The many, many types of “eco-friendly” plastic, explained

Seemingly overnight, new types of plastic are popping up in stores everywhere, labeled with adjectives and prefixes that signal their environmental-friendly properties: bio-based, biodegradable, compostable…to name just a few. It makes me happy to see mainstream companies putting more thought into their packaging, but I can’t count the number of times I’ve had to research or reach out to the manufacturer to figure out exactly what their packaging is and how to properly dispose them – and that is simply not realistic for the average consumer. Besides, are these materials really better for the environment? I set out to investigate.

First of all, let’s get one v important thing out of the way:

Environmental claims – i.e., labeling a product “compostable”, “degradable”, “recyclable” etc – is “somewhat” regulated in the US. At the federal level, there is the Federal Trade Commission (FTC), which first issued the Green Guides in 1992. The Green Guides include criteria for marketers to follow if they want to make specific environmental claims, and has been updated over the years. For example, to label something “recyclable”, manufacturers have to ensure that the product is recyclable in at least 60% of the communities where the product is sold.

However, the Green Guides are set forth by the FTC primarily to help marketers avoid making marketing claims that are unfair or deceptive, and generally don’t have a lot of “teeth” when it comes to enforcement. Additionally, any marketing claims can be manipulated without violating the guidelines but still cause enough confusion among consumers. For example, “organic” and “made with organic ingredients” have different definitions under the USDA’s organic labeling regulations, but consumers may not know or pay attention to the minute distinctions. 

In addition to the FTC, states and cities may have their own regulations. For instance, in 2017, Walmart paid $1 million to settle a lawsuit in California for mislabeling their plastic products “biodegradable” and “compostable”.

Point is: particularly with newer products or labeling that you’ve never heard of before, take their environmental claims with a grain – scratch that, a big bucket – of salt. Now we have that out of the way…

Conventional plastic is made from petroleum, a non-renewable resource. The number 1-7 is used to classify their varying chemical structures and applications. Some plastic produces hazardous material after several uses; others might be reusable and heat-resistant. Some are easily recyclable; others are not due to lack of technology, infrastructure, or cost-effectiveness.

Image credit: Our World in Data.

While conventional plastic is incredibly versatile and cheap to manufacturer, we are now drowning in its environmental problems. Since mass production began in the 1950s, we have created more than 9 billion tons of plastic, only 9% of which has been recycled; 12% is incinerated, and the rest ends up in landfills, open dumps, or our oceans and riverways, destroying marine life. Conventional plastic can take more than 500 years to degrade.

Enter bioplastic, biodegradable, and compostable plastic. These terms aren’t precise in their meaning, nor are they mutually exclusive – but these are labeling you might see most often. Let me explain one at a time:

In the most simple terms, bioplastic (sometimes called bio-based plastic) is made from plants: corn, sugar cane, cassava, sugar beets, etc. Compared to conventional plastic, bioplastic may produce less greenhouse emission over its lifetime because when bioplastic breaks down, it’s simply returning the carbon the plants absorbed while growing, instead of releasing carbon previously trapped underground in the form of fossil fuels.

Image credit: Tom Fisk via Pexels

However, just because bioplastic is made from plants doesn’t mean it will break down in a meaningful time frame in nature. But that’s as far as the consensus goes. I’ve spent hours researching the proper disposal of bioplastic, and encountered a slew of conflicting information. And I’m not the only one; bioplastics are causing huge problems for recyclers and composting facilities because they are often incorrectly sorted.

My own takeaway is that if it can break down at all, most bioplastic needs high temperature industrial composting facilities to decay properly, and only some bioplastic can be recycled because our current recycling system is mostly built to process conventional fossil-based plastic.

So what’s one to do?

  1. If it is labeled #1, PET, or PETE, you can put it in your recycling bin. These are bioplastic that maintain the same property as conventional #1 plastic.
  2. If it is labeled #7 (which means “other” in the plastic classification code) and if your city accepts #7 plastic (which is rare), you can also place it in the recycling bin.
  3. Do not put bioplastic in your backyard compost pile. Whether any particular industrial composting site can handle bioplastic largely depends on the material it is made from. As a rule of thumb, my composter Bootstrap recommends looking for the BPI (Biodegradable Products Institute) logo, or a combination of #7 + PLA symbol to determine “compostability.” PLA stands for polylactic acid; you can geek out all about it here.
  4. If the bioplastic is unlabeled and unnumbered and you do not have access to an industrial composting facility, most likely you have to put it in trash. But you can always reach out to your municipality to confirm.

In contrast, biodegradable plastic, as you might see labeled on some packaging, can be made from both petroleum or plants. In other words, some bioplastic might be labeled with the adjective “biodegradable” to signal their biodegradability, and should be treated as I discussed above. In other cases, biodegradable plastic is made from the exact same material as conventional plastic, but with added chemicals to help it break down faster. Sometimes, you might even see more specific labels like “oxodegradable” or “photodegradable”, which means these plastics contain additives that will cause them to decay faster in the presence of oxygen and light.

Coffee bag from George Howell. Part of the bag is made from wood pulp (compostable), and part of the bag is made from biodegradable petroleum-based plastic with an additive that’ll help it break down in 5-10 years.

Petroleum-based biodegradable plastic can’t be effectively composted. Therefore, unless they are recycled, they end up littered or incinerated just the same as conventional plastic. When littered, petroleum-based biodegradable plastic breaks down into tiny plastic fragments (“microplastic”), as conventional plastic does, which still harms marine life and introduces other environmental problems, such as leaving behind toxic residue from the chemical additives.

Lastly, we have compostable plastic, which is supposed to mean that the material will disintegrate into carbon dioxide, water and biomass, and not leave any toxic material behind. (And by “supposed”, I refer you back to the Walmart lawsuit linked above.) Some compostable plastic will break down in your backyard compost pile; others need to be handled by an industrial composting facility, which grind and turn the materials consistently to reach a higher temperature. Should you put compostable plastic in your compost pile? I leave that to your own wise judgement. For example, a thin compostable produce bag will break down a lot faster than a Sweetgreen bowl.

Phew, thanks for making it all the way here! To recap:

  1. “Bio-based”, “biodegradable” and “compostable” are not the same thing. A product may have all 3 attributes, or just 1. The afterlife of these materials depends on what it is made of. 
  2. Aside from accurate labeling, these plastics are almost indistinguishable from conventional plastic to the average consumer. So always read the label, ask questions, and do your research to find out whether to compost, recycle or dispose.
  3. If any of these materials ends up in landfill, they will not break down in a short period of time because materials need heat/light and oxygen to decay.
  4. The environmental impacts of these alternative plastics vary. For example, some has estimated that environmental impacts from cultivating crops to manufacturer bioplastic (including land use, fertilizers, pesticides and herbicides etc) are potentially larger than that of conventional plastic.
Case in point: these bags I use to line my compost bin are bio-based, biodegradable and compostable.

Bottom line: some of these new “eco-friendly” plastics might be better alternatives to conventional petroleum-based plastic, but their environmental impacts depend on the source material, production method, and proper disposal – the last of which is incredibly challenging for consumers, simply based on my own experience researching for this post alone. Ultimately, these alternative plastics largely aim at the “waste disposal” aspect of our plastic problem, and not the widespread misuse and single-use nature of it. So until the real miracle material comes along, don’t count on the bioplastic, biodegradable or compostable plastic currently on the market to get us out of plastic problem. 

(I read many, many articles for the research of this post, but I found these 3 to be most informative. Read this excellent explainer here, a deep dive on bioplastic here, and this detailed piece explaining the specific chemical structures of these alternative plastics here.)