Will Compostable Garbage Bags Actually Break Down in Landfills?

Compostable garbage bags might seem like an ideal way to swap out your plastic garbage bags for something renewable, but it’s important to make sure it actually makes a difference.

They’re made to be eco-friendly, but do they really benefit the environment?

The time it takes for a compostable container to degrade varies between materials and companies. The good news is that compostable bags will break down in landfills. But how quickly and well this happens relies on other factors. Most bags won’t break down very well in landfills because their design is meant to be sturdy enough to hold heavy contents. Instead, these bags will likely mummify like the rest of the garbage.

Are compostable bags really compostable?

A compostable bag is made from vegetable matter – like potato or corn starch – and is expected to break down within a time frame.

They differ from biodegradable bags, which don’t have time frames expected of them. “While everything that is compostable is biodegradable, not everything that is biodegradable is compostable”, says Biodegradable Products Institute.

While compostable bags will degrade into non-toxic materials, some are designed to only compost in specific conditions such as high-heat composting facilities. This is usually because the bags have to be designed so that they can hold heavy contents without breaking apart or the handles snapping. In landfills, these bags will eventually degrade but otherwise function similarly to non-recyclable bags – just without any toxic materials.

A study by Richard C. Thompson and Imogen E. Napper on the environmental deterioration of carrier bags found that compostable bags were better at degrading in 3 years than biodegradable, oxo-biodegradable, and conventional plastic. They note that when placed in soil, the compostable bag “was substantially weaker and could not hold the groceries”. However, no bags showed substantial deterioration.

Are compostable bags good for the environment?

Compostable bags are better used for holding organic matter like kitchen scraps, allowing you to transport the food to a compost bin or picked up by a composting company. When the bag begins to break down or if it gets any holes in it, you can add the bag to the compost list itself.

Degrading compostable bags requires heat, and often just a compost bin or the landfill won’t do. They may fall apart over time in a landfill, but they will still release methane just like any other organic matter.

If the bag finds its way into the ocean, there’s a chance that marine life may mistake it for food and choke on it. The bag won’t release microplastics in the ocean which eliminates another harmful feature of ordinary bags.

Are compostable garbage bags worth it?

If you’re buying compostable garbage bags, you should check the packaging for how best to dispose of them, or buy them for compost.

But these bags are definitely better in material to plastic alternatives and are good replacements when you’ve run out. You’ll have more impact by reducing waste, looking for reusable products to replace single-use products, and utilizing recyclable containers.