contaminated recycled will end up in the landfill. If a piece of bioplastic ends up in a batch of plastic recycling, it can all be ruined.
The cost of bioplastics
PLA can end up costing 20-50% more than other plastics because of the extensive process to turn plants into the building blocks for PLA. But, as they increase in popularity and researchers are finding new ways to create them, they are becoming cheaper. So, if you like using bioplastics, use them and support the market to show a demand for them!
At least they break down
Though, if they do end up in the ocean or as litter, they will at least eventually break down, unlike their petroleum counterpart. Obviously, litter is terrible, but litter that breaks down into nothing is better than litter than breaks down into microplastics that never truly disappear. Of course, do your part to dispose of bioplastics properly and pick-up litter when you see it!
Another pro to bioplastics is that contamination is not an issue
With recycling, contamination becomes a real issue in the process like we learned with plastic, glass, metal, and paper. But, if you have a bioplastic wrapper with a bit of tomato sauce on it, for example, you don’t have to rinse it before throwing the whole thing into the compost. Though, there are a few rules when it comes to compost that I talked about in this video that I talked about in this video, but for a general rule of thumb, you can stick to no animal products in your compost!
The question still remains...should I use bioplastics?
If the question is bioplastics vs petroleum-based plastic, absolutely. If the question is bioplastic vs another material or unpackaged, go for the latter. Bioplastics isn’t the solution. We are still too reliant on plastic and we need to break that cycle for a few reasons. The world is not perfect about recycling petroleum-based plastic and the world is still not set up to compost that much bio-based plastic. So, the perfect in between is to consume less plastic. I think if you only have the choice between the two, pick bioplastic and hold onto it until you have a compost bin or take it home and do it yourself. But, avoid all plastic items if you can. Don’t just buy bioplastics because it’s trendy and don’t just buy them to support the market.
Don’t get me wrong, bioplastics are a great alternative and there are a lot of pros to them, but it’s still plastic and it still has it’s cons. Like I said toward the beginning, all single-use items are not ideal and should be avoided when possible. But, don’t praise bioplastics for being the best material of them all. Scientists are working to make more and more bioplastics from other materials that are less and less harsh on our air and land and water and life so keep and eye out for those and use those when they become available.
Thank you for reading along. I appreciate your time and appreciate you coming along to learn more. Until next time, remember that the small changes you make have a big impact in the long run :)