Compostable vs Biodegradable

Last week I got a product I ordered online and it came in this bag;

Compostable Mailer

I was super excited to see the seller put some thinking into it and one that cares enough about the planet to choose environmentally friendly packaging. Compostable?! Amazing!

Since I’m a waste-nut I inspected the bag and it made me happy to learn this particular bag was not only compostable and made with plant-based materials, but also made from low impact resources. How cool is that?

Then I remembered in my region (Durham Region) not everything that’s labeled compostable can be thrown in the green bin. Only items certified by the Biodegradable Product Institute should be put in the green bin.

But first things first: what does compostable actually mean? And, is compostable the same thing as biodegradable? The answer is no. The differences between compostable and biodegradable are very specific and not interchangeable at all. So, let’s break it down (see what I did there?).

Composting is a natural process that turns organic materials (food, leaves, manure, certain type of paper and certified compostable items) into a material that improves the quality of soil. This process happens in very specific conditions where microorganisms require oxygen, moisture and food in order to reproduce. When all these factors are combined at specific levels, the natural breakdown of food happens faster.

You might or might not know that the list of  items accepted in the green bin in other regions, such as Toronto, is larger than in Durham Region. For example, in Toronto you can throw pet poop and diapers in the green bin. That’s because the city of Toronto processes their compost in a facility with different technology than that in Durham Region. Anaerobic composting (not available in Durham yet) creates an environment that’s so acidic that it can kill dangerous microorganisms. The technology used in Durham (aerobic composting) doesn’t have that quality.

Now, what the hell does Biodegradable mean? Biodegradable is a much broader term. Biodegradable means that a item will eventually break down through a non-controlled biological process. For example, if we leave a piece of fruit decompose in our kitchen counter, it will eventually decompose with the help or natural bacteria and fungi, because it’s an organic product. However, if an apple is composted, the composting conditions mentioned above will accelerate the decomposing process turning it into useful soil material. It’s important to know that everything that’s compostable is biodegradable, but NOT everything that’s biodegradable is compostable.  Some biodegradable products, such as biodegradable cutlery or plates, will not break down during the composting process. Therefore, if the biodegradable cutlery or plates get mixed with your compost, the biodegradable items will contaminate the compost. It is for this reason that municipalities have very specific lists of what can and what can’t be put in the green bins. In Durham Region items that are not certified compostable by the Biodegradable Product Institute or the Bureau de normalisation du Quebec should not be put in the green bin.



So where do items marked biodegradable but not compostable belong? The answer is in the garbage. Unfortunately, greenwashing has led to a common misconception that biodegradables are compostable or are better for the environment, when the reality is, that those products will end up in landfills, or in Durham Region’s case, incinerated (for more information on the Durham – York incinerator and incineration process check out Don’t get me wrong. Biodegradable products are better than plastic products because they will decompose faster, but they will still take months or years to break down releasing greenhouse gases into the atmosphere.

The compostable mailer I received my product in is made by a company called Noissue. Their products have a few certifications, and according to their website, they are BPI certified. However, they are not included in BPI’s certified product list. This very specific bag, which is currently sitting on my dining table, doesn’t have the BPI logo on it. It does have other certification logos such as European and Australian certifications, but not BPI’s. I have emailed the Region about it and they are currently investigating if their processing contractor can confirm the bag as acceptable or not.


As you can see, “compostable” and “biodegradable” labeled products are not as straight forward as it seems. I absolutely, whole-heartedly appreciate companies that care enough for the planet that they go out of their way to offer eco-friendly products whenever they can. It does require a bit more information from the consumer side to make decisions on these products too. Throughout my experience as a zerowaster, I have confirmed over and over, that the most environmentally friendly product is the one you don’t buy. Refusing and reusing are key in avoiding waste.


Tiny Earth Warrior



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