Although terms like: biodegradation, biodegradable, and compostable are becoming more common, they are often used incorrectly, and are often misunderstood. Almost everything is biodegradable with enough time (which may be thousands of years), but this is not the same with the term ‘compostable’. Although you will see products claiming to be 75% compostable or highly compostable or similar, this in practice, means they are not compostable. In these products, the percentage that cannot be composted will contaminate the entire composting process. For a product to be compostable, it must be fully or wholly compostable. Fortunately there is a standard that can help us to understand if a product is wholly compostable.
The European EN 13432 standard defines the characteristics a material must have for it to be ‘compostable’. In other words, that the product can be recycled using this special form of treatment. A definition of the criteria for composting is important because materials that cannot be composted (traditional plastics, glass, materials containing heavy metals etc) will have a negative impact on the final quality of the compost and make it unusable. This standard is a reference point for manufacturers, public authorities, composting operations and consumers. Australia has a similar standard AS 4736-2006. This provides a definition for biodegradable plastics suitable for composting and other microbial treatment. New Zealand is in the process of creating a similar standard.