Pros and Cons of Compostable Garbage Bags

We often hear about the importance of reducing trash, but what about the bags we throw our trash in? Here's a primer on some of the greener alternatives to plastic trash bags.

Typical trash bags are made of strong, resilient polyethylene, the most widely used type of plastic in the world. These bags are often derived from oil or natural gas and remain in the environment for hundreds of years or more. "Compostable" and "biodegradable" bags are often marketed as environmentally friendly alternatives.

Although the two terms sound interchangeable, they are not quite the same. If the bag is biodegradable, it means that when placed in a completely natural environment, it will eventually start to degrade over time with the help of biological helpers such as bacteria or fungi.

While certainly a good idea on paper, the term doesn't say how long the process takes to happen, so it's a bit vague and leaves room for being abused or misused as "greenwashing".

If a bag is compostable, it means that it will decompose under a very specific set of controlled conditions within a certain period of time without leaving any toxic residue in the environment. While the term can also be misused, it is more strictly regulated.

Compostable bags are usually made from plants like corn or potatoes rather than petroleum. If a bag is certified compostable by the Biodegradable Products Institute (BPI), it means at least 90% of the plant-based material breaks down completely within 84 days in an industrial composting facility.

All BPI-certified products are tested in independent, accredited testing laboratories. These test results are then evaluated by third-party technical auditors. Nearly 12,000 products are currently third-party certified by BPI with its signature leaf and tree seal.

If you're looking for a trash bag that can be quickly returned to earth when you're done with it, then this is the airtight bag you need to be looking for.

So are compostable trash bags good for the environment?

The answer to this question is not as simple as you might think, because compostable bags can only be composted in certain places.

Industrial composting facilities create the ideal conditions (heat, humidity, and good ventilation) for these bags to decompose quickly and leave no traces.

It's worth noting, though, that not every industrial composting facility will accept these bags, and some facilities are perfectly fine with compostable bags. Others don't want it because it could open the door to non-compostable bag pollution.

So check with your local composter before sending them bags they can't use. If they don't accept them, they'll have to ship them to a dump where they don't degrade quickly.

Here's where things get complicated: When a compostable bag ends up in a landfill, it lacks the oxygen it needs to decompose. Instead, it just sits there and can hang around like a plastic trash bag for a long time. (Although requiring fewer fossil fuels, to begin with, creates an environmental advantage.)

This means that, in order to function the way they are designed and marketed, compostable trash bags actually need to be filled with compost (organic food and yard waste), not trash (everything else).

They also need to be disposed of properly: studies have shown that if they end up in litter, they don't biodegrade in the natural environment, at least not for three years.

Most likely, no. Home composters often find these bags tricky if not impossible to use: Because they're designed for industrial sites, they take a long time to break down in backyard piles (if they do at all).

- Rapid decomposition in industrial composting facilities

- Not made from fossil fuels

- Often made from resource-intensive crops such as corn or potato starch

- Usually thinner than plastic bags, they may leak if overfilled. (Storing it in the refrigerator will help prevent this.)

- Tends to be more expensive than traditional plastic bags

Compostable trash bags are made from plants rather than petroleum, but they usually only break down under very specific conditions. At the end of the day, the greenest thing you can do with your trash is to throw away less stuff (and recycle fewer bags) in the first place. Start reducing household waste with these folksy tips.

The above have introduced some advantages and disadvantages of compostable bags, if you want to know more or want to buy compostable bags, please contact us.

Torise Biomaterials is a custom compostable and biodegradable products manufacturer. Since August 2010, we have been developing a full range of sustainable alternatives to traditional plastics. Our Torise products are made from natural resins derived from plant starches, vegetable oils and compostable polymers that are easily consumed by microbes in the soil.

All of our products have international authoritative certifications such as EN13432 (Din Certco), OK Compost, OK Compost HOME (TUV Austria), ASTM D6400 (BPI), AS4736 and AS5810 (ABA).

From our raw materials to inks, to finished products, you can be confident that anything we make will break down in the process and won't harm the environment!