What is the difference between the two?
What is the difference between biodegradable and compostable?
People use terms like biodegradable and compostable a lot and interchangeably, but there’s a world of difference between the two. Knowing the terms, and what they mean, can help you make smart, eco-friendly choices.
While some use the terms Compostable and Biodegradable interchangeably, they are not! Compostable products break down into non-toxic components during the composting process. In contrast, other products claiming to be biodegradable can break down into harmful chemicals and smaller fragments, like microplastics, that can harm the environment or do not work as advertised. Some confuse composting with biodegrading by thinking that both mean defragmentation, where the material degrades into smaller pieces but does not decay in any molecular way.
When you hear the term “greenwashing,” it came about because marketers used buzzwords like biodegradable or degradable to mislead customers about how beneficial their products were for the environment. Appropriating the terms in this way leads to much confusion regarding the meaning of such key terms as compostable, biodegradable, degradable, and oxo-degradable.
ASTM defines compostable as anything that undergoes degradation by biological processes during composting to yield carbon dioxide, water, inorganic compounds, and biomass at a rate consistent with other compostable materials. It must leave no visible, distinguishable, or toxic residue.
To compost organic waste requires the proper levels of heat, water, and oxygen. After their degradation, compostable products will leave behind humus, which is non-toxic, full of nutrients, and nourishes plants and soil.
Compostable products positively impact the environment. Combined with organic waste, compostable products help divert organic waste from landfills, and the end product of the composting process is nutrient-rich soil.
Most compostable products are certified for composting in a commercial composting facility. Making sure compostable packaging ends up in a commercial facility ensures proper waste management, the quickest disintegration process, and the best end product.
Biodegradable products are anything that undergoes degradation resulting from the action of naturally occurring microorganisms, such as bacteria, fungi, and algae. In other words, for something to be considered biodegradable, living things need to be able to break it down. The prefix “bio” makes this term seem very eco-friendly. However, just because nature breaks these products down does not mean the results are any better for the environment. It is important to specify the setting and conditions where biodegradation should occur.
The term degradable defines a broad category of products that, when exposed to sunlight, heat, moisture, etc., will break down and disintegrate over time. That said, almost anything will degrade, given enough time. Concrete will eventually degrade, as will steel.
Even if something is degradable, it might not benefit the environment. For example, non-compostable plastics left to degrade in the terrane or marine environments create harmful micro-plastics.
Oxo-degradable plastics contain polyethylene and additives (including iron, nickel, and cobalt). Once disposed of, these plastics undergo oxidative degradation, a process requiring oxygen, ultraviolet light, and heat. The degraded plastic becomes brittle and fragments easily, creating micro-plastics that are incredibly harmful to the environment.
Oxo-degradable products are considered generally harmful to the environment in most environmentally conscious quarters. They are not compostable or suitable for recycling with mainstream plastics, so they must be thrown away into general waste receptacles.