Home » Environmental » How Different Are Compostable Bags, Really?

Are Compostable Bags Really Compostable?

Collecting your food scraps and sending them to a composter instead of a landfill is one of the most impactful things each of us can do for the environment. This simple step reduces methane emissions from landfills and returns valuable nutrients to the soil. Whether you’re new to composting or a seasoned pro, choosing the right bag to collect your food scraps is crucial for both you and your local composter.

In this article, we’ll explore the true compostability of various bags on the market. We’ll provide you with easy tips to identify genuinely compostable bags and break down the pros and cons of the most common types. This will ensure you’re making an informed decision that benefits both your composting efforts and the environment. By the end of this guide, you’ll have a clear understanding of what to look for in compostable bags and how to make the best choice for sustainable waste management.

What is BPI Certified?

What is a compostable bag, and how can you identify it? In the world of compostable products, the BPI certification is what you want to look for. BPI compostable bags have been thoroughly tested to meet industry standards. These standards ensure that BPI certified compostable bags will completely break down in a commercial composting facility without leaving harmful residues. BPI certification guarantees that the product is safe for the environment and will decompose properly, making it easier for you to choose products that truly support sustainable waste management. Using BPI certified compostable products allows composters to know which products can be accepted into their facility, and allows you to be confident that you’re making a positive impact on the planet.

The next level up from BPI certification can be achieved through the Compost Manufacturing Alliance (CMA). Now that we know the product is capable of degrading properly without leaving anything harmful behind, we need to make sure it works in the real world. For this, CMA testing is done at a composting facility. There are several different types of composting methods that CMA can test for. Companies that have confidence in their products environmental benefits, like EcoSafe, will test all their products at every facility type. You can search for approved products here.

Greenwashing Examples

Unfortunately, the environmental industry is often cluttered with terms that can mislead the public into believing products are more eco-friendly than they actually are. Greenwashing companies will use words like “biodegradable” and “oxo-degradable” that sound similar to “compostable,” but they are not the same. While compostable products break down completely in commercial composting facilities, biodegradable and oxo-degradable items do not. These products can fragment into smaller pieces that are invisible to eye, but leave behind micro-plastics and harmful residues. As a result, they must be manually removed by composting facilities to prevent contamination of the entire compost batch. Understanding these distinctions is crucial for making truly sustainable choices and supporting effective waste management practices.

Should You Use a Compostable Bag?

When collecting food scraps and other organic materials, you have options. Your first choice is whether or not you want to use a bag at all. Choosing to not use a bag is perfectly acceptable as long as you’re committed to the cleaning that is required to keep the process sanitary. Without a bag in your kitchen or curbside bin, you will want clean your bins very regularly to prevent any remaining residue from rotting, becoming smelly, and attracting pests like fruit flies and rodents. Also, in colder climates organic waste can freeze in your compost bin and make it impossible to empty. We always recommend using a high quality, certified compostable bag to make the process easy, clean, and smell free.

What is the Best Compostable Bag?

There are a few categories of bags that are commonly used to collect food scraps:

  1. Commercial compostable bags
  2. Basic compostable bags
  3. Non-compostable bags

Commercial Certified Compostable Film Bags

Best compostability and performance

Premium compostable bags are going to compost perfectly and have BPI and every CMA certification to prove it. They are strong enough to hold a heavy load of compostable material, and leak resistant to avoid messes. EcoSafe bags hit all of these benchmarks with every product that we produce.

Made from compostable co-polymers, PBAT and PLA (derived from corn or other sugar generating plants like manioc), our bags are BPI and CMA certified compostable as well as extremely strong and resilient. The resin is made to be more resistant to rips, tears, and moisture. Due to this, our bags are strong enough to keep liquid in so you don’t have to worry leaving a disgusting puddle behind. When wet or hot food scraps are collected, the bag will remain strong with no leaks. In a compost facility, however, our bags break down just like the food scraps inside them. They will turn into nothing but water, a small amount of CO2 (this is produced by all food or products in the composting process), and humus – a nutrient-rich organic material.

Other Compostable Bags

Compostable but weak performance

Paper bags

The other product that can be used to collect your organic waste is a lined paper bag. You may not realized that the paper bags used for this are lined, but they all are! A paper bag without a lining will not have any resistance to water. As a result, most paper bags are lined with cellulose. Cellulose is a natural product that is inexpensive and gives a moderate amount of protection from leaks. It does nothing to add strength or durability to the bag. Natural fiber bags do two things really well; compost and use sustainable materials. Where they fall short is in performance. These are usually in form of kraft paper bags that don’t work in bins (even when lined with compostable cellulose), and react very poorly to wet organics. However, in situations where their limitations can be accommodated, these bags live up to their environmental claims very well.

Low-cost compostable film bags

A cheaper compostable film bag will have a very similar chemical make-up to a premium bags except the formula is tweaked to reduce the cost of the resin. This decreases the strength and leak resistance of the bag. Along with that, these bags will often have filler elements added in to further stretch how many bags can be produced. To top it off, many will label it as “Corn-based” to increase the appearance of the bag as being natural. This is a bit of a misnomer – all compostable bags have a compostable polymer as their base, with a lesser percentage of a renewable resource such as starch or PLA making up the balance. These ‘corn-based’ alternatives contain starch, which has hydrophilic properties. The result is a bag that absorbs the moisture from your organic waste and will weaken, leak, and break much more easily.

Non-Compostable Bags

Not accepted at compost facilities

Do not use non-compostable bags to collect food waste. Plastic, “biodegradable,” and “oxo-degradable” bags are considered non-composable and should never be used or sold for organics collection.

Using non-compostable bags, such as plastic, biodegradable, and oxo-degradable bags, poses significant environmental dangers. These bags do not break down fully in composting facilities, leading to contamination and the need for manual removal. Plastic bags can persist in the environment for hundreds of years, contributing to pollution and harming wildlife. 

Plastic bags are cheap, durable, and responsible for the environmental epidemic that is choking the earth’s oceans and environment. Many cities are banning these bags because of the horrible impact they are having on our way of life and the planet we occupy.

Biodegradation is a natural process that every material on earth goes through, even plastic. The problem with this term is that it does not set a timeline for the product to degrade, and doesn’t account for what it degrades into. Biodegradable and oxo-degradable bags may sound eco-friendly, but they often only break down into smaller pieces, creating microplastics that are harmful to ecosystems. Recognizing this, many laws are being enacted to limit misleading terms like “biodegradable” that have been used for greenwashing. These regulations aim to ensure clearer labeling and promote truly sustainable alternatives, helping consumers make more informed and environmentally friendly choices.

Now that you know the difference between your bag options, check out all of our EcoSafe® products and programs that can help you do your part for the environment.

Food loss and waste occur at each stage of the supply chain. The biggest proportion (about 37%) happens in the home.

ReFED, 2021