Biodegradable or bio-based? That is the question…
In our day and age, there are, thankfully, more and more products and brands that are focused on sustainability. This gives the consumer a variety of new sustainable options that have not been available in the past. With this ever-growing selection of environmentally friendly products, there is however also a growing confusion and misconception of how these sustainable products are produced and thereby how you recycle them. Depending on what materials a product is made of you will have different options of how to dispose of them.
When something is biodegradable the materials from which it is made, can under the right conditions break down and be used as a food source in the surrounding environment. It is a process that can take place in environments like soils, compost sites, water treatment facilities, marine environments, and even your own body.
The main confusion that occurs is the difficulty of understanding when a product is actually biodegradable and therefore can break down in nature. If we discuss terms such as renewable and bio-based materials it doesn’t necessarily mean that these will be biodegradable. Whether something is bio-based or made from renewable sources it refers to the raw materials of which these products consist of. Wood, corn, soybeans, etc. are all renewable or biobased feedstocks. Crops such as corn and soybeans are harvested year after year and are therefore considered a renewable source. These sources can be converted to products such as plastics and paper through the process of photosynthesis.
The American Society for Testing and Materials (ASTM) defines a biobased material as: a material is an organic material in which carbon is derived from a renewable resource via biological processes. Biobased materials include all plant and animal mass derived from CO2 recently fixed via photosynthesis, per definition of a renewable resource
It is important to know that even though a product is labeled “bio-based” or contains “renewable sources” it doesn’t necessarily mean that something is 100% based on renewable resources and therefore is biodegradable. Many products labeled with these terms, can also have petroleum-based materials or similar properties, which means that they won’t be biodegradable. But in the grand scheme of things, this is still reducing the overall amount of synthetic polymers in the product.
When is a product biodegradable?
It is tricky to know, but it all depends on the molecular structure of the material. Here it is necessary to contact the supplier of the product and ask if the product has been tested for biodegradability and compostability if it is not stated on the packaging.
The product needs to meet the ASTM Standards D6400 (for Compostable Plastics) or ASTM D6868 (for Compostable Packaging). IF they do, the materials will be able to (BPI paper on biodegradability):
- Disintegrate Rapidly During the composting process (so that there are no large plastic fragments will wind up on the composters screens when the process is finished)
- Biodegrade quickly under composting conditions.
- Not reduce the value or utility of the finished compost.
- Not contain high amounts of regulated metals.
Before you throw packaging, plastic, or anything else out for that matter, check the labels and the certifications on the package, it might be compostable – but then again, it might not.
Look out for the following labels:
- ASTM D6400
- ASTM D6868
- BPI certification symbol
These will give the product the stamp of approval that it has been tested and approved by a third-party laboratory for the ASTM Standards. The results will then have been confirmed by independent scientific analysis and you can with a calm conscious fill up your compost pile.