Many believe that products dubbed “biodegradable” are automatically good for the environment. But the reality is that the term “biodegradable” only means that the product will break down in nature at some point. It does not mean that the product will decompose rapidly.

Most biodegradable products have their decomposition abilities tested under ideal conditions — just the right amount of sun, water, oxygen, and soil conditions. Nature rarely provides ideal conditions. One study found that a “biodegradable” grocery bag could still carry several heavy books more than three years after being buried in the ground or drifting at sea. 

This post is part of a weekly series on environmental myths. You can find more myths here.