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Burning Question: What is the difference between biodegradable and compostable?

A student on the Auraria Campus asked, “what is the difference between biodegradable and compostable?”  


What's the difference?


In short, anything that is compostable is biodegradable, but not everything that is biodegradable is compostable (BPI World). A product must be able to break down into organic materials that can offer nutrients to the soil and plants around it to be compostable (Western Disposal). In addition, it must be third party certified by BPI (Biodegradable Products Institute) or CMA (Compost Manufacturing Alliance). Biodegradation refers to the process of microorganisms consuming organic carbon in a material. While it is not incorrect to refer to compostable products as biodegradable from a technical standpoint, consumers should not assume a product can be composted if it is labeled as biodegradable.  


Products marketed as biodegradable are not held to the same standards or certification process that compostable products are and can still be harmful to the environment. The term “biodegradable” is vague when used to market products, as it does not indicate how long it takes for a material to break down or in what environment. A biodegradable product can break down in 5 years or 500 years. Even after degrading for decades, biodegradable products can break down into microplastics, which can contaminate the compost stream and soil systems if disposed of incorrectly. To find out if a product is certified compostable, you can check BPI’s or CMA’s certified products tools.


Colorado legislation 


To combat confusion between compostable and biodegradable products, the 2024 Compost Labeling Act requires food service products and plastic products labeled as compostable that are sold or distributed in Colorado to be certified compostable and clearly marked as such.  Plastic products can no longer contain words such as “natural”, “biodegradable”, “degradable”, and “decomposable” (CDPHE). These words are all forms of greenwashing.  


Greenwashing 


Greenwashing means intentionally mislabeling products with words like “eco-friendly” or “green” (and the ones listed above in the Colorado law) which do not have standard definitions (UN). It can also include claiming that a company is moving toward zero waste when no plan is in place, being intentionally vague about materials used, or emphasizing an environmental attribute while ignoring other impacts (UN). Companies may use green packaging or images of leaves to make customers feel better about purchasing their products, but unless a product is certified compostable by BPI or CMA, it will not break down properly in a compost system.  


Biodegradable does not mean compostable, so make sure the products that you buy are certified compostable by BPI or CMA. The Compost Labeling Act in Colorado can help hold companies accountable, but you can too by avoiding products that are greenwashed. 


Written by: Peri Muellner


References


BPI. (2026). Biodegradable vs. compostable. BPI. https://bpiworld.org/biodegradable-vs-compostable 


Colorado Department of Public Health and Environment. (2026). The Compostables Labeling Act. https://cdphe.colorado.gov/hm/standards-compostable-products 



United Nations. Greenwashing – the deceptive tactics behind environmental claims.  https://www.un.org/en/climatechange/science/climate-issues/greenwashing 

 

Western Disposal. (2026). Compostable vs. Biodegradable – what's the difference? https://www.westerndisposal.com/compostable-vs-biodegradable-whats-difference/ 

 
 
 
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