Are Biodegradable Plastics Better for the Environment?

#EcoAdvice from our expert

Dear Dr. Donley,

I’ve read a lot lately about the harms of plastic glitter in the environment. With summer festival season just around the corner, I’ve thought about buying biodegradable glitter made from plants. I’m wondering if this is much better for the environment. If so, what’s the best way to dispose of it?

Signed,

Glitterally Asking if My Glitter Is Still Litter

While no one can doubt your commitment to Sparkle Motion, let’s first unpack what “plant-based,” “bio-based,” and “biodegradable” actually mean — because they sound a whole heck of a lot better than they often are.

Most plastics are made from extracting fossil fuels like coal, natural gas or petroleum from the ground and refining them into petrochemicals, which are then mixed with additives to produce plastics with a wide variety of shapes, colors, flexibilities, etc. This is a very energy-intensive process that’s highly polluting. It extracts a lot of carbon from the ground and brings it into our atmosphere.

Alternatively plant-based or bio-based plastics use organic matter that was generated very recently, not millions of years ago like fossil fuels. Making plastics from new carbon sources like plants has the benefit of a reduced carbon footprint because the plants used for the plastic capture carbon from the air — turning the process into a carbon cycle as opposed to simply extracting and releasing.

But just because a product comes from plants doesn’t mean it will break down quickly. For example, polyethylene (PE) can be made from both petrochemicals and ethanol derived from plant matter, and the strong carbon-carbon bond that makes PE so resistant to degrading is present either way. So some plant-based plastics will be around just as long as traditional petroleum-based plastics, choking out marine life and contaminating the food web.

Other plant-based plastics are made from polysaccharides like cellulose or starch. In a relatively unprocessed form, cellulose is used to make paper. So how do you get from paper to something that won’t break apart in water and is as clear as glass? A whole lot of chemical processing. This processing often involves toxic chemicals and a lot of energy. It turns something that would normally biodegrade quickly into something that will likely outlive you and even your children. Hardly an acceptable time frame.

Which brings us to the term “biodegradable.” Technically even petroleum-based plastics are biodegradable; it just takes thousands of years for them to break down. This term means nothing, because there’s no time scale associated with it. The term “biodegradable” is a huge red flag for greenwashing.

A term that does mean something is “certified compostable.” There are various international and U.S. standards that actually define “compostable;” the bad news is, they all define it in terms of industrial composting methods. In the real world, most of us don’t have the ability to make sure compostable plastics actually make it to a facility where they can effectively be broken down — pretty much defeating the point. If your compostable plastic ends up in a landfill or the ocean, it’ll be around for a very, very long time.

It’s easy to hope we can change things by just buying something different or supporting a different business instead of changing our underlying behavior. As we make progress in ending fossil fuel extraction for plastic production, it’s important that our definition of what we view as necessary in our lives begins to shift as well. Nothing can be used on the scale that we currently use plastic and not be extremely degrading to our natural environment in one way or another.

That said, if you’re on the go and forced to choose between eating your salad with a plastic fork or a comb, go for the plant-based plastic if you can. Bonus points if it’s certified compostable and you’re able to dispose of it at an industrial composting facility. Good luck not getting frustrated with that one.

There are also times in life when you just have to get your glitter on (or so I’ve heard). Since composting plant-based glitter is not an option due to the metals and dyes the plastic is mixed with, try collecting it and donating to your local KISS cover band? Are glitter bombs still a thing? What else do people use glitter for?

Stay wild,

Dr. Donley

For more info, check out our plastics campaign to see how the Center is working to affect change

Dr. Nathan Donley is a scientist at the Center for Biological Diversity who answers questions about how environmental toxins affect people, wildlife and the environment. Send him your questions at AskDrDonley@biologicaldiversity.org

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