Compostable materials have a role to play in the circular economyA systems solution framework that tackles global challenges like climate change, biodiversity loss, waste, and pollution. It is based on three principles, driven by design: eliminate waste and pollution, circulate products and materials (at their highest value), and regenerate nature., but they are not a silver bullet.
The term compostable is often confused with the terms biodegradable and bio-based. This can lead to some solutions being mishandled and their environmental impacts miscommunicated. These terms can be distinguished as follows:
Biodegradable: able to be broken down into carbon dioxide, water, and biomass by the natural action of microorganisms over an unspecified length of time and in undefined conditions.
Compostable: able to be broken down into carbon dioxide, water, and biomass within a specific time-frame under specific conditions. This can mean either home-compostable (at ambient temperatures and with a natural microbial community) or industrially compostable (under increased temperatures, humidity, and specifically formulated microbial conditions). Compostable material can be made from either bio-based or petro-chemical inputs. Compostable packaging is subject to certification standards in North America, Japan, and Europe.
Bio-based plastics: refers to where the material comes from rather than what happens to it after use. Conventional plastics are largely oil-based. Bio-based plastics are made – either wholly or partly – from polymers drawn from organic sources such as plants, microorganisms, and greenhouse gases (examples include corn, algae, yeast and CO2).