June 18, 2008 | General

Operator Insights: Compostable Products

BioCycle June 2008, Vol. 49, No. 6, p. 41
Key factors to consider when choosing compostable products and lessons learned from integrating them into food scraps diversion programs.
Rhodes Yepsen

COMPOSTABLE products are increasingly a part of the formula when companies, institutions, municipal programs and special events decide to go green, usually to implement a food scraps diversion program. Due to increasing demand, the compostable products industry is growing rapidly, with many different options on the market. BioCycle has been covering developments in the compostable products industry since the early 1990s, and has observed the industry mature to the point where today there are widely recognized standards and certification programs regarding product compostability.
Along with the progress, however, are accompanying kinks that remain to be worked out, including the ability to distinguish compostable products from their conventional counterparts – and thus contaminate loads of otherwise fully compostable materials – as well as some confusion about the raw materials being used to manufacture the array of products. This month’s Operator Insights article explores these and several other issues, primarily from the perspectives of the generators and the composters.

The Sustainable Plastics Project (SPP), organized by the Institute for Local Self-Reliance (ILSR), was formed to research the biobased plastics market. This includes reports on companies that manufacture biobased plastics, and the origins of the resins used. SPP also provides information on early adopters of biobased products, and their practices. “The products we review are all biobased, not just compostable,” explains Brenda Platt, ILSR’s Waste to Wealth and SPP Director. “We look at what’s on the market, what products are being used and standards such as ASTM [American Society for Testing and Materials specifications].” This helps to identify areas of strength in the industry, as well as areas that should be addressed. For instance, notes Platt, standards don’t currently include ocean biodegradability, even though a lot of plastic ends up there.
“Just because something is made from biobased material, doesn’t mean that it was produced sustainably, or that it can be processed appropriately,” explains Platt. “What criteria will help consumers evaluate products on the market?” Another organization, the Sustainable Bioplastics Collaborative (SBC), of which Platt is a founding member, offers guidelines to help consumers navigate the maze of products. “The SBC guidelines define what qualifies as a sustainable biobased product, and include steps to best practice and things to avoid,” she says.
The four main guidelines for selecting sustainable products follow the lifecycle stages, with recommendations: Feedstock Production and Transportation (eliminate hazardous chemicals of concern, avoid GMO seeds, etc.); Processing and Manufacturing (avoid problematic blends, minimize hazardous emissions, etc.); Distribution and Use (reduce quantity of single-use products, purchase local, etc.); and, End of Life (ensure safe and rapid biodegradation, identify a composting facility, etc.).
“When large companies like Whole Foods and Kaiser Permanente decided to make the switch to compostable products, SBC provided baseline criteria for them,” says Platt. “For instance, we suggest purchasing 100 percent biobased products when possible – they’re on the market, so there is no reason to buy a fossil fuel blend. Purchase GMO-free, or participate in an offset program that supports sustainable agriculture. And purchase certified compostable.” Platt recommends using the Biodegradable Products Institute’s (BPI) guidance. The organization has a certification program for compostable bags, foodservice ware, resins and packaging. BPI approved products must meet ASTM 6400 or ASTM 6868, scientifically based certifications for compostable plastics. Platt encourages the support of BPI, instead of European standards, to help grow the North American composting infrastructure. SBC also offers “beyond baseline” criteria, which surpass these basic guidelines.
Although some products are available as 100 percent biobased, all compostable bags on the market have fossil fuel based products in them. In fact, the highest level of biobased content Platt found was 32 percent, with the average at 20 percent. “Compostable bags currently on the market are first generation,” says Platt. “The next generation will likely have more biobased material. I wouldn’t be surprised if within two years there were some on the market that are 80 percent biobased. It’s a balancing act between being compostable and maintaining strength.” For instance, Novamont, an Italian company that produces the resin Mater-Bi, is looking at biobased oil feedstocks such as rapeseed to increase this percentage.


Getting down to brass tacks, what are the major deciding factors for most generators? “Cost is always going to be preeminent, followed by quality, although each generator’s definition of quality is different,” says John Connolly, Principal of the environmental consulting firm JF Connolly & Associates. Quality may be purely about operational performance, whether in a bag, plate or cutlery. However, it may also include appearance, he says. “For instance, a high-end convention center doesn’t just need the product to perform well, but also needs the perception of quality and class for its guests.” One convention center Connolly worked with determined that black disposable cutlery connoted high quality, as opposed to the typical white. Some generators might not care what it looks like, as long it comes as close as possible to its metal counterpart.
“Clamshells for take out at a restaurant or supermarket – now you’re talking about the ability to stand up to temperature, moisture and heavy items,” he continues. “Restaurants and supermarkets have to ask, ‘How long will takeout sit in the refrigerator at home?’ That’s a factor for the useful life of the product.”
In terms of incorporating compostable products into a successful program, collaboration between the product user and the composter is of utmost importance, says Connolly, with both groups testing and signing off on the products. “Food waste diversion is a synergistic business partnership between the generator and the composter, more so than with a typical garbage business. It’s a rare vendor/customer relationship, where increasing services and volumes will actually increase profits for both parties. As the generator diverts more organics, they save more money, and the composter makes more.” One part of ensuring this successful business partnership is to strengthen the relationship between the generator and composter, instead of relying on the hauler as the middleman. “Communication between the generator and composter can make or break a program, especially when including elements like compostable products, which could be misinterpreted as contamination if the composter hasn’t approved and been a part of the selection process,” he adds.
As the compostable products market has evolved, Connolly has found that performance and appearance have generally improved, while costs have declined. Bags may be an exception – with regard to costs. “Bags have not come down in price as much as I would have expected, and may be as much as four times the price of conventional bags,” notes Connolly. However, because bags facilitate food waste diversion, the cost may be insignificant compared to the savings a program generates. “Using a biodegradable bag allows you to divert compostables out of the waste stream, significantly lowering your hauling bills,” he explains. “So the cost of the bags is not necessarily a factor if they are a critical part of the program.” Because they allow food scraps to be easily captured and separated, compostable bags have become a cornerstone for many programs.

The Independent School District (ISD) 196, in Rosemount, Minnesota, illustrates Connolly’s point. ISD 196 added compostable bags to its district-wide composting program. “Our district has 31 schools, with 28,000 students and 3,500 staff, and all cafeterias have food waste collection,” says Mike Schwanke, Coordinator of Facilities at ISD 196. “The initial reason for setting up our program in 2003 was to cut our hauling costs, but it was also for the educational factor, to demonstrate that we can’t be a throwaway society.” Originally, food scraps were put directly into containers in the cafeterias (not in bags) and then cocollected with trash (in bags). However trash bags in the truck often ripped open and contaminated the food waste, recalls Schwanke. “We added compostable bags to keep our feedstocks clean. After researching companies on the Internet, we chose Natur-Tec bags, because they were competitively priced, met BPI requirements and were a locally based company.” The captured food scraps are sent to Resource Recovery Technologies’ composting site, and he estimates that contamination, due to the bags, has dropped below five percent.
Compostable bags are also vital in King County, Washington. According to an informal survey (and feedback from residents), compostable bags encourage people to put more food waste in their yard trimmings carts, including potentially putrid foods that they otherwise would have avoided. “When we started our outreach, I didn’t think bags were necessary,” says Josh Marx, Senior Planner with the King County Solid Waste Division (SWD). “But I came to realize that we are a bag society, and that compostable bags are really the ticket to getting people to participate. Although there is still some perception that food scraps are icky and gross, bags help people realize that it’s not as bad as they think.”
King County first had to coordinate with Cedar Grove Composting, which receives the organics. Cedar Grove has a well-documented system for testing compostable products to ensure that every product it accepts will break down properly in its GORE system (tested products must first pass ASTM certification and be approved by BPI). Cedar Grove will only accept a compostable product once it has passed these rigorous tests. (For more information on Cedar Grove’s protocol, see “Biodegradable Plastics Make Market Inroads,” BioCycle May 2006.)
With the approved list of bags from Cedar Grove, Gerty Coville, Project Manager for King County SWD, spent eight months working with vendors. “We submitted a letter to local stores promoting these companies, and announcing the campaign to increase the use of compostable bags,” says Coville. “It’s called Market Transformation, and helps encourage stores to carry approved bags.” For one month, radio broadcasts advertised the availability of discounted bags at select stores. “We then provided staff at the stores on weekends to hand out free samples and answer questions about what can go into the bags and bin, etc.”
When families sign up for a new yard trimmings cart, sample bags and a brochure are delivered with the cart. Bags are also handed out at farmers’ markets in areas that recently adopted curbside collection of food scraps and yard trimmings. “The strategy is to put the tool in the hands of the residents,” says Coville. “Compostable bags are a way to get busy families to put food scraps in the yard waste container. Most residents are just beginning this, and don’t always understand what to do.” King County’s website offers advice and guidance, including a list of what bags are sold in which stores, organized by city.
Although Cedar Grove has approved compostable products besides bags, it is careful about allowing everybody to use them, including King County residents. “We have an approved list of other compostable products that we’ve tested, which is handed out on a case-by-case basis to interested parties,” says Jerry Bartlett of Cedar Grove. “We don’t publish the list because the products could quickly lead to complication issues, if not handled appropriately. The products are indistinguishable from conventional plastics, and so there needs to be dialogue, sitting down with the client and really explaining the list.” Unable to decipher whether products were approved or not, Cedar Grove would have to screen out all cutlery and dinnerware as contaminants. Special events, such as the festival at Marymoor Park in King County, are candidates for these additional approved compostable products.

Eco-Cycle, in Boulder Colorado, is no stranger to compostable products at special events. In fact, they pioneered a Zero Waste Kit, used at festivals, weddings and farmers’ markets. “About 10 years ago, we realized the need to switch from being a recycling organization to a zero waste organization,” says Dan Matsch, Program Manager for Eco-Cycle, Inc. “Besides helping to organize Zero Waste events ourselves, we sell the Zero Waste Kit, a Do-It-Yourself tool for events. The kits accommodate events from 25 people up to several thousand, and are customized for the occasion.” The standard kit, for 25 people, includes utensils, plates, cold cups, bags and a collection box with a liner. The box is reusable, and the cost of sending the material to the composter is built in.
When Eco-Cycle began its search for compostable products, there was no BPI or SBC for guidance. It developed a partnership with Eco-Products, a “green” distributor based in Boulder, as a means to have steady supplies of all the products needed for the Zero Waste Kits. “We partnered with Eco-Products to help build this market,” says Matsch. “They have worked hard at developing their own production line.” As far as price, Eco-Cycle feels it is well justified. “Yes, the cost for the products can be severe, but it’s the cost of getting this message out there.”

Eco-Cycle also developed a relationship with A1 Organics, the composting facility it utilizes. “We were upfront in the beginning about our mission, to get compostables out of the waste stream,” he explains. “A1 Organics realized they would have to make modifications to their process, that the materials are tricky to compost.”
Bob Yost, Vice President of New Business Development at A1 Organics, describes some difficulty with composting the bags in outdoor windrows. “Bags that are inside the pile break down fine, but those close to the edge or surface do not, which causes issues of site cleanliness,” says Yost, noting that the partially decomposed bags can become airborne when the piles are being turned. “Containers and flatware haven’t been much of an issue, but that may also be due to much lower volume of those items.”
Sharon Barnes confronts similar issues at her composting facility, Barnes Nursery in Huron, Ohio. “Pictures of our windrows will show more compostable plastic than you would want to see,” says Barnes. “This is not a problem with the bags, but the process. Products that meet the ASTM standards work well.” She over-bulks food waste loads to limit potential odors, leachate and vectors. This lowers the moisture content, which creates a less ideal environment for decomposition of the compostable bags. “Compostable products need 50 to 60 percent moisture to break down properly, and they’re not getting it,” she notes. This is especially true of material at the top of the piles, because the surfaces dry out faster. “When the windrows are turned or moved, wind spreads the plastic to clean piles,” adds Barnes.
To address the situation, Barnes plans on reorganizing the composting site, with a building for preprocessing food wastes inside, and windrowing the material in a separate area from windrows with just yard trimmings. “By mixing the materials inside we won’t have to worry about odor, and therefore won’t have to over-bulk, and can create optimum moisture levels,” she says. “That, combined with windrowing the food waste in an area distanced from the yard waste, will alleviate many issues.”
Confident that the challenges are manageable, Barnes encourages the use of compostable bags. The company is a distributor of BioBags, purchasing cases of bags and selling them at a loss, to encourage their use. Barnes recently sold a case to Oberlin College, helping to coordinate a sustainable commencement and alumni reunion. “The Alumni and Commencement weekend hosted about 8,000 people, with about 190 events, all of which were either served using china (preferred) or biodegradable products,” says Rick Panfil, General Manager for Bon Appétit Management Company at Oberlin College. “For instance, all of the pick up or late night events were served on bioware, which included cutlery, plates, trays, stir sticks (wood) and recyclable napkins.” After the event, food waste and compostable products were sent to the Barnes Nursery. Also, around 600 pounds of preconsumer food scraps were composted at the nearby Jones Farm, and around 200 gallons of waste cooking oil were sent to Full Circle Fuels (in downtown Oberlin) for biodiesel.
All compostable products used at the event were certified by BPI. These included Ecotainer cups and cutlery made from NatureWorks PLA. “Since the 1990s, we have been testing products for use and we have seen great improvement in the development of these products,” explains Panfil. “We are still investigating the viability of biodegradeable products as far as their impact on the environment. We are trying to tread lightly. If not properly composted, are the products really that much better for the environment?”
To limit contamination, five students at the larger events directed and educated the patrons. “We also bought special green garbage cans to identify where to put compostables,” notes Panfil. “The hardest part is getting everything out to the Barnes dumpster. There is always someone throwing something into a dumpster that doesn’t belong.”
With contamination at large events difficult to avoid, Connolly’s vision of a synergistic partnership between generator and composter rings true.

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