How sustainable are biodegradable and plant-based plastics?

Tom Szaky in Sustainable Packaging on May 30, 2017

Finding solutions for the world’s plastic problem is an uphill battle. Manufacturers and consumers alike are now accustomed to products and packaging made lighter, less costly and more convenient by plastic, the iterations of which have only grown more complex. As it stands, we are manufacturing approximately 300 million tons of plastics across the world every year, and this number continues to grow.

The scope of the world’s plastic problem goes beyond straining Earth’s finite resources; it is also a waste management issue. It is estimated that up to 129 million tons (43%) of the plastic used per year is disposed of by landfill or incineration, and approximately 10 to 20 million tons of plastic ends up in the oceans.

Rethinking all aspects of the plastics supply chain in terms of full lifecycle, from sourcing to end-of-life, is the key for manufacturers and major brands aiming to design into a more circular plastics economy. Driven by demand for more sustainability and positive environmental impacts in consumer packaged goods (CPGs), there is a growing industry for bioplastics—plastics made from plant biomass, such as corn.

One argument in support of increased use of bioplastics is mainly that the raw materials used to generate it are more sustainably sourced than petroleum-based plastic. Abundant availability of raw materials for manufacturing bioplastics place less strain on resource supply, as well as cause less strain to the earth from sourcing processes. Drilling for oil to use for petroleum-based plastic may disturb land and ocean habitats, and is a major source of emissions and airborne byproducts.

Bioplastics can be broadly broken down into two categories: durable and biodegradable. For instance, the PlantBottle is a durable bioplastic alternative to traditional PET bottles made by Coca-Cola. Made with up to 30% ethanol sourced from plant material, the PlantBottle won’t decompose, but it can be recycled with traditional PET containers and bottles. It is important to note that this is an outstanding example, as not all bioplastics are recyclable.

Of the many bioplastic varieties currently on the market or in development, no variant has attracted more attention than those dubbed “biodegradable.” Biodegradable bioplastics, like increasingly popular PLA (polylactic acid), are exactly as they sound: in theory, they break down naturally in the environment or may be composted. This is unique, as the vast majority of plastics today will never break down. Petroleum plastics may degrade into smaller and smaller pieces, but most won’t decompose or be absorbed by the surrounding environment.

Where bioplastics theoretically are an answer to our dependence on fossil fuels to manufacture the plastics the world demands, biodegradable bioplastics are meant to be a solution for the world’s plastic waste problem. However, in most cases, biodegradable bioplastics will only break down in a high-temperature industrial composting facility, not your average household compost bin. Plus, these are not recyclable.

This wouldn’t be as much of a concern if we had a great composting infrastructure, but we don’t. With only about 200 industrial composting facilities in the United States and 50 million tons of organic waste still ending up in landfills across the country each year, we are ill-equipped to adequately compost any meaningful volumes of biodegradable plastic. In fact, many operational industrial composting facilities today won’t even accept PLA and other biodegradable plastics—they are seen as contamination risks.

A better solution might be to place the focus on durable bioplastics that are made from plant materials, but can still be recycled. This way, the valuable energy and material inputs can be kept in the production cycle longer. It also makes far more sense to build a bio-based plastic that fits into our existing infrastructure, rather than building an entirely new biodegradable plastic composting infrastructure from scratch.

If we hope to truly make durable bioplastics as viable as they could be, we will need to start curbing the demand for plastics overall. With less demand, the market will be in a far better place to meet demand with more contained impacts to the environment. How do we reduce the demand for plastic? When manufacturers and major brands commit to packaging designs that are more durable and made to last, consumers have the opportunity to make more sustainable purchasing decisions.


Author Tom Szaky, founder and CEO of TerraCycle, has won more than 50 awards for entrepreneurship, writes blogs for Treehugger and Triple Pundit, published a book called "Make Garbage Great" and is the star of the television show "Human Resources.”



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Sorry. But this does not make sense at all. Both compostable and plant plastic comes from the same source...plants. So instead using water and land to grow crops to feed people we are using to feed and make plastic. Also the plant plastic will also ends at the same locations as a regular plastic that comes from oil - recycling or landfills or as litter just as you described in your article. Exactly the same. So for both reasons does not make sense at all the use plastic that comes from plant.
The point is that when hemp or bamboo and the like are grown for mass production of plastics, paper, fiber cloth, can be grown to harvest in 4 months and the carbon exchange from planting and harvesting these plants will over time begin to slow and then reverse the green house gasses.. This is of course if nations are committed to phasing out dirty energy like fossil fuels, polypropylene, make steps to solar and so on Does that answer your q?
The Eco Connect Bottle System was designed with a simple repurpose functional, durable PET materials and give them a productive new life. It is potentially the first non-returnable water bottle that can reduce the transportation, energy costs and pollution associated with recycling.
ate:October 25, 2010 Source:University of Pittsburgh Summary:Researchers analyzed plant and petroleum-derived plastics and found that biopolymers may not necessarily be better for the environment than petroleum-based plastics. While biopolymers are the more eco-friendly material, traditional plastics can be less environmentally taxing to produce.
The production of plastics need to be redesigned in the same way we are changing from fossil based energy to renewables. Compostable plastics most certainty have their place especially in applications such as food service disposables where the packaging will be contaminated with food residues making it difficult to recycle. The compost infrastructure needs to be further developed to manage the significant volume of organics currently ending up in landfill
PLA was studied "cradle to grave" by 2 US scientists and their results showed a 151% increase in energy used to make Plastics from Corn as opposed to Oil. ( American Scientific, Aug. 2000 ). Growing the corn with tractors and farm equipment, transporting the corn to a processing plant perhaps 1000 miles away, Processing it into plastics. Not to mention the Nitrogen used that washes down to the ocean creating 10,000 sq. km .Dead Zones where there is no oxygen to support marine or plant life.
Interesting to read the amount of misinformation both in Tom's article and the comments that follow. There is a misconception that the corn used to produce products like PLA are taking away from the food used for human cons.; the corn used for bioplastics is also the same corn used to produce the starches that go into all types of paper, high fructose corn syrup, etc. By the way, PLA would be just as recyclable as PET if the industry would allow PLA to have a stand-alone number like PET.