Do Compostable Bags Live Up To Their Name?
Matthew Moi
David Thompson Secondary
Floor Location : J 109 V

Plastic pollution is a big problem on our planet so many people are switching from plastic to compostable products. But do these products live up to their name? In this project, five samples of compostable products were buried in soil for a 7 week period inside of a mini greenhouse. These compostable products were homemade potato bioplastic, paper lunch bags, Bag To Earth compostable paper bags, Biobag compostable plastic bags, and Ziploc compostable plastic bags. After the 7 week period, the samples were taken out of the soil and observations were made on their decomposition.

Each sample was observed under a microscope and the degradation of the samples was compared to the “control” samples and to the other types of products. The potato bioplastic almost fully disintegrated into the soil, lost its original blue colour, and broke down into small pieces. The paper lunch bag broke down into small pieces, was not very intact, and had a lot of excess soil stuck on it. The Bag To Earth had mold growing on its surface and it was ripped in many places. The Biobag’s colour slightly changed to a lighter shade of green and its texture was different to its “control” version. The Ziploc bag had barely any changes when compared to its “control” version, besides having little excess soil stuck on it after brushing.

The results support the hypothesis which is that the homemade potato bioplastic degraded the most and the commercially-made compostable plastic bags degraded the least. This is due to the homemade potato bioplastic being made out of mostly organic materials. This is also due to the commercial compostable plastic bags being made out of plastic with chemical additives added in the products.

In conclusion, organic materials degrade faster than commercially-made compostable plastic materials with chemical additives. Hopefully the findings will raise consumer awareness when people purchase products that are labelled as compostable. Companies will hopefully improve their compostable products that are more environmentally-friendly. Future improvements for this project include a longer duration of the experiment and the use of a wider variety of compostable products.