Ask Pablo: Does This Compostable Plate Have to Go in the Compost? Can I Recycle It?

Burger and chickpea side dish on a compostable plate

Albert Hu / Unsplash

Dear Pablo: Our café uses dishes by Ecoproducts. Each plate has "Compostable" and "Tree Free" embossed on the surface. Does this plate need to go into a compost? Or can it be thrown into a recycling bin? What happens if it ends up in a landfill?.

Over the years many of us have become conditioned to divert resources from the landfill by recycling. This not only keeps landfills from overflowing but it also displaces some of the need for virgin materials from non-renewable resources (petroleum, old-growth forests, etc.). But with our new eco-conscious society in mind, manufacturers are producing more and more products that are seen as more "green." Among these are compostable bio-plastics and tree-free products. Our eco-urges want us to place them in the recycle bin along with normal plastic and paper but now we have the "compostable" label to worry about.

What Does Compostable Even Mean?

In the industry the word "compostable" is defined by ASTM 6400 ("Standard Specification for Compostable Plastics") and ASTM 6868 ("Standard Specification for Biodegradable Plastics Used as Coatings on Paper and Other Compostable Substrates") as 90% biodegradation within 45-120 days with no remaining toxic residues. If a product is certified as compostable by the Biodegradable Products Institute it meets these requirements.

Can I Still Recycle Compostables?

PLA (biodegradable bio-plastic made from GMO corn) can now be found in everything from water bottles to cutlery. While it can technically be recycled, as Plus1 claims, it can also be seen as a contaminant in the PET recycling stream which compromises the revenue of recycling plants. In addition to this people are still uncomfortable with throwing a bio-plastic into the compost bin because it seems to go against everything that we were taught. This means that a great share of the biodegradable plastic is neither composted, nor recycled. The landfill is often the safest bet for the conflicted.

Your tree-free plates are most likely made from bagasse, the fibers of the sugarcane plant. About 5-10% of the world's paper production uses agricultural fibers, which includes bagasse. Bagasse is well-suited for making paper because it requires less bleaching to make bright white paper. Unfortunately, when used for food, there is a lot of potential for contamination and the recycling plant may just divert it to the landfill anyway. Pizza boxes, for example, are often so contaminated with grease or cheese that many recyclers don't accept them. So, while bagasse is an excellent material for making paper, it will most likely end up in the landfill if it has been used in food service.

So, if It Ends up in the Landfill, What Happens to It?

When we throw things "away" to a landfill they don't really go anywhere. When there is enough moisture and the right microbes present, some of the waste is turned into methane gas which either leaks into the atmosphere or is captured and flared. Methane is a potent greenhouse gas (23 times more potent than carbon dioxide) and best landfill management practice says that landfills should be kept dry to avoid its creation. But even if your cups and plates sit there for thousands of years, it could be worse.

The end-of-life impact of your choice in cups and plates is only part of the equation. The bigger part is the resource extraction and manufacturing part. Even if a package made from renewable materials ends up in the landfill, it can still have less of an impact than a fossil or mineral-based material that is recycled (See:Which Milk Container Has The Lowest Carbon Emissions?). By selecting a product that is made from renewable sources rather than non-renewable sources, you have already made a good decision. When it comes to potentially contaminated food ware, composting is the most environmentally friendly thing to do. But even if composting is not an option, it is still a better choice than food ware made from non-renewable materials.