More disposable food service ware (FSW) products and packaging makers describe their products as “eco-friendly” or call them biodegradable, compostable, bio-based, or bioplastic, which might make you think they can all be composted. Let’s look at what these terms mean, how they compare to the alternatives, and how to identify compostable material that will not have adverse environmental impacts.
Wishful composting is a growing problem because it can lead to contaminated soil at home or disrupt industrial composting operations, among other problems. Composting guidance available to citizens and businesses may be confusing or incomplete, but there are steps you can take to reduce contamination of your compost pile with uncompostable stuff, or worse, sending such products for recycling or to a landfill.
Adopting truly compostable packaging and FSW products represents an important path to a circular economy and could reduce waste from disposable plastics. In the meantime, it’s up to us to make responsible choices.
Some Definitions to Get Started
The Sustainable Packaging Coalition’s (SPC) guide to compostable packaging describes what can be composted:
… materials [that] are degradable by biological processes to yield carbon dioxide, water, inorganic compounds, and biomass at a rate consistent with biodegradation of natural waste while leaving no visually distinguishable remnants or unacceptable levels of toxic residues.”
However, the guide also adds an important caveat: “biodegradable is a general concept that refers to materials breaking down over unspecified amounts of time, and usually in unspecified environments.”
Generally speaking, there are two types of compostable packaging: fiber packaging and compostable bioplastic packaging.
- Fiber packaging is made from plant fiber such as sugarcane, wheat straw, and bamboo, and is used for a variety of FSW items.
- Bioplastic packaging (sometimes called bio-based plastic packaging) is derived wholly or partly from renewable biomass sources such as sugarcane and corn, or microbes such as yeast. PLA (poly-lactic acid) is a common example that you may see on product labels.
Some bioplastics are biodegradable or compostable under the right conditions, but many are not. For example, Bio PET products, such as the PlantBottle from Coca-Cola cannot be composted. Even though up to 30% of the Bio PET plastic is plant-based, it is chemically the same as a conventional PET bottle and must be recycled. On the other hand, some compostable plastics are derived from petroleum, such as Ecoflex from BASF.
The industry-supported SPF suggests that compostable packaging’s primary value is that it can be used in foodservice settings “to capture food waste and deliver it to the composting bin.” Supposedly, consumers don’t need to sort, wash, or separate this packaging from food scraps. However, the process is far more complex in the real world.
Not All Composting Methods Are Equal
There are several different types of composting. Home composting can handle plant-based food waste, paper, and yard trimmings. Most of the compostable packaging or food service ware items need a larger industrial or commercial composting facility. Not all cities offer commercial composting, and of those that do, most accept only yard and food waste.
The proper way to dispose of these products is to take them to an appropriate industrial compost facility that accepts such products. But there are challenges, including:
- In the U.S., only about 15% of composting facilities accept some form of compostable packaging. Most of these are concentrated in the largest urban areas.
- In Canada, only 10 of 97 composting facilities accept fiber compostable packaging; only one accepts all composting products, including bioplastics.
Just as putting the wrong materials in your recycling bin contaminates local recycling systems, sending compostable packaging or FSW items to a composting facility not equipped to handle that material contaminates the commercial composting system.
Compostable Products: “Your Mileage May Vary”
Products labeled as compostable don’t always fully break down within the normal composting time frame. This happens because certification standards test compostability based on laboratory conditions, which may not replicate real-world composting facilities. If it takes longer to break down, the composter needs to separate and manage these items, increasing their costs.
Another problem is that compost created from bioplastics cannot be sold to organic farmers because of residual materials left in the compost.
Contamination from lookalike packaging is another significant problem. It can be hard to tell compostable items apart from non-compostable ones. Many paper/cardboard-based boxes and cups have a polyethylene inner lining that does not break down in a compost pile.
For such reasons, many composters do not accept (or have stopped accepting) compostable packaging and food service ware. For example, the association of Composters Serving Oregon has published its reasons for not accepting these anymore. Similarly, in a March 2021 article titled, “Wishful Composting Cannot Follow Wishful Recycling,” the California Compost Coalition wrote that it has banned many FSW and packaging items.
Environmental and Health Impacts
One benefit of bio-based plastics touted by their makers is that they are derived from plants and not from fossil fuels. So even if we send them to landfills, that’s more environmentally friendly than using conventional plastic plates and cups (which are hard to recycle), right? Not necessarily.
Because compostable packaging may contain toxic chemicals, we need to be careful to separate materials. In January 2018, the nonprofit Center for Environmental Health (CEH) released a report on per- and polyfluoroalkyl substances (PFAS) in disposable food service ware. PFAS, also called forever chemicals, build up in our bodies and have been linked to cancer, reproductive harm, endocrine disruption, and other diseases. Water- and grease-resistant products “consistently tested as fluorinated,” including those made of supposedly organic materials such as wheat fiber, plant fibers, and “recycled paper and PLA-lined molded sugarcane (bagasse).” Another 2020 study published on ScienceDirect covered 43 everyday bio-based or biodegradable products and found that overall “comparison with conventional plastics indicates that bioplastics and plant-based materials are similarly toxic.”
Keeping fossil fuels in the ground is a desirable objective. However, compostable packaging and FSW introduce a broader set of trade-offs, including choosing between the raw materials used to make several types of compostable packaging and the environmental impacts of producing them. These include pollutants released during the production of bioplastics, or the fact that the land or crops required to produce bioplastics may compete with food production.
Bio-based packaging may produce more methane emissions than conventional plastic packaging when decomposing in a landfill. Landfills lack oxygen, so decomposition is carried out by anaerobic bacteria that release more methane than CO2. Methane is 25 times more powerful than carbon dioxide when it comes to trapping heat in the atmosphere.
Instead of making responsible decisions easy, compostable products present complex environmental consequences. In part 2 of this two-part series, we will take a closer look at several industry initiatives that can help you identify safe biodegradable options for food packaging and service ware.
About the Author
Renga Subramanyam is a sustainability professional who favors a balanced, whole system approach to environmental sustainability. He has obtained his ISSP-SEA certification from the International Society of Sustainability Professionals. In collaboration with A Plastic Planet, he focuses on addressing the plastics pollution crisis to help businesses in the U.S. work towards alternatives to single-use plastics and to increase awareness of the limitations of plastics recycling