A new generation of plastics

Single-use compostables are becoming popular alternatives instead of conventional plastics. (bioplastics-future.eu)

From polluting precious ecosystems to killing sea turtles, single-use plastics might just be one of the most collectively hated things in 2019. A recent study revealed that oceans now contain over 5 trillion plastic pieces weighing over 250,000 tons collectively. Bans on plastic bags and straws are becoming commonplace across the world, with more legislation being passed all the time. 

Unfortunately, single-use plastics still a major part of modern society and they provide a convenience that we’ve all come to expect. The ability to grab a bottle of water, cutlery for your take-out meal, or even a bag to store your lettuce in at the grocery store are all conveniences allowed for by the mass production of single-use plastics.

There is a hopeful alternative, though. The growing popularity of compostable plastics, along with “bioplastics”, “green plastics” and other varietals, may provide a solution for our plastic-reliant society without requiring much behavior change on the side of consumers. Compostable plastics are comprised of renewable materials such as corn, potato, tapioca starches, and polyacidic acids (PLA)  rather than petrochemicals and fossil fuels (WorldCentric). These alternative, non-toxic plastics break down with the help of bacteria and decompose into biomass over time (in the right settings). Conventional plastics, on the other hand, can take up to 1000 years to decompose in landfills.

However, are these new compostable plastics really the ideal alternative to conventional plastics? Many would say, no, they are not. Bio-based plastics may be the lesser of two evils when compared to petroleum-based plastics, yet the widespread adoption of bioplastics may have no effect on littering and could actually reduce social responsibility when it comes to the disposal of single-use items.

One of the major issues when it comes to compostable plastic alternatives is consumer confusion–– often perpetuated by marketing language. “Biodegradable” and “biobased” are loose terms without concrete definition. These terms are often confused with “compostable” when they, in reality, are not the same at all. The term “biodegradable” can be used on a product without any information on the time it takes for the material to decompose. These items can still leave behind toxic residue once broken down, as many are still comprised of petroleum to some extent. Oftentimes, these products marked as “biodegradable” don’t actually break down as one would expect. In fact, a 2017 study comparing the biodegradability of bioplastic spoons to petroleum based plastic spoons revealed that the bioplastics actually gained weight instead of biodegraded.  

This graphic explains the breakdown of differently materials.

Although some companies are creating genuine plant-based plastics that are compostable in commercial composting settings, many are using the prefix “bio” as a green-washed marketing tool.

The confusion continues as many customers are unaware when they are using a compostable plastic and may toss it in the recycling bin or landfill after use. After all, compostable cups and utensils look very much the same to their conventional plastic counterparts. Lack of proper education regarding waste disposal is a major limitation of these plant-based plastics. It is a common misconception that these bioplastics or compostables will break down in landfills, or are able to be recycled like other plastics. In reality, tossing these “green” plastic products into the landfill defeats the purpose of them all together. PLA labeled materials must be composted in a high-heat, industrial composting setting where they may take up to 180 days to completely break down.

While composting programs are expanding throughout the country, the majority of US communities do not have access to curbside compost pickup or the ability to drop off their compostables. Over 180 communities in 18 states now have some form of residential composting programs, yet that is only a drop in the bucket. Until the infrastructure exists to support widespread composting, the use of PLA compostable plastics does not make sense for the greater majority. Plus, some experts believe that large amounts of PLA may actually interfere with conventional compost by making it wetter and more acidic. Although this is not an issue currently as PLA makes up very little of what goes into compost, it could create a greater problem as the use of these plastics, and composting in general, expands.

The composting process. (vegware.com)

One area in which PLA plastics clearly win compared to conventional plastics is energy usage and greenhouse gas emissions. Producing corn derived, PLA plastics use 65% less energy than conventional plastics and generate 68% less greenhouse gases (Smithsonian). These plant-based plastics are clearly easier on the environment than those comprised of fossil fuels. Nonetheless, there are also considerations to be made regarding the mass farming of crops like corn to produce non-food items such as these plastics and ethanol. Corn cultivation requires more nitrogen fertilizer, herbicides and insecticides than any other crop– all of which pose environmental threats. By converting all of our day-to-day plastic items into corn based plastics, there would need to be a major increase in the number of corn monocropping operations that already exist in excess today.

In summary:

  • Not all “green” bio plastics are created equally, and many are not actually compostable.
  • While corn-based plastics prove to be more environmentally friendly in comparison to petroleum based plastics, they are an imperfect alternative.
  • Lack of education and awareness leads to the improper disposal of compostable plastics, meaning they often end up in landfills where they do not break down or they contaminate recycling.
  • The infrastructure does not exist for industrial composting to expand the use of these plastics to all communities.

While PLA compostable plastics are an innovative alternative, they should not be the end of the line. In order to make the greatest amount of environmental change, we need to increase consumer responsibility as well as radically alter our policies and infrastructure. The implications of our single-use, throw away culture must be addressed. 

It seems as though the push to use less plastic is already beginning, slowly but surely. Some stores are beginning to incentivize consumers to bring their own cloth grocery bags and coffee cups through small, 10 cent discounts. While this is a great start, imagine the amount of single-use plastic that would be avoided if companies reduced or eliminates unnecessary plastic packaging. Or, if it became more normalized to bring utensils and reusable containers to restaurants instead of getting takeaway in plastic or styrofoam containers. It is a common misconception that businesses aren’t allowed to accept outside containers due to health and safety regulations, but there is no law actually preventing this. 

Examples of reusable items that function in place of single-use plastics.

Most change needs to come from both the top-down and the bottom-up. Even though compostable plastics are significantly better than conventional plastics when they actually end up composted, we can do better. Encouraging a bring-your-own culture on the individual level can keep great amounts of waste out of landfills, and companies will adjust according to cultural demands.


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4 responses to “A new generation of plastics

  1. seamusharrington

    I really enjoyed your article! I thought it was very engaging and had me intrigued the whole time. I thought your conclusion was very strong in that changes need to occur from bottom-up as well as top-down. I also thought that your images used helped portray your argument very well, especially with the small descriptions underneath each image. I do not have any issues with your article and think you did a very good job! Thanks for sharing


  2. Peter Newton

    Great post! Have any jurisdictions (countries, states) introduced laws to mandate compostable alternatives, and/or banned plastic?


    • erikaguth

      Hi there! Yes, there are many cases of this in fact. It might be useful to include some of these instances in my piece. Thanks for the thought.


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