The difference between Degradable, Biodegradable, and Compostable | Green Plastics
There are three terms that get thrown around a lot when people talk about plastics, so it is worth spending a moment to clear up how they are related to one another, and how they are different.
Degradable Plastic. The word degradable just means that something breaks down. Technically, all plastic is degradable plastic. You can break it with a hammer. You can grind it into a fine powder. This all counts as breaking down the plastic, and therefore (technically) degrading the plastic.
This creates a little bit of confusion, because some plastics will add chemicals that will make the plastic break down faster under certain conditions. For example, you can add an additive to normal, petroleum-based plastic that will make it become brittle and crumble in sunlight: this is referred to as making photodegradable plastic. Other additives can be put into plastic that will make plastic break down by oxidation: this is referred to as making oxo-degradable plastic.
These methods will make the bulk of the plastic appear to disappear; however, the small pieces (or even find sand) that is produced by this effect is still small pieces of plastic. Nothing has changed. Over a matter of years, it is possible for the pieces to become small enough to be assimilated by microorganisms, but there is still a lot of research that needs to be done to verify how long this might take. In the mean time, they are just very small pieces of plastic.
So be cautious when you see a plastic product that advertises that it is degradable but not biodegradable or compostable, because this is nothing special. The plastic material does not return to the earth in any real way. It just gets really, really small. (You can read more about why this is different from biodegradation in our article:
Degrading Dialogue (Achilles and the Tortoise).)