What is the difference between “biodegradable” and “compostable” ?

Biodegradable refers to the breaking down of materials. Thus, strictly speaking anything is biodegradable if enough time is given. Examples are like plastic, as they can biodegrade. It just takes an extremely long. However, composting refers only to the breaking down of organic materials in conditions like suitable temperature and humidity levels, and refers only to the breaking down of organic materials in conditions like suitable temperature and humidity levels, and usually only require 3-6 months. The reason these 2 terms are always confused is because “biodegradable” is often used to refer to compostability of a material, which is passes off the material as something it is not. Thus, standards like the EN 13432 and ASTM D6400 are created to properly determine the compostability of a material. In summary, not everything biodegradable is compostable, but everything compostable is biodegradable.