Are Bioplastics As Good As They Seem?

from Wildlife Promise

By Leslie Wells

For universities hoping to reduce the amount of waste being sent to landfill, using bioplastics in cafeterias seems like a straightforward solution with notable benefits such as creating nutrient-rich compost for the university. However, new obstacles are emerging in regards to bioplastics, which may not break down as quickly as needed, and often confuse users who do not know how to dispose of them.

Commercial composting entails separating food waste and compostable plastics from other, non-compostable items and placing them into designated containers. Typically, these containers are picked up by a compost hauler on a weekly basis and mixed with yard clippings. This mixture must be heated to a very high temperature, around 160 degrees Fahrenheit, and turned and broken down by microbes for about six months to complete the breakdown process. The resulting product of this process can be sold as yard additive or returned to college campuses where they originated. This compost, when applied correctly, enriches the soil and helps to retain water. As new products made from corn, potatoes and other materials take the place of plastic, which doesn’t biodegrade, they can be added to this stream.

University of California Santa Barbara uses compostable bio-bags in addition to other products but, according to Bonnie Crouse, assistant director of residential dining services at UCSB, compostable items are often disposed of alongside non-compostable products, which may contaminate the whole batch. There is also the issue of expense: Mark Rousseau, UCSB’s energy and environmental manager, states, “Since it’s a new product, we understand, but it’s a hassle and expensive–11 cents versus 0.88 – 1.20 per bag.” 

Katie Maynard, sustainability coordinator for UCSB, says that universities generally face issues of health, sanitation, and pest management with composting. Concerns additionally arise regarding lengthy break-down time for some items labeled as compostable. Prior to 2008, the university only dealt with pre-consumer waste such as food scraps from the kitchens in its composting program. However, the new post-consumer pilot program has enabled the university to tackle bioplastics such as potato plates, cutlery, and cups, as well as meat and dairy products.

As bioplastics have developed, they have grown stronger, says Maynard. “When things are made sturdier, they take longer to degrade.”  She notes that cutlery, especially, has posed a challenge for the composting program. However, UCSB staff members are working with their composting hauler to more successfully compost a variety of bio-plastic products and have discovered that by shredding items before composting, these products will degrade successfully.

One key to UCSB’s success has been its ongoing communication between the waste hauler– Energy and Environmental– and staff members at UCSB, according to Crouse.  “The waste management company has been willing to take on and develop specific composting projects for our campus– including the testing of composting biodegradable disposables. This manager and the waste company team communicate regularly.”

At Tufts University, other challenges arise. Dawn Quirk, facilities department recycling coordinator of Tufts University, says that composting can cause confusion because students often cannot tell the difference between a biodegradable fork and a plastic fork, and do not know what to do with their waste. This can result in contamination of the compost waste stream, or improper disposal of items that are compostable.

Additionally, Tufts reports that some of the bioplastic cutlery has been removed from the compost stream because local farmers, ultimately responsible for the compost process of many local universities’ waste, are unable to tell if these items are biodegradable or not, and the items take too long to decompose.

To remedy these problems, Quirk hopes to better educate students about compostable products and states that special events have been held on campus to collect items such as bioplastic forks. In an effort to reach its goal of zero waste, Tufts may soon direct its attention toward providing students with small packages of reusable utensils and forgo bioplastics altogether.

Student confusion in composting has been a significant barrier to the University of Maryland’s composting program as well, according Mark Stewart, campus sustainability coordinator for the University of Maryland. The university recently invested in compostable bagasse products to replace Styrofoam trays in campus diners.  Stewart notes that “the switch to bagasse has gone fairly smoothly but it created a lot of questions from students about how to compost the containers.”

At Maryland, students can choose to eat in the diners using standard, reusable plates and cutlery, or take their food to go using the new bagasse containers. Stewart explains, “If students eat in the dining halls with bagasse (although they should be using plates), they can simply put the container on the conveyor belt and the dining service employees will put it in the compost bin. Alternatively, there are compost bins in the dining rooms so students can dispose of the containers and food waste there.”

The problem arises because students who take their food to go have no way to compost their trays once they leave the dining halls, meaning students must return the containers to the dining halls on their next visit. “As you can imagine, not many people do that,” says Stewart. He adds that he is working with dining services to expand composting beyond the dining facilities, but there are a lot of barriers to overcome.

Many composting programs are still in pilot phases and are researching solutions to remedy initial problems. One Massachusetts-based composting company, Save That Stuff, assists with composting at several in-state educational institutions such as Harvard, MIT, and Boston College. Adam Mitchell, a partner of the company, stresses the importance of using products that have been certified by the Biodegradable Products Institute (BPI). This institute has created a series of scientific tests to determine the compostability of biodegradable plastic products and ensure the quality of the resulting compost is not negatively affected by composting these products. If products pass the tests, the institute certifies them and marks them with a BPI-approved label, ensuring that products “will compost satisfactorily, including biodegrading at a rate comparable to known compostable materials…” and that the resulting compost will be of comparable quality.

Another key to success is ongoing communication between a university and its compost hauler.  Before implementing a composting program, Mitchell recommends that key players discuss the quality of the product produced, and plan to implement an effective training program for employees who will be involved in running the program. “Rubber gloves are one of the most pervasive contaminants we find in the food waste,” he states.  “Having a trash container near the food waste bins helps to prevent that. We’ve had success in taking the kitchen staff on a field trip to the compost site so that they understand what happens to the material after it leaves their kitchen.”

Mitchell further encourages universities to consider behind-the-scenes compost receptacles, rather than public receptacles, to avoid contamination of compost materials. Finally, Mitchell states, “The school needs a champion. While many schools have a recycling coordinator that’s housed in their facilities department, and that’s an important thing to have, the champion role should come from the food services department.  The second tier champion works best if the chef buys into the program.”