Trash Talking 101: ‘Biodegradable’ vs. ‘Compostable’ & Other Disposable Terms
- by Maggie Kraft
Not sure which bin to put that “eco-friendly” disposable fork in? It doesn’t matter, because it’s compostable, right? Wrong.
Compostable serviceware is all the rage, and with plastic-straw bans all over the news, biodegradable alternatives are too. But what do those terms actually mean, and which types of to-go ware are the most sustainable? The reality may surprise you.
Knowledge bomb #1: ‘Compostable’ and ‘Biodegradable’ are NOT interchangeable terms
A compostable material is one that breaks down fully (leaving no visible, distinguishable, or toxic residue) in a specific amount of time under certain conditions. The American Society for Testing of Materials sets the standards for what is considered “compostable,” and the products themselves can vary greatly.
The term “biodegradable” has no legal definition. If something is biodegradable, it means it will break down over some period of time — but that time is undefined and not held to a specific standard. The plastics industry often claims their products are biodegradable, which they are if you’re talking centuries. When used by manufacturers, “biodegradable” usually means that in a natural environment (that is, outside a composting facility with high heat and perfectly balanced conditions) a product will break down into smaller and smaller pieces until it can be consumed by microorganisms like bacteria, fungi, and algae. Products labeled as “biodegradable” but not “compostable” do not necessarily meet composting standards and should not be disposed of in a composting system.
The term “biodegradable” has no legal definition. If something is biodegradable, it means it will break down over some period of time — but that time is undefined and not held to a specific standard.
The majority of compostable products are made from a bioplastic called PLA (polylactic acid plastic). PLA is a polymer made from polylactic molecules, usually derived from corn starch. In order for PLA to break down, it requires both high heat and moisture to go through a process known as hydrolyzing. This process is often only possible in industrial composting systems — a PLA cup thrown in your backyard compost or in a landfill will decay as slowly as a traditional plastic cup, remaining intact for decades to come.
The same principles apply to single-use straws: if they’re made of PLA, then they won’t break down unless they’re taken to an industrial composting system. Alternatively, paper straws are biodegradable and will naturally break down regardless of whether they end up in a composting system. Because they’re small and made of paper, they can also usually be composted (at home or through an industrial system). But paper straws aren’t the only biodegradable and compostable option on the market — natural straw-shaped products such as pasta and stalks of grain are also being used as alternatives to plastic straws! (Rye straws were in fact America’s original straws.)
Knowledge bomb #2: Not all industrial composting systems accept bioplastics
If you live in a city that has an industrial composting system, compostable bioplastics may seem like the best option. Except if yours doesn’t accept bioplastics — like the one in Portland, OR, whose methane digester can’t handle them. Any compostable containers in places like Portland can’t be composted or recycled and must be disposed of in the landfill, where they will break down at the same rate as any other plastic.
Knowledge bomb #3: Good ol’ recycling is in trouble
As of January 2018, the U.S. recycling market has been upended because China stopped accepting recycling from the United States (yes, shockingly a high portion of our recyclables are shipped and processed overseas). America doesn’t have the infrastructure to handle the massive volume of its own recycling. This change in policy affects recyclable plates, cups, and to-go containers, but many single-use plastic disposables were never actually recyclable to begin with! For example, plastic utensils and straws have traditionally not been recyclable because of their small size and shape — the machines used to sort our recycling just can’t handle the small products and they literally slip through the system, often ending up in landfills or in our waterways.
I’m so confused. Which to-go ware should I use?
Reusable china, cutlery, and to-go containers are always the most sustainable option, no matter what they’re made of. Even though it takes more energy and resources to create a reusable product, after a certain number of uses (studies show averages ranging from as low as 15 to as high as 50) it is safe to assume the environmental benefits of reusable plates, cups, and silverware would outweigh that of their single-use counterparts. (Check out this website to see the breakeven points for a variety of materials.) For those of you concerned about the impact of washing the containers, rest assured the amount of water and energy used for washing doesn’t come close to the amounts used to produce single-use disposables.
But sometimes you just gotta to-go. Instead of focusing exclusively on how a to-go product ends up, focus instead on the upstream impact of the materials and processes that went into making the fork, cup, or clamshell in the first place. The best rule of thumb is to prioritize products that are made of a material that comes from a renewable feedstock like recycled paper, bamboo, or corn. The harvest and production of nonrenewable, petroleum-based feedstocks such as virgin plastic and Styrofoam contribute to climate change, while harvest and production of renewable feedstocks typically have less of an environmental impact.
Yes, this topic is as messy as a mile-wide landfill. But don’t give up. Do your best to avoid single-use plastics by carrying your own refillable bottle or coffee mug, even a cutlery set. And if you find yourself standing in front of a coffee shop’s trash can holding your compostable coffee lid in confusion, give that feedback to the establishment. Properly labeled bins with pictures of the specific items help keep these complicated systems running efficiently.
Maggie Kraft was formerly a Bon Appétit Fellow before becoming a waste specialist for the company.