A paper bag is not only biodegradable, it’s also compostable; a biodegradable plastic bag isn’t necessarily compostable.
Some definitions should not be confused…
It is important to understand the meaning of “compostable” and “biodegradable” because they are not equivalent and should not be used interchangeably. The following definitions are adapted from those used by the American Society for Testing and Materials (ASTM):
- Degradable: That undergoes significant changes in its chemical structure when subjected to various specific environmental conditions, resulting in a loss of properties that can be measured by standard methods, in a given period of time.
- Biodegradable: That undergoes degradation resulting from the action of naturally occurring microorganisms such as bacteria, fungi and algae. There is no reference to the amount of time needed for degradation or the type of physical and chemical quality attributes of the end product.
- Compostable : That undergoes degradation by biological processes during composting to yield CO2, water, inorganic compounds and biomass at a rate consistent with other compostable materialsand leaves no visible, distinguishable or toxic residue.
- OXO-biodegradable: Material to which a metal-based additive is added to accelerate degradation by sunlight (UV), heat and / or mechanical stress. This first degradation results in small fragments, often invisible to naked eye, that could be biodegraded in a second degradation phase.