What Is The Difference Between Compostable and Biodegradable?

A great part of sustainable living is analyzing the impact of consumption, and what it means to buy something; not only where a product comes from, but also where it goes afterwards. ‘Biodegradable’ and ‘compostable’ labels, are sometimes used interchangeably, even though they aren’t the same. What’s the difference between a compostable and a biodegradable product?