The problem with bioplastics

compostable food tray
CC BY 2.0 Doug Beckers

They're not as green as they seem.

Plastic was once hailed as a miracle material, but as its favored sheen slowly wears off with better understanding of its environmental repercussions, bioplastics are now rising to the forefront as the savior of the future. Bioplastics, the thinking goes, will enable our consumption habits to remain more or less the same because we won't have to worry about where the plastic ends up after use. It breaks down, so that's good, right?

Unfortunately, it's not that simple. A revealing chapter in "Life Without Plastic: The Practical Step-by-Step Guide to Avoiding Plastic to Keep Your Family and the Planet Healthy," a brand-new book written by Jay Sinha and Chantal Plamondon, founders of the eponymous website, takes a closer look at bioplastics, the confusing terminology, and what it all means.

The industry is booming, predicted to grow 50 percent by 2020 and possibly replace 90 percent of traditional fossil fuel-based plastics someday. While Sinha and Plamondon think that bioplastics can be part of the solution, they do not think they're the silver bullet everyone is making them out to be. Here are some of the descriptions you'll see on bioplastic products:

Bio-based: This refers to the product's beginnings, that it's been made with a renewable material of sort, such as corn, wheat, potato, coconut, wood, shrimp shells, etc. But only a small portion of the plastic may be renewable. To be called a bioplastic, a material only needs 20 percent of renewable material; the other 80 percent could be fossil fuel-based plastic resins and synthetic additives.

Biodegradable: This refers to the product's end-of-life and means that it will "break down completely in the natural environment through the action of naturally occurring microorganisms such as bacteria, fungi, and algae," although it makes no promises about not leaving a toxic residue behind.

The assumption is that it will happen in within a single season, but a lot depends on where the item ends up. If it's the ocean, biodegradation may not even occur, according to a recent report by the United Nations Environment Programme (UNEP), which stated in its Executive Summary that “plastics marked as ‘biodegradable’ do not degrade rapidly in the ocean.”

A sub-category is oxo-biodegradable plastics, a phrase often seen on grocery bags and a classic example of greenwashing:

"These are traditional fossil fuel-based plastics... that have been combined with what are called transition metals -- for example, cobalt, manganese, and iron -- which cause fragmentation of plastic when triggered by UV radiation or heat. The additives make the plastic break down faster."

Degradable: The plastic is capable of breaking down into smaller pieces that will disseminate into the surrounding environment. This is meaningless, as all plastics will break down eventually, and this is not a good thing; bigger pieces are less easily mistaken as food by wildlife.

Compostable: The material will break down "at a rate consistent with other known, compostable materials and leaves no visually distinguishable or toxic residue." But for the vast majority of bioplastics, this requires an industrial composting facility, not a backyard composter -- and I have yet to figure out where an industrial composter exists in my community or how to get bioplastics to it.

Advocates say the carbon footprint of bioplastics is better than fossil fuel-derived alternatives, which is true, but as "Life Without Plastic" points out, there's the added issue of supporting genetically modified corn production, which currently provides most material for bioplastics.

Shoppers cannot blindly trust labels like "natural," "bio-based," "plant-based," "biodegradable," or "compostable," since manufacturers can put pretty much anything they please on a product. However, the more conscientious ones will get a third-party certifier, resulting in labels such as the Biodegradable Products Institute (BPI in North America), "Compostable" certification in Canada, and the European Bioplastics "Seedling" logo, just to name a few. (See "Life Without Plastic" for more in-depth information about these certifications.)

"To be called a bioplastic, a material only needs 20 percent of renewable material; the other 80 percent could be fossil fuel-based plastic resins and synthetic additives."

Even if you end up with compostable bioplastic, you might not be able to find an industrial composting facility and you cannot throw it in with your organic waste for curb-side pickup, as most organic composting facilities in the US and Canada do not accept bioplastics. TreeHugger writer Lloyd tells me they are banned from the Toronto composting system. So, really, it's as if this label means nothing if the facility required to break it down is inaccessible to the majority of the population. (I'm still digging on this topic, and will get back to you on how to get bioplastics to an industrial composter most efficiently.)

Most people would toss these in recycling, which causes additional problems by contaminating the regular recycling stream. A commenter wrote on TreeHugger's article on the UNEP report:

"A family member works in the recycling industry. He says the biodegradable plastics a big problem when people put them in the recycle bin. The biodegradable plastic can ruin a batch of recycled plastic, rendering it useless, and it all has to go to landfill."

It's one big hot mess, as you can see, and there are no clear-cut solutions except to reject single-use plastics and embrace reusables. If you absolutely must choose a disposable item, opt for easily-recyclable materials like glass or metal. If it has to be plastic, ensure it's been made with biodegradable additives and is compostable in a home composter.

Do not blindly accept the notion that a single-use plastic cup inscribed "made with corn" is somehow going to save our planet. It won't. It's simply a distraction from the lifestyle changes that truly need to occur.

Lots more to come from "Life Without Plastic," a book I think everyone should read. Coming December 12th, but available for pre-order on Amazon.

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