Compostable v. Biodegradable

by Elaia Vardanyan



There can be a lot of confusion with all of the different labels on eco-friendly products. Today, I’d like to highlight the differences between compostable products and biodegradable products to help you decide which is best for your needs. All compostable products are biodegradable, but not all biodegradable products are compostable. This alone can be confusing. Let me explain.


All compostable products are considered biodegradable because they will break down, but only under the controlled conditions required for compost. Biodegradable just means that the product will break down naturally over time, but may not be appropriate for your compost chemically. Compostable products break down into just humus; the dark organic matter you hope for when your compost is ready for the garden. However, biodegradable products break down into a number of byproducts. Let’s focus on biodegradable plastics to dive into the specifics.


Biodegradable plastics are the most common product when you see the label has been marked ‘Biodegradable’. For this plastic to be compostable it cannot pose harm to plants or animals. These plastics do not always do well in personal composting and are more commonly broken down in industrial facilities designed with the necessary controlled conditions. That’s because it can still take much longer to break down, albeit less time than Petroleum based plastics. The issue we face is that there are not enough of these facilities and so for most people we must still throw it into the garbage. 


These bioplastics themselves have no carbon print, however this does not take into account the carbon produced by the facilities necessary to produce, distribute, or break them down. It has less carbon emission than traditional plastics but is still not optimal for waste reduction. These plastics fall into the #7 plastics category which is home to all “other” plastics with no process to recycle or compost. If they are compostable it will explicitly state ‘compostable’ next to the #7 symbol as well.


To wrap things up: If your product is marked ‘compostable’, you can toss it in your compost bin. If it’s a #7 plastic with ‘PLA’ or is only marked biodegradable it isn’t recommended for your compost and should be disposed of in the garbage bin. It will still take years to break down in a landfill despite its “eco-friendly” labeling. If you are going to buy plastic, it is best to buy one that is recyclable in your area instead. “Research, published in 2015, estimated that 8 million metric tons of plastic ends up in the oceans every year. That is the equivalent to five grocery bags of plastic trash for every foot of coastline around the globe.” The same study also showed that around 91% of plastic is not recycled. Let’s do our part in the world’s largest cleanup, one compost bin at a time.



References

Biodegradable Plastics: Standards, Policies, and Impacts - PMC (nih.gov)

Grappling with the infamous #7 PLA recycling code - McGill Compost

A Whopping 91 Percent of Plastic Isn’t Recycled (nationalgeographic.org)