Around the world, environmental consciousness is at an all-time high.
Particularly since local and state governments started banning the use of plastic shopping bags, compostable bags have become a popular alternative for businesses and individuals. Made from organic materials and boasting renewable resource credentials, compostable bags are able to break down quickly and harmlessly and, in doing so, promise a more sustainable future.
So, what’s the decomposition timeline of a compostable bag? The short answer is – it’s complicated.
Firstly, as we know, not all compostable items are created equal. Some are better than others in terms of materials, adherence to composting certifications and dedication to responsible production practices. There are also other factors to consider, such as how the bag is disposed of, the composting environment conditions, and even the bag size.
These are a few of the contributing factors at play when determining how long it takes a single bag to decompose:
- Material makeup: A primary measure of whether an item is compostable is its material makeup. Compostable bags are made from a plant-based resin that is biodegradable and compostable. Derived from corn starch, sugarcane, or tapioca starch, it is designed to break down entirely in a composting environment, leaving no harmful residue or microplastics behind. Because We Care’s products are manufactured using two resin grades: the BF90 and KF90 series resins. These resins have earned endorsements for their effectiveness in breaking down in both industrial and home composting environments.
- Composting conditions: Compostable bags require specific conditions to break down properly, including the right mix of moisture, oxygen, and higher temperatures. While decomposition is relatively fast in the right conditions, the reality is these are often not met, leading to extended timelines, especially if sent to landfills. If disposed of with regular rubbish, compostable bags can exist for just as long as traditional plastic bags.
- Home vs. industrial composting: Some plant-based bags require disposal in an industrial composting facility to be able to break down fully. For this reason, it’s important to follow the instructions and information printed on the product, indicating whether it’s certified to break down in a home or industrial environment.
- Level of compostability: Due to their resemblance to regular plastics, bioplastics require a mechanism to ensure their quality and the authenticity of their claims. Globally, numerous product certifications and standardisations have been developed to combat misinformation about “green plastics”. Many of these certifications are region-specific to accommodate localised requirements and bio-management programs. Because We Care has a commitment to global sustainability and continues to pursue these certifications to meet the highest international standards in compostability.
Bags that are certified as compostable must comply with rigorous assessment criteria. Australia’s AS4736-2006 standard is one of the strictest measurements in the world. Its states that materials must have:
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- A minimum of 90% biodegradation within 180 days in compost.
- A minimum of 90% disintegration into pieces smaller than 2mm in compost within 12 weeks.
- No toxic effect of the resulting compost on plants and earthworms.
- No hazardous substances, such as heavy metals, above the maximum allowed levels.
- More than 50% organic materials.
- Ink: Many brands and companies use compostable bags as a marketing opportunity and choose to print logos or messages on the bags they give to customers. To be compostable, it’s essential that this print ink is non-toxic and organic-based. The ink used on Because We Care products is not only eco-friendly but has also been specifically developed for use on compostable products. This ensures that even the printing process aligns with our commitment to sustainability.
With all that in mind…how long does a bag take to decompose?
Depending on all these influencing factors, compostable bags can take anywhere from several weeks to several months to break down completely.
The important thing to remember when throwing away any compostable product is that it has the right environment to activate its organic breakdown. This process can be accelerated by using an industrial composting facility, which provides optimal conditions.
