What does biodegradable mean? How is it different from compostability?

The terms “biodegradable” and “compostable” are everywhere, but they’re often used interchangeably, incorrectly, or misleadingly – adding a layer of uncertainty for anyone trying to shop sustainably.

In order to make truly planet-friendly choices, it’s important to understand what biodegradable and compostable mean, what they don’t mean, and how they differ:

Same process, different breakdown speeds.

Biodegradable

Biodegradable products are capable of being decomposed by bacteria, fungi or algae and will eventually disappear into the environment and leave no harmful chemicals behind.  The amount of time is not really defined, but it’s not thousands of years (which is the lifespan of various plastics).
The term biodegradable refers to any material that can be broken down by microorganisms (like bacteria and fungi) and assimilated into the natural environment. Biodegradation is a naturally occurring process; when an object degrades, its original composition degrades into simple components like biomass, carbon dioxide, water. This process can occur with or without oxygen, but it takes less time when oxygen is present— like when a leaf pile in your yard breaks down over the course of a season

Compostable

Products that are capable of decaying into nutrient-rich, natural material under controlled conditions in a commercial composting facility.  This is achieved through controlled exposure to microorganisms, humidity and temperature. It will not create harmful micro-plastics when they get broken down and have a very specific and certified time-limit: they break down in under 12 weeks in composting conditions, and is therefore suitable for industrial composting.

The term compostable refers to a product or material that can biodegrade under specific, human-driven circumstances. Unlike biodegradation, which is an entirely natural process, composting requires human intervention
During composting, microorganisms break down organic matter with the help of humans, who contribute the water, oxygen, and organic matter necessary to optimize conditions. The composting process generally takes between a few months and one to three years.The timing is impacted by variables like oxygen, water, light, and the type of composting environment.