What are bio-plastics?
‘Bioplastics’ has become a catch-all term, incorporating bio-based plastics, biodegradable plastics and compostable plastics. The term itself though does not specify the technical properties of the material in use, or how it behaves or should be disposed of at the end of its life.
Bio- based does not mean bio-degradable
Bio-degradable or compostable refers to how the materials behave in specific environments with conditions allowing it to breakdown. Check out our article that covers these terms in details.
Bio-based plastics refer to the source material, or feedstock, used to make the plastic. For conventional plastics this means fossil fuels (such as oil or shale gas), whereas bio-based plastics are made from biological material (such as animal or plant products). In many cases, bio-based plastics frequently contain a blend of the two.
Land and water usageA complication that can arise regarding the environmental impacts of bio-based plastic is the origin of the feedstock. Half of all the world's habitable land is currently used for agriculture, approximately 51million sq km. Raw material can come from a wide range of crops, such as corn, wheat, potatoes and cassava. A push to scale up bio-based plastics will therefore drive competition for scarce land, leading to deforestation, habitat destruction and undermining the fight for food security and biodiversity protection. This will drive up the corresponding water usage to cultivate this land.
Bio-based plastics are often presented as a more climate-friendly alternative to conventional plastics. Coming from theoretically renewable raw materials, they are assumed to be carbon neutral over their life cycle, as opposed to fossil plastics. Biodegradable bio-based plastics, those that end up in landfill, industrial composting or anaerobic digestors release varying (but significant) amounts of carbon dioxide and methane – a Green House Gas up to 84 times more potent than carbon dioxide – depending on the feedstock.
A lot of challenges with bio-plastic remain
- Ability to degrade in non-specialized environments such as the environment or landfills
- Segregation of waste for these facilities
- Development of these facilities - Less than 20% of waste is treated in India.
- Ability to not-degrade on the shelf and carry liquids
- Land and Carbon Impact of the agricultural produce required
But primarily this does not take use away from the use and throw lifestyle of today. As we consume more and more bio-plastic, the equivalent resources of land, water and agricultural produce will constantly be consumed to create products. Bio plastics will provide a much welcome alternative to where single use packaging is absolutely unavoidable - eg. Garbage bags. But for the rest we should follow the 3 R's in the given order of preference -
Reduce > Reuse > Recycle
University of Bonn (2018) More bioplastics do not necessarily contribute to climate change mitigation: Potential implications of transitioning to plant-based plastics. Science Daily, 7 December [ONLINE] Available at: https://www.sciencedaily.com/releases/2018/12/181207112714.htm
Environmental Defense Fund (n.d.) Methane, the other important greenhouse gas [ONLINE] Available at: https://www. edf.org/climate/methane-other-important-greenhouse-gas