What is the Difference Between Biodegradable, Degradable, and Compostable?

woman holding plastic bag

Do you know the difference between biodegradable, degradable, and compostable?

With the eco-friendly movement, oftentimes these phrases are used interchangeably, but they mean different things. Why do companies use these words interchangeably? It's to make themselves sound more environmentally friendly, even if they are not.

Here, we explain the differences between each one so you have a better understanding and can make better decisions when it comes to purchasing and using reusable shopping bags.

Compostable materials are the only ones that break down once they are put in the landfill. The compostable materials don't have microplastics like we see in other common household materials, such as disposable plastic bags from the supermarket. Since reusable shopping bags don't have these harmful microplastics, they are cleaner and more environmentally friendly than their plastic counterparts.


Let's start with biodegradable, which means bags are made from PLA, or a mixture of bioplastics. These plastics include PVC, polystyrene, polyethylene, and polypropylene. However, this is not all bad. Most bags made from biodegradable materials have an added compound that assists in the degradation process. Furthermore, the plastic is also broken down by microorganisms, like fungi and bacteria. Once these plastics are broken down, all that is left is microplastics, which end up in the environment.

There three stages of biodegradability, which are:

  • Biodeterioration
  • Biofragmentation
  • Assimilation

Biodeterioration modifies the properties of the material, which can be the chemical, physical, and mechanical properties. Next is biofragmentation, which bonds with polymers. Lastly, the result of biofragmentation is the integration of the microbial cells, which is called the assimilation stage.


Degradable means the object will break down over time. It doesn't have to specify any time, which means it could be a number of years before the material eventually degrades. Since this is the case, pretty much everything is considered degradable. Even if bags are made from plastics, they can still be considered degradable. This is because the manufacturer adds a chemical to the plastic material to help it degrade over time. Yet, just like biodegradable materials, degradable materials leave microplastic behind, which stay in the environment.


Compostable materials are typically made of plant materials. When they break down, the components left behind are non-toxic. Therefore, there are no microplastics left behind.

When compostable materials are put in the landfill, they act just like plants composting in the forest, or the natural environment. Since they are more natural, the material left behind allows plants to grow, which is more environmentally friendly.

person holding compostable material

The biggest difference between compostable material and biodegradable material is that composting is human-driven where biodegradable naturally occurs. This means all compostable materials are biodegradable, but not all biodegradable materials are compostable.

For example, if you put compostable material in water or land, it breaks down in a short period of time because it is exposed to microorganisms and oxygen. Furthermore, if you want to be more eco-friendly in your home, you can use composted material to replace fertilizer. Put food scraps in an organic waste bin. After a while, the material composts and you can use that on the soil. Over time, your soil quality will improve because of the natural compounds from the composted food.

Why is it Important to Know the Difference?

Every year, 90 percent of the trash floating in the ocean, lakes, and rivers is made out of plastic. That is a lot of waste polluting the natural waterways. Since there is so much waste in these areas, 100,000 marine mammals are killed every year because of the trash in the ocean.

Plastic bags don’t degrade right away. In fact, it takes over 1,000 years for those bags to degrade. Remember all the plastic bags you get from the store or takeout restaurants? There is a good chance they are still sitting in the landfills. On average, the entire world uses two million plastic bags every minute. That amounts to 500 billion plastic bags used around the globe each year.

How Should You Dispose of These Products?

If you put biodegradable material into landfills, chances are they are covered with trash in a short amount of time. The bacteria that break down biodegradable products can’t survive underneath this pile of trash because there is not enough oxygen. Therefore, biodegradable products breakdown without oxygen, which is anaerobically. The process of anaerobic breakdown creates methane gas, which is a greenhouse gas that harms the environment. Methane gas is actually 26 times more potent than carbon dioxide.

To properly dispose of biodegradable products, you should send them to a recycling plant or put them in a commercial compost heap. Another option is to look for a biogas plant. A biogas plant creates methane from biodegradable products to generate electricity. However, these may be difficult to find in your area.

When it comes to compostable material, you can put them in a compost bin. The microorganisms reach high temperatures, which breaks down the materials fast. Don’t put compostable materials in the recycling bin because it can contaminate the recyclable materials. Instead, use a compost bin for best results.

Tips to Reduce Waste

Now that you understand the differences, you are probably wondering how to reduce waste. Try to avoid using single-use plastic bags. Reusable shopping bags or canvas tote bags are good replacements for plastic retail shopping bags.

woman holding plastic bag

Learn how to compost and keep compostable products out of your recycling bin. It’s easy to get started with composting and you really don’t need any special tools.

Replace your single-use products with reusable products. This includes water bottles, canvas tote bags, reusable shopping bags, and other utensils. Start small so you don’t get overwhelmed, and in no time you will have an eco-friendly household.