Climate Conscious
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Climate Conscious

Biobased Plastic Doesn’t Always Mean Biodegradable

And it isn’t easily recycled.

A person wearing plastic medical gloves. They are holding 4 biodegradable, compostable ECO cups. The person is wearing a blue shirt and black pants. They are standing on the beach.
Photo by Brian Yurasits on Unsplash

We keep hearing and seeing the word biodegradable, but do any of us really know what it means?

I’ve always assumed it’s the base of the word. Something that degrades to a point where it becomes useful to the natural environment again.

I hadn’t considered the “bio” part of the word. I thought it pertained to the biological part of the world. The natural environment as opposed to the manmade environment.

In my mind, this goes hand in hand with composting. If something is able to break down, then that’s what composting is.

Except it’s not.

The European Environment Agency outlines the various types of plastic:

  • Biodegradable plastics are designed to biodegrade in a specific medium (water, soil, compost) under certain conditions and in varying periods of time.
  • Industrially compostable plastics are designed to biodegrade in the conditions of an industrial composting plant or an industrial anaerobic digestion plant with a subsequent composting step.
  • Home compostable plastics are designed to biodegrade in the conditions of a well-managed home composter at lower temperatures than in industrial composting plants. Most of them also biodegrade in industrial composting plants.
  • Biobased plastics are fully or partly made from biological raw materials as opposed to the fossil raw material (oil) used in conventional plastics.
  • Non-biodegradable plastics last for long periods of time. They can disintegrate into smaller pieces, forming microplastics, and accumulate in the environment.
  • Oxo-degradable plastics include additives that, through oxidation, lead to their fragmentation into microplastics or chemical decomposition.

The next part is a bit confusing. All compostable products are biodegradable, but not all biodegradable products are compostable.

Plastic needs to say “compostable” somewhere on it for it to be compostable in some form or fashion.

On top of that, don’t assume compostable plastics can go in your home compost pile. Most only break down in a commercial facility under the right oxygen and heat conditions.

According to the United States Environmental Protection Agency:

“Plastic that is labeled as compostable is generally intended to be sent to an industrial or commercial composting facility which has higher temperatures and different breakdown conditions than those found in a typical homeowner’s compost bin.”

All those compostable coffee pods and coffee cups aren’t meant for your home compost bin. Which you’re then likely thinking, you’ll just dump them in the trash and they’ll compost there.

“Most compostable plastics, made primarily of the polyester known as polylactic acid, or PLA, end up in landfills and last as long as forever plastics.” Robert Sanders, Berkeley News

I’ve been to quite a few events, where the venue has elected to use compostable cups. This is great, but they haven’t provided compost bins, so all those compostable cups go in the trash.

On the surface, it looks better because they used biobased plastic. In reality, those cups are going to last as long as forever plastics.

Those venues also likely had no idea this was the case. This information is not widely known or readily available.

Which, the word and meaning of bioplastic in itself are confusing and unclear. I would assume all bioplastics are biodegradable. This is not the case.

“Nearly half of the bioplastics produced are not biodegradable.” Dr. Molly Zhongnan Jia (Biodegradable Plastics: Breaking Down the Facts, P. 6)

I’m disappointed in myself for not researching this sooner. I’m disheartened by the companies that are deceiving us.

It’s not all bad though. On the other side, fossil-based plastics can also biodegrade if they’re designed to do so.

European Bioplastics notes:

“The property of biodegradation does not depend on the resource basis of a material but is rather linked to its chemical structure. In other words, 100 percent biobased plastics may be non-biodegradable, and 100 percent fossil based plastics can biodegrade.”

We don’t actually need plastic to be 100% plant-based to biodegrade.

Plus, it’s not the whole solution.

If we replaced all fossil-based plastics with plant-based, we’d need a lot of plants. Possibly resulting in more deforestation than there already is. Or reduced agriculture production for food needs on top of the famines already occurring.

Dr. Molly Zhongnan Jia in Biodegradable Plastics: Breaking Down the Facts, P. 15, Box 3.2 puts it in perspective:

“The amount of corn used equals to 32% of global annual corn production, or more than all corn produced in the US this year. To grow this amount of corn would use 1% of global agricultural land.”

We’d be swapping one issue for another.

Then there’s the whole deal about how long it takes for something to decompose. If it’s in compost, it needs to take 6 months or less. Which is in line with the time it takes the other matter to compost.

If it’s not compostable, the FTC has put some sort of limit on this terminology for the duration to degrade.

At first glance, it appears pretty vague, “reasonably short period of time.” Except the FTC goes on to clarify what that is, “The ‘reasonably short period of time’ for complete decomposition of solid waste products? One year.”

At least there’s a start on somewhat of a timeline.

Ultimately, we need to use less plastic. Yes, there are plenty of necessary applications for plastic. But we don’t need every water bottle or grocery bag to be plastic.



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