It has a plastic appearance, a plastic feel, and a plastic capacity to hold your favorite beverage. However, there is a label on the cup you were given that says “100% biodegradable.” Is that even possible?
Simply defined, this plastic-like substance is polylactic acid (PLA), a polymer made up of many small lactic acid molecules produced from the fermentation of starch plants such as corn, cassava, or potato plants.
In recent years, single-use cups and take-out containers made of PLA, also known as bioplastic or biopolymer, have grown increasingly popular, with the belief that a biodegradable container is better for the environment than a regular plastic container.
In reality, it depends on your location and who you ask.
Under the appropriate conditions, compostable polymers such as PLA compost.
But, contrary to popular belief, just because something composts doesn’t mean it’s inherently “green.”
It takes more than a backyard container to compost PLA.
Sego Jackson, a waste management strategy adviser and policy liaison for Seattle, Washington, one of the few cities in the US that compels companies to utilize recyclable or compostable items, argues that not all labels are equal in the greenwashed world of food service products.
You could come across a transparent cup with the word “biodegradable” written on it, or labels that state “produced from plants” or “plant-based.”
But, as Jackson points out, this does not imply that your cup is biodegradable or composed of anything different than ordinary plastic.
He adds that these ambiguous phrases might refer to a variety of things, but most commonly relates to the fact that some plant-produced starch was added with ordinary plastic.
Although this form of plastic is less long-lasting and breaks down into smaller pieces more rapidly, little plastic particles are still plastic and will remain in the environment.
If a cup or container is labeled biodegradable, it is most likely compostable under extremely precise circumstances.
The Biodegradable Goods Institute (BPI), a non-profit organization that conducts independent tests of compostable products to ensure that they decompose, has tested and approved the majority of biodegradable PLA products on the market.
BPI certification is necessary by law in Washington state before a single-use product may be called biodegradable at all.
Even still, these highly precise composting conditions are difficult to find.
According to Nora Goldstein, executive editor of BioCycle magazine, which covers the organic waste recycling and composting business, tossing a PLA cup into your home compost pile won’t break it down.
She explains, “I put [compostable plastic] cups from NatureWorks in [my home compost] from early fall last year, and they’re still there.”
She claims that the only way to get the cups to break down is to employ a special type of bacteria used in commercial composting, which requires temperatures far higher than those found in most garden piles to flourish.
According to Craig Coker, owner of Coker Composting and Consulting in Troutville, Virginia, and a senior editor at BioCycle, the cups and containers have been tested in the lab and at composting facilities to ensure they break down within an approved timeline, usually, six months, to comply with the ASTM International standard.
Composting isn’t a panacea.
While composting PLA goods is undoubtedly healthier for the environment than throwing them away, the current composting method has several flaws.
To begin with, there are very few PLA-processing plants in the United States.
In a countrywide study of composting facilities, BioCycle discovered that just 49 out of 4,700 composters accepted biodegradable plastic goods.
Even if the intentions are noble, giving biodegradable cups to a restaurant or venue means nothing if the local trash infrastructure isn’t geared up to handle them.
Composters are unwilling to modify their practices for a variety of reasons.
According to Coker and another BioCycle study, the first and most common difficulty is that PLA and conventional plastics are difficult to distinguish.
People frequently mistake the two, which is understandable given the uncertainty of the labeling process.
As a result, if a compost maker decides to accept PLA cups, ordinary plastic contamination may readily enter the compost stream, according to Jackson.
Regular plastic, on the other hand, will not decompose, no matter how hot the compost pile is.
According to Coker, this plastic contamination can diminish compost value and lead to plastic pollution in the soil and rivers.
Furthermore, according to Coker, some industrial composters run on a quicker cycle than is necessary for breaking down PLA and aren’t encouraged to adjust.
In the United States, compost generated with PLA containers cannot be certified organic.
This may be a major issue for composters who rely on organic producers for the majority of their income, according to Coker.
According to Rafael Auras, an associate professor at Michigan State University’s School of Packaging, “since there are so few facilities willing and able to handle PLA, a lot of material ends up in the trash.”
PLA that has been dumped on the ground does not always disintegrate any quicker or better than ordinary plastic, which might take hundreds of years to break down into microscopic fragments that never truly disappear.
And, if PLA is exposed to hot enough landfill conditions, the microorganism-rich but oxygen-depleted atmosphere might lead these “green” cups to produce methane, which contributes to greenhouse gas emissions.
While this carbon impact may appear insignificant in comparison to our food system’s massive methane problem, landfills remain a less-than-ideal burial site for biodegradable PLA, according to a 2012 research by NatureWorks LLC.
According to Auras, PLA might also wind up in the regular plastics recycling process by accident.
Compostable plastics can create contamination there, forcing costly sorting interventions for facilities that are currently equipped.
According to BioCycle’s Goldstein, “the distribution of these goods, as well as their usage and sales, outpaces the current infrastructure.”
PLAs raise several issues, even when composted.
Even after a biodegradable cup reaches the appropriate facility and is cycled into the soil, there is still dispute regarding the product’s overall environmental effect.
A study of life cycle assessments (LCAs) of several types of compostable single-use foodware was released by the Oregon Department of Environmental Quality (DEQ) in 2019.
When considering compostable alternatives’ reliance on an already troubled agricultural system, their findings showed that conventional plastics were better for the environment than compostable alternatives.
Monoculture maize, the primary source of PLA in North America, has several well-known environmental drawbacks.
However, not everyone agrees with the Oregon DEQ’s findings.
Many of the studies evaluated, according to BPI, were older than five years, a significant time gap for rapidly evolving compostable manufacturing technology.
According to Rhodes Yepsen, executive director of the BPI, the assessment primarily ignored the detrimental effects of the fossil fuels used to make traditional petroleum-based plastics.
Another benefit of biodegradable foodware that is often overlooked is its potential to divert food waste from landfills—leftover food may simply be thrown into a green bin with its container.
Food waste is the third-largest source of human-caused methane emissions in the United States, yet discarded leftovers create far less methane in the compost than if they were landfilled.
Oregon has stood by its report, and a group of composters in the state has refused to accept PLAs.
However, in terms of greenhouse gas emissions and overall climate change consequences, some studies have placed PLAs ahead of single-use standard plastics.
So yet, there is no clear answer as to what the PLA’s true influence on the world is.
What must be done to make foodware genuinely environmentally friendly?
Rejoice if you get a biodegradable cup in Seattle or San Francisco! If you put it in the right bin, it will be composted and utilized to grow future crops.
However, if you’re in another part of the nation, it’s reasonable to be dubious.
Some big venues, such as stadiums, have created their composting systems and are likely to have waste management agreements in place.
Your home compost heap, on the other hand, probably doesn’t, and neither does your local café.
The discussion over single-use compostables vs. recyclables may continue, but according to Jackson, reusable goods are nearly always healthier for the environment than either.
Although biodegradable cups can be handy in a pinch, he believes that a cup that isn’t thrown away at all is a superior choice.