In this special guest feature written by staff member, McKenzie Dunlap, learn more about these plastics touted as the greener alternative.

Ensuring Circularity with PLA

If you’re a consumer who is interested in a greener alternative to petroleum based products, PLA could be a good option for you. In recent years, PLA serviceware has hit the market as a greener alternative to serviceware made from petroleum-based plastics. However, many consumers aren’t aware of the special processing that is needed for it to live up to its greener reputation and to truly tap into its full potential for circularity.

The benefits of PLA are negated if it just winds up in a landfill. Waste disposal infrastructure needs to pivot and develop in new ways in order to support the growing demand for more environmentally responsible plastics. If ethical consumption is exercised and PLA is disposed of properly, it could live up to its green reputation. Otherwise, it’s missing a crucial piece of the sustainability puzzle.

What is PLA?

PLA is a type of #7 plastic made from plant starch that is biobased, biodegradable, AND compostable. The PLA stands for Polylactic Acid and can be found just under the Resin Identification Code number inside of the triangle or chasing arrows symbol.

It is important to note that not all #7 plastics are PLA, and #7 plastics that are not labeled as PLA are not compostable. Examples of #7 plastics that are NOT compostable include ABS, PC, and #7s marked OTHER.

Additionally, some plastics are labeled as ‘biodegradable’, but this can be misleading. Biodegradable items do not necessarily meet the more stringent guidelines laid out for compostable ones. A good way to conceptualize this is to remember: while all compostable items are biodegradable, not all biodegradable items are compostable.

How should you dispose of PLA?

With PLA, proper disposal is key! If it is placed in the garbage and ends up in the landfill, it will behave much like petroleum-based plastics, sitting for hundreds of years. PLA needs to be industrially composted. Many communities do not have access to the necessary facilities, so for them, unfortunately, purchasing PLAs is of no real benefit.

However, Cincinnati Recycling & Reuse Hub is partnering with GoZERO to help eliminate that barrier to access and to ensure that PLA serviceware makes it to an industrial composting facility to break down properly. GoZERO is a nonprofit organization based out of Zanesville, Ohio that offers composting services, picking up material from collection sites and transporting it to nearby industrial composting facilities to be processed.

It’s important to note that industrial composting and home composting are not the same.

Industrial composting facilities are specially equipped to provide the conditions (high temperatures, adequate moisture and aeration) that PLA needs to break down into a proper soil-conditioning material. Under these conditions, not only will the PLA break down, it will break down into components that have no ecotoxicity and are BENEFICIAL for the soil.

CERTIFICATIONS/HESITANCY OF INDUSTRIAL COMPOSTERS

Despite PLA being designed to break down under industrial composting conditions, many industrial composters are hesitant to accept it. This is largely due to the risk of contamination with petroleum-based plastics. For example, at a glance, PLA cups are indistinguishable from regular plastic cups. If a composter opens up their stream to PLA, they will need to be confident that the cups they are seeing in their incoming material are PLA or will need to establish an additional layer of processing for quality control.

#7 PLA cup on the left, #1 PETE cup on the right

In addition, industrial composters want to be confident that the PLA will break down within a certain time frame, a maximum of 180 days. This is where certification comes in. Internationally, the ASTM D6400 sets the standard for compostable plastics. The Biodegradable Products Institute (BPI) is a North American third-party verification program that confirms that specific products have undergone rigorous testing to ensure that they will compost in industrial conditions. BPI has a searchable database that contains listings for every product that they have certified. This can be a useful tool, since not all BPI certified items are individually labeled as such.

While many PLA items are BPI certified, there are some outliers. Certain brands of PLA, like World Centric®, fall outside of the BPI certified umbrella, but have been tested and verified for compostability through other processes.

It’s also important to note that some regions outside of North America have their own standards for compostable plastics. For example, Austria uses the ‘OK compost HOME/INDUSTRIAL’ labels, and the ‘seedling’ logo is used throughout Europe.

These standards and certifications give industrial composting facilities assurance that the materials they are taking in can be processed properly and will not compromise the quality of their end product, serving the same role as BPI certification.

WHAT ABOUT PLA FILAMENT AND SCRAPS FROM 3D PRINTERS?

Often, 3D printers use PLA filament. However, this material is generally not accepted in industrial composting facilities. This is because the filament/printing scraps are not labeled as PLA, so it is very difficult to verify the material type. Also, some PLA filament could have additives that render it non-compostable. However, that doesn’t mean that your 3D printing PLA needs to be landfilled!

There are a few options available:

Printerior offers recycling services specifically for 3D prints and filament, turning the material back into filament to be used again.
TerraCycle also offers a recycling option for recycling 3D printing materials.

COMPOSTING PLA WITH THE HUB!

If you do opt for PLA serviceware, remember to bring it to the Hub to be composted through our partnership with GoZERO! PLA items can be placed in the #7 bin on the rigid plastics shelf in the Mini Hub and will be separated out from the non-compostable #7s by staff or volunteers. This ensures that materials are sorted into the proper waste streams and can be processed accordingly.

Happy composting!

PLAy by the rules: Learn how to properly dispose of these materials so they fulfill their greener promises