Are bioplastics really biodegradable? | Ask a Scientist

Biodegradable plastics made from plant-based materials... are they the answer? Research scientist Leena Thorat tells us about bioplastics and if they really are biodegradable.
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ON SCREEN:
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ON SCREEN:
Kalina, Host, Ask a Scientist, Environment and Climate Change Canada
KALINA PARISIEN:
Hello everyone and welcome to Ask a Scientist. Plastics are one of the materials we use the most in our everyday lives. Since a lot of these plastics are single use, many of us are turning to eco-friendly alternatives. There is however a type of plastic called bioplastics. On today’s episode, we have a question about these materials that you may all be wondering.
PUBLIC:
Are bio plastics really biodegradable?
KALINA PARISIEN:
Thankfully we have research scientist, Leena Thorat to help explain bio plastics to us.
ON SCREEN:
Leena Thorat, Research Scientist, Environment and Climate Change Canada
LEENA THORAT:
So, it is true that bioplastics are made from bio-based materials, for example, plant-based materials such as wheat, wheat starch in fact, which is converted into plastic. So ideally, we can consider that all bioplastics to be biodegradable and environmentally safe. But that’s not always the case. Did you know that not all bioplastics are bio-based!
We may wonder, what are the problems with bioplastics? You may think that bioplastic items labelled ‘biodegradable’ could be exposed to sunlight, or dumped in water or landfills, and assume these to be safe and responsible ways of discarding them, but that could cause more trouble over time. Not all biodegradable bioplastics can be naturally degraded or broken down by bacteria or other living organisms. Even though they may be labelled biodegradable, they need standard degradation conditions. For example, appropriate temperature, pH, moisture, etc. Which can be achieved in special industrial facilities but currently, very few Canadian cities have the infrastructure needed to deal with them.
On the brighter side, bioplastics are expected to produce fewer greenhouse gas emissions over their lifetime. As compared to traditional fossil fuel-based plastic items. However at this stage, it would be difficult to make concrete claims because bioplastics are relatively new on the market, and we do not have sufficient data telling us about the long-term impacts they may have on humans and environment. In fact, recent studies have suggested that bioplastics could potentially be harmful to ecosystems and could actually contribute more to ozone depletion than traditional plastic items.
Currently bioplastics are being used in disposable items like packaging, bottles, phone casings, 3D printing, etc. And whether these are safer alternatives to tackle global plastic pollution is still a question we need to investigate.
Researchers have been testing how natural, as well as engineered bacteria, can be used to completely and naturally degrade plastic material. Hopefully we will have an answer soon.
KALINA PARISIEN:
Thanks Leena.
So, even though a label might state that an item is “biodegradable”, it may take very special conditions for that item to break down, and it may not be compostable in your city compost bin, or your backyard.
Stay informed and keep sending your questions to us here at, Ask a Scientist.
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