A lot of attention has been given to the China Recycling Ban. But there has been less attention given to the immense challenges facing the composting industry, which has been taxed by the ever increasing interest in biodegradable plastics and other materials.
In the last few years, more and more people are turning to compostable single-use packaging, including bioplastic. There is a lot of myth and silver bullet thinking around compostable materials. Many people believe compostable goods always biodegrade “into nothing” - no matter where they end up. Most consumers are also not aware that composting is just as much of an economic cycle as recycling is, and in many ways, is fraught with more challenges.
We recently had the chance to talk with a local waste management company and got an inside view into the obstacles composters face, how varied the challenges are between composters, and how the industry is evolving to meet the rapidly expanding demand from communities to have the ability to compost.
Here we share 8 things to know about composting and 6 ways to run a compost-friendly house and business.
1. Your compost waste goes through a complex supply chain
If you are lucky enough to have an industrial compost service, it gets picked up by your hauler and then dropped off at a composting facility. The composting facility tries to remove the contamination (a process that is a mix of manual and automated). Different composters use different methods - some are anaerobic (oxygen-free), some are aerobic windrows (where the compost is turned and mixed), and some are aerobic static.
After 120 days, the compost is sifted, so anything that hasn’t biodegraded fully is filtered out. Then, the composter has to sell their product! Currently, most are selling their compost to be used in landscaping and construction. Other potential markets could include farms and public lands.
2. The economics are very hard, across the entire chain.
From a hauler’s perspective, it often costs 1.5-2x more to haul to the composter per lb than to the local landfill. As a result, households and businesses are often charged more for compost than landfilling. From the composter’s perspective, composting is a relatively expensive operation to run, and currently, most composters don’t have ready access to many local, eager buyers for their output. Because of this, some environmental organizations are working to encourage more landowners and farmers to utilize compost for soil amendment. For this strategy to be successful, compost has to be high quality and relatively uncontaminated.
3. Composters are struggling with the recent increased interest in compostable wares.
Most composters started years ago in response to an industrial need. For example, our local composter was originally developed to work with Coors Brewing Company, as a way to sustainably compost their main organic waste stream - spent grains. The aerobic, windrows compost system they developed is a good match for this type of homogenous waste. Over time, they began to accept yard waste. Then food waste. Now they accept compostable wares such as PLA cups and cutlery and paper, PLA lined to-go cups. Most composters have a similar story of step by step expansion in what they are willing to accept. In fact, the majority of US composters still don’t accept anything beyond yard waste and food. Those that do have reluctantly diversified what they accept in response to municipal pressure, and most aren’t currently equipped to fully deal with their change in inputs.
4. 120 days is an important distinction!
When the terms are used correctly (which they often are not!):
Biodegradable means that something CAN completely break down and decomposes into natural elements. It does not say anything about the conditions under which the material would biodegrade or how long it takes to biodegrade. Note that biodegradable is different than oxobiodegradable or photodegradable, which typically mean that a material degrades, but degrades into tinier synthetic elements (i.e. microplastics).
Compostable means that something will biodegrade under at least some type of compost conditions.
Items labeled as certified industrially compostable means they have passed a certification (likely BPI). These items often require the controlled temperature and pressure environment of a composting facility to biodegrade, so they often do not biodegrade in a home compost environment. They also need to biodegrade fully within 120 days. After 120 days, the compost facility will sift the pile and remove anything that hasn’t composted fully.
Items labeled as home compostable don’t need such strict temperature and pressure conditions to compost. However, they may also need more than 120 days to compost.
PAPER is an example of a material that is naturally biodegradable, home compostable and industrially compostable.
HEMP TWINE is an example of a material that is naturally biodegradable, home compostable but is NOT industrially compostable (because it takes more than 120 days to compost).
PLA (a corn-based bioplastic) is an example of a material that is typically certified as industrially compostable, but is not naturally biodegradable (it would not degrade in a non-compost environment such as the landfill or as litter), nor is it home compostable.
Phew! It is not surprising that these designations are so confusing! And unfortunately, we’re about to throw another wrench in this.
5. Even with certification processes like BPI, it is difficult to know how some materials will behave in an actual compost.
The BPI compostable certification process is an excellent resource because it recognizes that “biodegradable” as a term is not helpful! However, composters often struggle to process even certified compostable wares. For example, our local composter uses a windrows composting system. The heat in the center is well managed, but the edges of the compost tend to stay at a lower temp. When the compost is mixed to get everything into the high heat center of the compost, compostable plastic bags tend to rise to the top and can blow away. On the other hand, Portland Oregon has an anaerobic composting system, whose heat can sometimes be very high, and if it is too high, it can inhibit the microbes that digest compostable bioplastic. This means that while BPI certification is helpful, field testing is actually very important.
6. Contamination abounds...and can be harder to deal with than in recycling
Composters can’t always distinguish between compostable plastic and non-compostable plastic. They also deal with things like plastic stickers and adhesives (i.e. the label on a banana peel) which sometimes biodegrades and sometimes doesn’t. After 120 days, the facility will sift out items that haven’t biodegraded. But often, there may be small flecks of undegraded material - including things like cotton (naturally biodegradable but would not have biodegraded within 120 days), traditional plastic, oxobiodegradable palstic, and even compostable plastic that hasn’t fully biodegraded yet. Separating these flecks from compost is extremely challenging and imperfect, lowering the quality of the final product and making it less valuable to end markets.
7. The above challenges have caused Portland to stop accepting compostable wares...and other composters may follow suit
Portland Oregon households are now told to landfill their compostable wares, and to only compost yard trimmings and food waste. This is a bold and somewhat shocking decision that reflects the struggle composters face balancing the desires of their communities with the realities of their business. Here's a great summary from The City of Portland's website: https://www.portlandoregon.gov/sustainabilityatwork/article/468043.
8. Compostable wares are most valuable in food and food service
Today, most composters, as well as the Compost Council seem to agree that compostable wares have an important role in food packaging and food service. In these situations, composting the packaging means that food waste and residue end up at the compost facility and not in the landfill. Compostable wares are particularly well suited to a “closed” event like a concert venue, where a lot of food waste is expected and the venue can better control signage and bins for waste, so the chance that items end up in the right waste bins is much higher. Outside of food packaging, composters don’t really want to see compostable wares.
Clearly composting is a confusing and evolving industry! What does this mean for you as a household and as a business when it comes to compostable packaging.
1. Become familiar with what your composter will and will not accept. Some take yard waste. Some take food. Some take wax paper. Some take compostable bioplastic. Some take none of these!
2. When in doubt, throw it out! Confused by the end of life instructions on a package? Not sure if that paper is lined with wax or plastic? If you’re not sure, throw it out! Having an item end up in the landfill is a better outcome than contaminating the composting waste stream.
3. In designing your own packaging, if you are not packaging food, we encourage designing for recyclability over designing for compostability.
4. If compostability is important to you, look into paper packaging, which is recyclable and compostable, and is a material that biodegrades in virtually any situation - home composts, industrial composts or even as litter.
5. If compostable (non-paper) packaging is essential to your packaging strategy, be sure to ask your packaging partners the tough questions (Is the packaging certified? How many days to compost? Has it been field tested?) so you can fully educate your customers on how to dispose of their packaging. Avoid marketing messages that suggest the packaging biodegrades in a landfill or as litter or marine pollution. This type of marketing may encourage customers to dispose of packaging improperly.
6. Consider getting any compostable packaging you invest in field tested.
The idea of organic waste being successfully composted, resulting in high quality product that can be used as healthy soil amendment (ultimately resulting in richer soil that grows great produce and effectively sequesters carbon), is a pretty incredible thing.
With new, compostable materials and technologies coming on the market, we hope industry maintains a strong vision for the entire compost supply chain, designing not just for "certified compostability" but instead with a focus on composters' operations and economics, and ultimately how well resulting compost will enrich our lands and soils.