Why compostables and bioplastics aren’t the answer
Bioplastics and compostable packaging are often presented as green substitutes to single-use plastic. Consumers and businesses buy into the narrative because they want to do the right thing.
But unfortunately, compostables and bioplastics do not tend to be any better for the environment and are most often simply a regrettable substitution.
The brown fiber take-out box and the bioplastic fork seem better for the environment than single-use plastic — after all, they say “compostable” — but in reality they are trading off environmental harms. Products like paper to-go boxes and bioplastic cutlery require more energy, water, and toxic chemicals to produce than even single-use plastics. What’s more, organic materials in landfills produce methane, a powerful greenhouse gas, so without commercial composting facilities, the end of life for these products is bad news for the climate.
The real problem isn’t just single-use plastic, it’s single-use itself.
Definitions: biodegradable vs. compostable
“Biodegradable”
Materials that can ultimately decompose with the help of bacteria and fungi and turn into water, carbon dioxide, and biomass as a result. Biodegradation is a process that occurs without human interference and within no specific time frame. Compostables, and especially bioplastics, that end up in the environment may or may not biodegrade.
“Compostable”
Composting, on the other hand, is “human-controlled degradation.” Items that are compostable are also biodegradable, but they break down in a much shorter time frame determined by the composting facility – usually around 80 days. One purpose of composting is to produce nutrient-rich soil for agricultural production.
Debunking the compostable food serviceware myth
Compostable food serviceware can be made of bio-plastic, paper, and plant-based fibers. Many bioplastic compostable products are made from PLA, which is usually derived from corn. Most compostable plastic cold cups and cutlery are made from PLA.
Compostable food serviceware has a heavier environmental toll than the alternatives across numerous measures – global warming impact, land occupation, eco- and human toxicity, and aquatic impacts. It doesn’t matter whether the compostable product is composted, landfilled, or incinerated. This is typically because most food serviceware marketed as compostable is produced with agriculturally derived feedstock (sugarcane, corn, potatoes, etc.) that require extensive use of fossil fuels related to pesticides, fertilizers, and farming equipment. The final act of composting the package does not offset the impacts of the fossil fuel inputs. Compostable food serviceware (if composted) typically results in higher environmental impacts when compared to other food serviceware that is non-compostable, even if that other food serviceware is landfilled.
Greenhouse Gas Emissions (GHGs) are higher.
Compostable products often produce more GHGs than alternative single-use products due to emissions released during the agricultural phase. Growing crops to make materials consumes significant amounts of fossil fuels. Additionally, compostable packaging products that end up in landfills release methane, a GHG that traps more heat than carbon dioxide by thirty-fold.
Ecotoxicity is a concern.
Growing crops for biomaterials can increase acid rain, contaminate soil and water resources with fertilizers and pesticides, and cause nutrient overloads (dead zones) in waterways. While bio-based and compostable materials are constructed from renewable resources, such as corn and potato starch, growing these materials can cause air and water quality impacts. The water consumption in the growing phase of bio-based plastics also makes them a less favorable choice among single-use food serviceware options.
Many compostables that look and feel like natural fibers molded together are made with toxic chemicals like PFAS to make them waterproof. These “forever” chemicals are linked to harmful health impacts in adults and children, and communities are finding PFAS in their compost piles from compostable food ware that was mixed in.
Many compost facilities don’t want compostable plastics, and many don’t accept any compostable food serviceware, because of the contamination it causes.
Contamination is a huge problem for composting facilities, and much of the equipment they buy is specifically designed for removing contaminants. When compostable packaging is accepted, non-compostable “look-alike” plastic packaging also enters the compost stream. Moreover, much compostable food serviceware does not function as intended in many compost facilities because currently marketed products, particularly compostable bioplastic, does not degrade within the 60-90 days required by commercial composters, even when certified as meeting current ASTM standards. Unfortunately, the sorting equipment (and the removal of the contaminants) also causes problems, often pulling good organic matter along with the contaminants, which then gets sent to landfills, where it produces climate-warming methane.
Further, while compostable plastics are not the biggest contamination source in the compost stream, many composting companies want their soil product to be certified as organic because it’s a better, more profitable product. However, they cannot receive Organic Certification if they process bioplastics, because the highly processed packaging is considered synthetic.
Fiber-based compostable packaging is practicably compostable in commercial compost facilities and is not considered a contaminant. However, unlike food waste and yard trimmings, fiber-based compostable packaging does not add valuable nutrients to compost and is recommended to only be a small mix of the total makeup of commercial compost.
The bottom line.
Reusable foodware is always the best choice if you are looking for a better alternative to single-use plastic. Understandably, it seems much easier to switch from one kind of single-use to another, rather than redesigning your whole system to accommodate dishwashing. Though reusable options may not be possible in every use case, it’s important that if you choose to go compostable, you do so fully informed. We recommend turning to BPI (the third-party certification organization for compostable products) for the most practicable option for your given situation.
Resource Library
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Why Oregon Composters Don't Want "Compostable" Packaging
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Oregon Department of Environmental Quality Report
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Compostable food containers could release PFAS into environment
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Bioplastics: sustainable solution or distraction from the plastic waste crisis?