In today’s food packaging industry and the larger consumer goods sector, “compostable” materials have become an exciting and confusing new category. As the founder of a compostable packaging company, you might expect me to advocate for a world where every bottle, lid, and utensil is made from compostable materials.
But the truth is more nuanced: in some cases, compostable packaging is a wonderful end-of-life pathway to divert food and other organic waste from the landfill. In other cases, compostable materials can be a terrible choice and can even increase your brand’s carbon footprint. In the rush to meet EPR goals and reduce carbon, many organizations are falling into the trap of material-application mismatch. To build a functional circular economy, we must be honest about where compostable materials shine and, perhaps more importantly, where they have no business being used.
The Gold Standard: Why Food and Compostables are Inseparable
Firstly, a note on plant-based vs compostable packaging. Bio-based ≠ compostable. This is a common misconception, and we must separate the upstream material source (i.e. bio-based vs fossil fuel) from the end-of-life stream (i.e. recyclable vs compostable vs landfill-bound). Plant-based may bring about a slew of carbon wins simply by merit of being renewable, but today we will focus on the compostable end-of-life pathway as it relates to the food industry.
In the waste management hierarchy, food waste is a primary culprit for methane emissions in landfills. When food scraps or other organics are trapped in conventional plastic bags or otherwise anaerobic landfill conditions, they are unable to break down and instead off-gas into the atmosphere. This is where compostable packaging acts as a critical recovery vehicle. Instead of relying on customers to separate their packaging from the food waste inside or to rinse and clean their packaging materials prior to recycling, users can simply send everything to their garden compost or brown/green commercial compost bin.
Second, we must address the unrecyclables: the components that are too small, too thin, or too highly pigmented for most recycling facilities to process. Small-format packaging like condiment sachets, tea bags, caps and closures, or samplers literally fall through the gaps in the sorting process. Similarly, highly pigmented materials (like black plastics) often bypass optical sorters at material recovery facilities. Since these components are bound for landfill or incineration anyway, they are a great candidate to transition to compostable packaging.
Regardless of the feedback, compostable packaging is most valuable in use cases where recycling or reuse is not a viable pathway. In these cases, compostable materials serve as a missing link to a closed-loop or truly circular system.
When Not To Compost
Now the fun part. Compostable packaging is not always the best choice. At Clement Packaging, we receive all types of inquiries. Recently we were asked to make keyboard chassis and keycaps out of our plant-based, compostable material instead of petroleum plastic.
On the surface, it sounds like a win for the planet right? But from a circularity perspective, it is a disaster. Electronics and their accessories should be durable by design. They are energy-intensive products that we want to keep in the economy for as long as possible. Using a material designed to break down in the presence of heat and moisture for a device that sits on a desk for years is a recipe for failure. At least keycaps are replaceable, but if a keyboard chassis starts to degrade prematurely we haven’t created a sustainable product: we’ve created a premature piece of trash. Durables should be made from durable, highly recyclable materials like metals that can be reclaimed at the end of their long lives. We should also avoid using compostable materials in combination with e-waste if they are not easily separable.
We see similar faulty use cases in requests for large-format items. This is now more relevant to our food packaging industry. For example, a bulk gallon jug can technically be molded out of our compostable resin, but that jug may have a lower carbon footprint if it’s made of an infinitely recyclable material. When you make such an item compostable, you are essentially locking up a large volume of carbon in a format that most industrial and home composting facilities aren’t equipped to handle efficiently. Furthermore, a monomaterial PET jug is one of the most easily recycled items in the world. To replace a highly recyclable, high-utility item with a compostable version may not be the most carbon efficient packaging choice.
Sustainability is Not Just Carbon: The Human Safety Mandate
That being said, in the food industry especially we should not solely be focused on carbon footprint when choosing a packaging material. We must also address a growing blind spot in our sustainability conversations: human safety. For too long, “sustainable” has been synonymous with “low carbon footprint” or “renewable.” While those metrics are vital, they are incomplete if they ignore the human toxicity of the packaging material.
Just because something is bio-based or compostable does *not* mean it is safe for humans. In fact, organic feedstocks can be at higher risk for carrying heavy metals and many compostable materials require waterproof lining that can contain PFAS. We certainly do not want these forever chemicals to enter the compost stream, and we don’t want them to contact our ingestible products in the first place.
We should also consider the human safety implications of microplastics. While research is still budding in this area on whether the plastic particles themselves cause harm or if it’s purely the hazardous additives they can bring into the human body, one thing we do know is that microplastics are linked to myriad health issues including endocrine disruption, liver disease, developmental abnormalities, and prostate cancer…the list goes on. This is one area where truly compostable materials can triumph over plastics that simply break down into smaller plastic particles; if it can truly break down into CO2 and water, it will not be leaving behind persistent microplastics that wreak havoc on the environment and our bodies.
True sustainability must be holistic. I urge our industry to choose packaging that is sustainable for both planet and human health.
The Path Forward
There’s no silver bullet in sustainable packaging. We often find that the best packaging solution is a mix of materials, for example an infinitely recyclable glass jar paired with a compostable lid (since the lid is too small to recycle). Compostable packaging is often a great answer to safety and circularity, but it is not always the sensible answer.”
