Compostable and Biodegradable Trash Bags: Should You Use Them?
That white, black, or even vanilla-scented trash bag might make trash day a little easier but it’s also sending our planet to the landfill.
We’re looking at you, plastic trash bags.
Plastic trash bags are generally made with low-density polyethylene (AKA fossil fuels), which takes hundreds of years to decompose and releases harmful microplastics.
Recently rubbish-disposal trends have seen an explosion of compostable and biodegradable trash bags.
But, just as all “trash” isn’t equal (read: compostables, recyclables, and online thrift store donations), we shouldn’t view all “Earth-friendly” trash bags as equal either.
Albeit similar terms, compostable and biodegradable mean very different things.
So where does this leave compostable and biodegradable trash bags?
Well, we’re going to sniff through the trash to find out.
Plug your noses and let’s get into the compostable vs. biodegradable trash bags debate (Hint: there’s an even better option!).
*This post contains affilate links
QUICK LINKS FOR COMPOSTABLE AND BIODEGRADABLE TRASH BAGS
1. WHAT ARE BIODEGRADABLE TRASH BAGS?
Before we dive into biodegradable trash bags, here’s a quick refresher of what it means to be “biodegradable.”
According to Merriam-Webster, biodegradable is that which is “capable of being broken down especially into innocuous products by the action of living things (such as microorganisms).”
Sounds innocent enough, right?
That is, until you realize that plastic being broken down into microplastics is not an Earth-friendly way to dispose of household waste, dog poop, or, anything really.
In fact, if it leaves microplastics behind, by definition it’s not even biodegradable, but rather plain old degradable.
For something to be biodegradable, it must leave behind only natural elements (the “innocuous products” of Webster’s definition). Plastic, no matter how small, is certainly not that.
What are biodegradable trash bags made of?
While “bio” might elicit images of nature and plants (which is how some biodegradable trash bags are made), biodegradable plastic is also a thing.
This is typically just petrochemical-based plastic manufactured in such a way that exposure to certain things will help it break down faster. You might see words like “photodegradable” or “oxo-degradable”, which means trash bags that break down in sunlight or air, respectively.
Both mean living organisms (bacteria, fungi, etc.) aren’t involved, making these bags a worse alternative to conventional plastic trash bags. When they enter our environment, they’re just as bad as regular plastic bags (despite their much higher price tag)!
Another problem with biodegradable plastic is that it cannot be recycled like other types of plastics—and will actually contaminate otherwise perfectly sorted recyclables.
What’s a bioplastic?
There’s also bioplastic, which may be blended with petroleum-based plastics in a biodegradable kitchen trash bag or a compostable trash bag.
These are usually made with plant-based and renewable materials, like corn (polylactic acid/PLA), grains, sugarcane, starches, or vegetable oils.
To make a bioplastic like PLA, the sugars found in sugarcane, corn starch, or cassava are immersed in a hot water-sulfur dioxide solution so that the different components (fiber, protein, and starch) become “available”.
These compounds are then ground so the starch can be separated into what ends up in biodegradable bags.
In the end, it’s essentially a long chain of carbon molecules, much like plastic (especially polyethylene).
Another type of bioplastic is PHA, or polyhydroxyalkanoate. This is made from genetically-engineered microorganisms that consume organic materials to produce carbon reserves.
At the end of the process, the microbe-made PHA has a plastic-like structure that can be harvested for trash bags—in addition to things like food packaging and medical products.
Mater-Bi is another plant-starch bioplastic and cellophane (which you may have heard of) is a wood-based bioplastic.
One benefit of all bioplastics is that they are free of toxins like bisphenol A (BPA).
2. WHAT ARE COMPOSTABLE TRASH BAGS?
Compostable trash bags are next level biodegradable trash bags.
Again, it’s helpful to refresh what compostable means (or take a deep dive into some lesser known composting facts, if you like).
According to Cambridge Dictionary this time, compostable is “something that can be used as compost when it decays.”
Like biodegradable, compostable materials can fully break down into natural elements, but they can also become something that’s beneficial for the soil.
They also have a tighter time restraint in which to do so.
For something to be legally biodegradable, it must break down in a “reasonably short period of time” (which as you might guess, leaves a LOT of room for interpretation), whereas compostable products must break down in 12-24 weeks.
Unfortunately, compostable bags still aren’t as “green” as they may seem based on this basic definition.
How do compostable trash bags work?
Compostable trash bags, first and foremost, have to meet certain criteria to be indeed deemed “compostable.”
Most commonly, this means meeting the three basic provisions of the ASTM D6400 standard:
- The product must experience physical disintegration, to the point that it is not “readily distinguishable” from the finished compost product.
- Actual biodegradation must take place, meaning that microorganisms consume the product at a rate similar to other, well-known compostable materials.
- The products left at the end of the composting process must not harm or diminish plant growth.
Essentially, a compostable material must “reach or exceed 90% conversion of the carbon within the material into carbon dioxide (CO2)” during a specific time-frame (usually 180 days).
This means that just 10% will return to the soil as compost and the majority will enter our atmosphere as a greenhouse gas (yikes).
This is all based on perfect compostability, using a high-heat industrial composting facility, rather than an indoor compost bin for example that can’t reach such high temperatures.
This brings us to perhaps the most important aspect of compostability: proper disposal.
How to dispose of compostable trash bags?
Using compostable trash bags doesn’t give you free rein to dispose of it however you please and still have it be eco friendly.
Your green compostable trash bag isn’t so “green” when you consider that, if sent to landfill, the anaerobic (AKA absent oxygen) conditions will lead to a release of methane—a greenhouse gas with 100-year warming potential 25x higher than that of carbon dioxide.
That said, properly composting a compostable trash bag (so that it can break down aerobically via naturally occurring microorganisms) is critical.
Otherwise, it’s arguably worse than a plastic bag.
Put another way, compostable bags need five things: microbes, moisture, oxygen, heat, and time. Without these, they could end up either not decomposing, or releasing harmful greenhouse gasses into the environment.
That’s why a waste stream dedicated to that type of waste is necessary
Fortunately, more industrial composting facilities are popping up around the globe, along with dedicated food and yard waste bins for curbside pickup.
If you don’t have the good fortune to live in an area with curbside composting, find a place to send your bagged food scraps using the Find A Composter website (US only).
Note that many composting facilities are classified according to accepted feedstocks which vary by state, so be sure to look for those that accept mixed solid waste (usually Class I).
Alternatively, the best compostable trash bags can be composted in a backyard compost bin!
There aren’t any home compost standards in the United States, but as a general rule of thumb, complete degradation in 90 days should happen if the internal temperature of the compost heap is between 90° and 140° Fahrenheit (meaning that it should be at least three feet deep and wide).
What are acceptable compostable trash bags?
There are a few things to look for when it comes to small compostable trash bags that are actually compostable.
Check the packaging for the following:
- The Compostable Logo (from BPI, The Biodegradable Products Institute): The logo indicates that the product meets either ASTM D6400 (includes bags) and/or ASTM D6868 (for packaging).
- TUV AUSTRIA: They provide three different certifications, OK COMPOST HOME S0014 (okay for home composting systems); SOIL S0014 (biodegradable); and OK COMPOST INDUSTRIAL S0014 (okay for industrial composting systems).
- European Bioplastics Standard: This standard, EN 13432 is used for compostable materials that disintegrate after 12 weeks and fully biodegrade after six months.
- The Australian Standard Logo: The AS 5810 is one of the few standards indicating home compostability. AS 4736 is also commonly used, meaning suitability in commercial composting facilities.
3. COMPOSTABLE VS BIODEGRADABLE TRASH BAGS: WHICH IS BETTER?
So, which is better: biodegradable or compostable trash bags?
Compostable trash bags are the clear winner.
If you’re wondering where to buy biodegradable trash bags, we’ll provide you with a better option: go for compostable instead. Even the best biodegradable trash bags don’t stand up to compostable options.
According to a recent study, degradable bags and biodegradable bags were still able to carry a load of groceries AFTER THREE YEARS IN THE SOIL.
Compostable bags, on the other hand, were still intact but couldn’t carry weight. However, within three months, they did completely break down in a marine environment.
4. WHERE TO BUY COMPOSTABLE TRASH BAGS
Compostable bags on the whole may be better, but there is still a lot of variance within the market.
Here are some of the best compostable trash bags we could find:
For more than 20 years, BioBag has been a leader in sustainable waste management. They have a range of sizes and their bags are considered suitable for conditions normally found in home composting bins.
BioBag is certified by ISO9001, ISO14001, GMO-free, TUV AUSTRIA (HOME, SOIL, AND INDUSTRIAL), and BPI (compostable in industrial facilities—ASTM D6400), and AS 4736 (compostable in industrial facilities).
They will also disintegrate in a sea environment, but it will require several months (don’t throw your biobags into the ocean).
Zero Waste Club
For anyone worried about three-day-old green juice pulp leaking out of their 13 gallon compostable trash bags, no need to worry with the 100% biodegradable and compostable bags from Zero Waste Club.
The extra strong bags are made from cornstarch certified EN 13432 as okay for home composting.
They also come in biodegradable/recyclable packaging and a tree is planted for every pack sold.
Unni wants to make the world a better place by using plant starch-based bags certified compostable by BPI (ASTM 6400) and TUV AUSTRIA (OK COMPOST HOME).
They make compostable trash bags in 13 gallon sizes, and everything in between (3 gallon to 65 gallon).
Bag to Nature
Bag to Nature has been in the biodegradable bag business since the late 1980s.
Their 100% compostable bags help you “eliminate the YUCK factor.”
Made of a proprietary blend of biodegradable polymers, they’re certified to the ASTM D6400 standard. In an active industrial compost environment, they will be reduced to carbon dioxide, water, and biomass within just a few weeks.
ProGreen’s compostable trash bags (3 gallon to 33 gallon) meet both ASTM D6400 and TUV AUSTRIA (HOME OK) standards.
The bags are also strong and thick, and won’t tear or leak easily!
Second Nature Bags
Also meeting ASTM D6400 and TUV AUSTRIA (HOME OK) standards, the 100% certified compostable bags from Second Nature Bags are suitable for backyard composting and will fully disintegrate in 28 weeks.
They’re made in the USA from bio-based, non-GMO materials including sugar cane, plant starches, and vegetable oils.
They are also clear in color to avoid adding unnecessary dyes.
These 100% compostable bags are made from plants and vegetables (mostly corn starch). Primode bags are easy to use and meet standards for ASTM D6400 and TUV AUSTRIA (HOME OK) standards.
Green Earth only uses GMO-free crops to make their compostable trash bags, which meet ASTM D6400 and TUV AUSTRIA (HOME OK) standards.
These bags run on the smaller end, with 2.6, 3, and 13-gallon sizes available.
Green Earth also donates 1% of its sales to charitable organizations promoting conservation and protecting our planet.
5. ALTERNATIVES TO COMPOSTABLE AND BIODEGRADABLE TRASH BAGS
Bioplastics are a more sustainable alternative for plastic trash bags.
However, it’s important to consider that they still require a lot of inputs. These include fossil-fuel-based fertilizers and pesticides and a significant amount of land to grow the agricultural products.
Their production uses a range of polluting chemicals, too.
While a corn-based PLA is associated with a 25% reduction in greenhouse gas emissions compared to traditional plastic, we can do even better.
By tossing the need for disposable trash bags altogether – the perfect zero waste solution! You can do this by putting your compostable waste directly in the bin or in a bagless compost collector bin.
However, for those who still like the convenience of a trash bag or can liner, the most sustainable trash bag alternative is a reusable one.
Check out the reusable trash bags from the following companies:
We love Etsy for a zillion reasons, including their fully carbon-offset shipping, black owned Etsy shops, zero waste makeup, hand-crafted ethical engagement rings, and unique eco friendly etsy gifts galore.
We can expect the same amazing selection (and opportunity to support small businesses) when it comes to reusable trash bags.
As just one example, Marley’s Monsters (one of our favorite makers of zero waste toilet paper) has a washable pail liner! It’s handmade in Eugene, Oregon with USA-made water-resistant PUL fabric. It also features drawstrings to fit a range of pails.
Bagito isn’t just a product with a catchy name; it’s an innovative one!
This Certified B Corp carries both reusable shopping bags as well as a reusable can liner in three sizes to fit any trash can.
They’re water-resistant and made with an organic microban coating so your trash bag can be machine washed and reused hundreds of times.
Even better, they’re made from 100% post-consumer recycled plastics!
A percentage of proceeds supports Power2Sustain, an organization educating K-12 students on sustainable living.
When you order a trash bag from Planet Wise, you’ll also get something washable, reusable, and, dare we say, cute. They come in 32 different colors and prints.
Who knew trash bags could double as eco friendly home decor?!
The reusable trash bags are made with an antibacterial PUL layer that inhibits fungi and bacteria growth. They are ideal for a five-gallon bin, making them perfect for an office, bathroom, or zero waste kitchen with minimal trash generation.
Another leader in “the smarter way to dispose of waste,” K.A.N Bags are also leak-resistant, durable, machine washable, and can be reused hundreds of times!
Switch to these and you’ll save roughly $150 a year on trash bags!
FINAL THOUGHTS ON COMPOSTABLE AND BIODEGRADABLE TRASH BAGS
Who would have thought taking out the trash would require such a critical examination of all these thin, stretchy green bags?
Unfortunately, the marketing around biodegradable trash bags means that most people *think* they’re saving the planet—when they’re actually inadvertently contributing to microplastic pollution with biodegradable trash bags.
For anyone who wants to ditch trash bags altogether, we don’t blame you.
In fact, that would actually be the best thing for our planet, too. We’d go so far as to recommend saving your money on biodegradable trash bags and instead adopting another zero waste tip of ours.
It might even be easier than you think.
An upcycled paper grocery bag or DIY newspaper bin liner might work just fine—especially if you’re properly composting your food scraps and other organic compostable items and are just left with non-compostables.
If the stink and the mess are too much, compostable trash bags are far superior to biodegradable trash bags. Just be sure you properly compost them, instead of sending them to a landfill with your regular trash.
Please help us dispose of confusing marketing and misleading labels by sharing this with any and all trash-producers (AKA anyone old enough to read).
Together, we can greenify our garbage and, when done right, even support the soil.