Every year, humans across the world produce approximately 400 million tonnes of plastic waste—half of which is single-use, like plastic shopping bags. This plastic finds its way into our rivers and, ultimately, oceans—which, at last estimate, house somewhere between 75 and 199 million tonnes of plastic.
This is terrible for the wildlife that live in these habitats—but it’s bad for human beings too. Because plastic doesn’t decompose but, rather, breaks down into tiny particles called “microplastics”, this plastic waste is entering our bodies through inhalation and absorption—introducing chemicals like methyl mercury, plasticisers and flame retardents into our bodies.
Replacing single-use plastic bags with compostable bags could be one way to dramatically reduce the plastic waste we produce—and resolve some of the associated health and environmental impacts.
But how, exactly, are compostable bags better? Well, that’s what we’ll discuss in this article.
Specifically, we’ll talk about:
The war on single-use plastic
The role of compostables
What are compostable bags?
How does the composting process work?
How are compostable bags better for the environment?
How to find the most environmentally-friendly compostable bag
The war on single-use plastic
To curb our addiction to plastic, many governments across the world are banning single-use plastics. In North America, the Government of Canada has a goal of reducing the country’s plastic waste to zero by 2030. The first phase of this journey launched in December 2022, when it implemented a country-wide ban on the manufacture, import and sale of single-use plastic products like checkout bags, cutlery, foodservice ware made from or containing problematic plastics, ring carriers, stir sticks, and straws.
In the United States, many states and territories have banned single-use plastics in varying capacities. Fourteen states and territories have banned single-use shopping bags, while many have gone beyond just bags to include carryout containers, polystyrene (Styrofoam) and straws.
The role of compostables
While these bans are unquestionably a step in the right direction, they also create a gap in the marketplace. In the case of single-use bags, for instance:
- Shoppers who forget their reusable shopping bags at home must buy more reusable shopping bags—plastic products they don’t need.
- Individuals who used single-use plastic bags to collect pet waste—or line their garbage bins—must now buy more plastic bags to do the same task.
- Certain single-use plastics, such as produce bags and plastic food packaging, aren’t covered by many of the bans.
Fortunately, compostable bags offer a solution to many of these challenges.
What are compostable bags?
Compostable film products—which include things like liners for compost bins, shopping bags, food service gloves, cling wrap and produce bags—are products that can be composted in community and commercial compost programs.
They’re made of compostable resins which are typically composed of compostable biopolymers, PBAT and PLA—allowing them to decompose as easily as a banana peel.
It’s important not to confuse the term “compostable” with terms like “biodegradable”, “oxo-degradable”, or “photo-degradable”. Products that use these terms often include polyethylene—so while they may break down into smaller pieces of plastic, they don’t decompose completely like a “certified compostable” product would.
How does the composting process work?
While compostable bags can decompose completely, they can only do so in a commercial composting facility—because it takes a little bit of work, and the right environmental conditions, to break down the resins.
First, the bags need to be ground down into small pieces—which accelerates the composting process. From there, they require microorganisms which can only be found in a compost pile. These microorganisms emit enzymes which break the material down further. Lastly, the bags require a level of high heat to be distributed consistently over a specific period of time.
In the right environment, a certified compostable bag should decompose completely within 10 to 45 days, depending on the composting facility’s equipment. It’s only by-products are 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).
How are compostable bags better for the environment?
In areas that offer commercial composting, compostable bags offer three key benefits:
Compostable bags support the phase-out of single-use plastic
As more jurisdictions ban single-use plastic bags, shoppers are encouraged to use reusable plastic woven bags. The thing is, research indicates that most people own plenty of reusable shopping bags—in many cases, more than 20—but they often forget to bring them out when they go shopping.
At this point, shoppers have limited choices. They can purchase a new reusable bag they don’t need—which comes with its own environmental impact—or perhaps purchase a paper bag (which are notoriously terrible for carrying heavy groceries, and are often lined, negating their compostable potential).
Compostable shopping bags are just as strong—and effective—as single-use plastic bags. If shoppers were given this option, they could carry their groceries home and then use the bag to line their compost bin or (depending on their municipality) collect pet waste.
This is just one way compostable film products could support the phase-out of single-use plastics, but there are many others. For instance, compostable produce bags could be used to replace the thin plastic bags that are currently offered in produce aisles, or that are used as an extra layer protection for packaged raw meat in grocery stores.
Compostable cling wrap could help reduce the plastic used in food packaging and storage—and compostable food service gloves could dramatically reduce the plastic waste created in both grocery stores and restaurants.
Compostable bags encourage behaviour change
Offering a curbside composting program is one thing—but getting people to participate? Well, that’s quite another.
In many municipalities, existing social behaviours and habits are so ingrained that it can be difficult to encourage households to divert their food waste from the garbage to their green bin.
Part of this solution involves education—it takes a concerted effort to explain why composting matters, and how to properly compost (and avoid contamination). But composting also needs to be as easy and convenient as possible—which is where compostable liners come in.
While it’s possible to throw food waste directly into an under-sink, countertop, or curbside bin without any form of liner, that gets messy—fast. Many paper bags are lined with a non-compostable coating and, as a result, aren’t accepted by many commercial composting facilities. Non-lined paper bags or newspapers are prone to breakage and leakage—which can also deter some people from composting.
Compostable bags, meanwhile, are leakproof and accepted by many composting facilities. Because they offer a clean composting experience, people are more inclined to compost when using compostable liners. In fact, research shows that when combined with strong bylaws and education programs, compostable liners can lead to above-average municipal composting rates—well above 80%.
Compostable bags reduce the resources needed for commercial bin cleaning
Just as composting can be a rather messy undertaking in residential areas, it can also get kind of gross in commercial settings—like restaurants, grocery stores and other places that dispose of food waste.
In most cases, municipal curbside composting programs don’t visit these commercial areas—so these customers rely on private haulers to take their organic waste to the commercial composting facility. While residential homeowners are responsible for cleaning their own bins, the haulers are responsible for cleaning commercial bins.
Traditionally, haulers have relied on a handful of options to remove the icky black buildup that inevitably coats every green bin—pressure washing, automatic cleaners, bin swaps or cleaning services. The challenge is that each of these options comes with significant environmental impacts, time requirements and costs—and while they all resolve the messiness associated with composting, they don’t eliminate it all together. As a result, commercial composters can still find their bins full of undesirable odors, insects and pests from time to time.
Compostable liners—designed to snugly fit commercial composting bins—can resolve this challenge. Not only do they neatly contain all organic matter (and completely eliminate associated messes) but they also come with a lower environmental footprint, are less time-consuming and less costly than alternative options.
How to find the most environmentally-friendly compostable bag
Unfortunately, navigating the compostable bag market is a lot more difficult than it should be. To find a bag that works for your needs—and will easily decompose in your local commercial composting facility—it can be helpful to pay attention to three things:
Certification
If you’re looking for a trustworthy compostable product, the BPI certification mark is essential. To obtain it, a product must go through rigorous, third-party lab tests to ensure it meets specific technical standards that will ensure it’s capable of decomposing in a commercial composting facility. Look for BPI-certified compostable bags when you shop.
It can also help if a product is Compost Manufacturing Alliance (CMA) approved. The CMA conducts field tests on compostable products to ensure they can decompose in a real-life commercial composting setting. When a CMA logo is placed on a product, it will identify which types of environments it’s been tested and approved for. It will also require the product to be tinted a specific colour—typically green or brown—so composters can quickly identify whether a product is fit for their type of composting facility.
Strength
You want your compostable bags to be as strong and leak-proof as possible—so they won’t rip or leak when carrying heavy and/or wet loads. A bag’s strength ultimately comes down to its resin.
All compostable bag resins are a mixture of petroleum products and organic sources like corn starch. The petroleum products are necessary to increase a bag’s strength and water resistance, so while some bags may boast a higher level of organic materials, this actually makes the bags less durable (and cheaper to produce) without positively impacting their compostability.
Reliability
For a compostable liner to work as effectively as possible, it needs to snugly fit your composting bin. At EcoSafe, we offer compostable liners in a vast range of sizes—for many different types of composting bins. To help you find the best bag to fit your needs, we offer right-fitting tools that allow you to conveniently input the dimensions of your bin.
Frequently Asked Questions
Here are a few frequently asked questions about why compostable bags are better for the environment.
1. What are compostable bags made of?
Compostable bags are made from compostable resins which are typically composed of compostable biopolymers, PBAT and PLA.
2. Are compostable trash bags the same thing as compostable bags?
No, compost trash bags are trash bags made out of compostable materials.
Sometimes, compostable trash bags may be made of renewable resources like cornstarch, sugarcane, or potato starch. Unlike plastic bags, they can break down naturally in a matter of weeks or months, leaving no harmful residues.
3. What can I put in a compostable bag?
Compostable bags are suitable for collecting food scraps such as fruit and vegetable peels, eggshells, coffee grounds, meat and bones, as well as food soiled papers (like napkins). You can also place yard waste such as leaves, twigs, and grass clippings within the bag. You should always check what items your local composter accepts as they can sometimes vary. These bags are designed to disintegrate with the compostable material at the appropriate facility.
4. How do I use a compostable bag?
When using a compostable bag, it’s essential to avoid overpacking it. Place it in a compost bin, and add your food scraps and yard waste. The bag will remain strong while using it, but when exposed to the heat and organisms present in an industrial composting facility, it will break down along with the compostable materials, leaving behind nutrient-rich fertilizer for your plants.
5. How do I store a compostable bag?
Compostable bags should be stored in a dry, cool place away from sunlight. Exposure to heat and sunlight can cause the bags to break down prematurely. It’s also essential to use them within the expiration date of their purchase to ensure their effectiveness.
6. Are there any drawbacks to using compostable bags?
Compostable bags are not perfect, and they have their drawbacks. They require a composting environment to break down, which means they won’t decompose in a regular trash can, or in your home compost pile.
They may be more expensive than your common plastic trash bag, but plastic bags cannot be used to collect compostable materials, and compostable bags are by far the easiest and cleanest way to collect organic waste.
Research before you buy
Despite their host of environmental benefits, compostable bags aren’t right for everyone. To be a better environmental option, compostable bags need to find their way to a commercial composting facility. They can’t decompose in landfills and, if they blow away, they run the risk of polluting lakes, rivers and oceans like their single-use plastic counterparts.
Unfortunately, many jurisdictions across North America still don’t have composting programs—and of those that do, many commercial facilities can’t effectively process compostable bags. While things are changing on this front, it’s important to determine whether compostable bags are accepted in your region before purchasing.
If they are, and if you’d like to learn more about EcoSafe’s wide range of compostable products, find them here.