“Biodegradable” a word with multiple meanings

For most of us, it has been a long time since we last took a class on Earth sciences. If you haven’t picked up a science textbook in 20 years, it might be time for a refresher. Or, if you think that you’re a nature know-it-all, now is your time to prove it. Here’s a pop quiz:

What is the definition of Biodegradation?

I’m positive you’ve seen or heard this word before, tagged onto an eco-friendly product, or used in a news article, but do you know its exact definition? Would you be surprised to learn that scientists generally disagree on classifying materials as biodegradable and that the definition changes depending on where you live?

Biodegradation as a law of nature.

Assumedly, most of you had an excellent answer to the pop quiz: “The natural process of a product decomposing.” While this is somewhat correct, it’s not the whole picture.

While there is no universal definition, in general, biodegradability is the capability of organic material to be broken down or decayed by means of microorganisms. Scientists go on to classify this definition even further. There are actually two different types of biodegradations: aerobic and anaerobic.

When oxygen is present during the biodegradation process, it is referred to as aerobic. When oxygen is not present, it is called anaerobic. The general concept is the same, microorganisms eat the organic material and break it down into other materials. The presence of oxygen changes the time this process takes, how much of the material is broken down, and the byproducts that are left over.

All organic material is biodegradable. The apple core you had left over from breakfast? Of course. Your nicest cotton shirt that has a hole in it? Still yes. The aluminum can that you got with your lunch? Actually, it is. However, its decomposing process could take hundreds if not thousands of years. So, what distinguishes your favorite green product with a “biodegradable” label on it from a plastic bag or glass bottle?

Biodegradation as a rule of law.

As simple as it would be to let scientists create a universal designation for products that are or are not biodegradable, this is where world governments cut in. Depending on which country you live in, a product must meet specific criteria for a product to earn the lucrative title of biodegradable. Remember the earlier assumption that your answer to the pop quiz was good? Well, in the eyes of the government, it is not quite good enough. Look at the U.S. government’s definition of a biodegradable product.

“All ingredients in the candidate product must achieve the pass level in a Ready Biodegradability Test; According to Organization for Economic Cooperation and Development (OECD) and Office of Chemical Safety and Pollution Prevention (OCSPP) guidelines, the pass level must be reached in a 10-day window….”

That’s pretty strict; not much room for error. Unless you helped write these regulations, this was likely not your answer to the pop quiz. Now let’s take a look at the definition that the E.U. provides.

“Biodegradability: the conversion of >90% of the original material into CO2, water, and minerals by biological processes within six months.”

Not nearly as much of a mouthful. This is due to the E.U.’s lack of an official and universal test for biodegradability across different industries.

So, if there isn’t a strict guideline for products to meet, who determines whether a product is or isn’t biodegradable? As stated earlier, all organic matter is biodegradable; it just takes different amounts of time. What stops a plastic bag company from writing “biodegradable plastic” on the side? They’re not wrong; they just haven’t told us how long it will take. Ten years? 100 years? 1000 years? Who’s to say if there are no guidelines.

Author