Why compostables and bioplastics aren’t the answer
Bioplastics and compostable packaging are often presented as green substitutes to single-use plastic.
But are they really better for the environment?
We know that brown paper take-out box and the bioplastic fork seem better for the environment. After all, it says “compostable” on them. But unfortunately, when we substitute one single-use product for another, we’re often out of the frying pan and into the fire. There are big commercial interests trying to harness the public’s outrage over single-use plastics and push it to single-use something else – mostly compostable packaging or bioplastics. Products like paper to-go boxes and bioplastic cutlery often require more energy, water and toxic chemicals to produce than single-use plastics. What’s more, they usually don’t effectively compost, and many composters don’t want them because they degrade the value of the compost. The real problem isn’t just single-use plastic, it’s “single-use” itself.
Definitions: biodegradable vs. compostable
“Biodegradable”
Means 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.
“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.
Across numerous measures, compostable and bioplastic foodware have greater environmental impacts than the alternatives.
Compostable food service ware can be made of bio-plastic, paper, and plant-based fibers. The environmental impacts from producing, using and disposing of compostable products typically outweigh the advantages. Across numerous environmental impact measures, compostable food service ware has greater environmental impact than the alternatives, like:
higher global warming impacts
more land and resource exploitation,
greater ecological and human toxicity and aquatic impacts.
It doesn’t matter whether the compostable product was composted, landfilled, or incinerated. Composted foodware that is composted – compared to non-compostable foodware that is landfilled, incinerated or recycled – is generally not preferable.
Compostable products and bioplastics often produce more greenhouse gas emissions (GHGs) than single-use plastic due to emissions released during the agricultural phase.
Growing crops to make materials consumes significant amounts of fossil fuels.
Additionally, compostable fiber-based (paper) packaging products that end up in landfills release methane, a GHG that traps more heat than carbon dioxide by thirty-fold.
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 increase acid rain, contaminate soil and water resources with fertilizers and pesticides, and cause overloads of nutrients in waterways (“dead zones”).
The water used in the growing phase of bio-based plastics make them a less favorable choice among single-use foodware options, whereas the consumption phase (i.e. warewashing) for reusables represents 85-95% of the water impacts of reusable foodware.
Over their life cycle, reusable products, foodware and packaging use less water than using disposable alternatives.
Compost facilities don’t want bioplastics, and many don’t accept compostable foodware because of the contamination they cause.
Compostable food packaging does not consistently function as intended in many compost facilities and can cause contamination in the final compost product.
Unlike food waste and yard trimmings, compostable packaging and bioplastics do not add valuable nutrients to compost.
Because of this, most commercial composting operations don’t accept compostable bio-plastics and many are no longer accepting any compostable packaging – plastic, paper or otherwise.
In a study that surveyed 148 curbside collection programs, less than half accepted compostable bioplastic products, such as bags and food containers; less than a quarter accepted paper containers; and only 7% took coated paper.
Composters serving Oregon ask their residents not to place plastic compostable foodware in the compost and to use reusables to save money and decrease the amount of items in the waste stream. Many commercial compost facilities in California do not accept bioplastic, and some don’t accept any foodware at all.
There is no evidence that composting “compostable foodware” provides any benefit compared to treating it through recycling, landfill, or incineration.
When compostable products end up in a landfill or incinerator, the greenhouse gas footprint of the material increases.
Many products that claim to be compostable or recyclable aren’t passing the reality test. They may not be collected at all for recycling or compost, or they may be collected but then get diverted to landfill or incineration. And even if they do pass the reality test, the life cycle assessments on balance show that these products only sometimes deliver real sustainability benefits.
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?
