Only about 9% of plastics get recycled, much of the rest pollutes the environment (9 million tons enters our oceans each year) or sits in landfills, where it can take up to 500 years to decompose while leaching toxic chemicals into the ground.
Plastics made from 20% or more renewable sources are often called bioplastics. They are made from renewable sources such as Corn, Bean, Sugar Cane, Vegetable Oil etc.
They are a great substitute to traditional plastics that are made from fossil fuels because Crude Oil does not regenerate. Bioplastics also generate a smaller carbon footprint, have faster decomposition, are less toxic and does not contain bisphenol A (BPA), a hormone disrupter that is often found in traditional plastics.
However, it turns out that bioplastics is not the magic solution to our plastic problem after all.
First... lets go through some often misundertood terms:
All plastics are degradable. With enough time everything degrades. Different types of plastic disintegrates in different speed under different conditions. Regular plastic take many centuries to degrade.
Biodegradable plastic can be broken down by microorganisms under the right conditions. It also requires industrial composts that uses high temperatures for the process.
Compostable plastic will biodegrade in a compost site. Microorganisms break it down at the same rate as other organic materials in the compost pile, leaving no toxic residue.
The main type of bioplastic today is called PLAPLA (polylactic acid) is typically made from the sugars in corn starch, bean, vegetable oil, cassava or sugarcane. It is biodegradable, carbon-neutral and edible. It is not compostable.
The side effects of productionStudies has determined that bioplastics production results in greater amounts of pollutants, due to the fertilizers and pesticides used in growing the crops and the chemical processing needed to turn organic material into plastic. The bioplastics also contributed more to ozone depletion than the traditional plastics, and required extensive land use.
Although, bioplastics do produce significantly fewer greenhouse gas emissions than traditional plastics over their lifetime. Also, there is no net increase in carbon dioxide when they break down because the plants that bioplastics are made from absorbed that same amount of carbon dioxide as they grew.
While the biodegradability of bioplastics is an advantage, most need high temperature industrial composting facilities to break down and very few cities have the infrastructure needed to deal with them. As a result, bioplastics often end up in landfills where, deprived of oxygen, they may release methane, a greenhouse gas 23 times more potent than carbon dioxide.
When bioplastics are not discarded properly, they can contaminate batches of recycled plastic and harm recycling infrastructure. If bioplastic contaminates recycled PET, for example, the entire lot could be rejected and end up in a landfill. So separate recycling streams are necessary to be able to properly discard bioplastics.
The land required for bioplastics competes with food production because the crops that produce bioplastics can also be used to feed people. In addition, the petroleum used to run the farm machinery produces greenhouse gas emissions.
Right now, it’s hard to claim that bioplastics are more environmentally friendly than traditional plastics when all aspects of their life cycle are considered: land use, pesticides and herbicides, energy consumption, water use, greenhouse gas and methane emissions, biodegradability, recyclability and more.
While bioplastics have advantages, the education for what it is and how to dispose of it needs to be improved and our recycling infrastructure must progress in order to reap the environmental beneﬁts.