University of Wisconsin–Madison

Sustainability-based food service disposables

Project summary

Campus food service staff are interested in reducing their environmental impact and wanted to explore different types of disposable products and their possible benefits. Renewal of UW–Madison’s Disposable Food Service Supplies Contract in late summer 2016 offered the opportunity to integrate sustainability considerations into the product-selection process.

This project evaluated the carbon dioxide (CO2) emissions and relative impacts associated with more than 150 different disposable food service items.

Project partners

Office of Sustainability: Dakota Hitchner
Union South Dining Services: Carl Korz, Jim Long, Lisa Wadzinske, Verne Scholl
Facilities Planning & Management: Kris Ackerbauer, Lyle Jelle
Purchasing: Dave Brinkmeier
Waste Management: Betsy Hartje
Pellitteri Waste Systems: Tim Bolhuis

Project timeline

June – August 2016

Project status

ASSESSING PRODUCT IMPACTS

To guide the decision-making process, we created an Excel-based tool to compare CO2 emissions associated with different products. This Greenhouse Gas Calculator uses Environmental Protection Agency data on CO2 emissions associated with manufacturing and accounts for recycled content in products. The calculator is designed to assess disposable food-service items made of 11 different materials, including paperboard, sugarcane, and several types of plastic.

To use the tool, an individual needs only to know the product material, case dimensions and weight, quantity per case and the amount they are looking to buy. In this way, purchasing decisions can account for CO2 emissions without requiring extensive knowledge of emissions or climate science.

DISPOSAL SYSTEMS

A full evaluation of product impacts also requires an understanding of how recyclable and compostable material collected on campus are handled. UW–Madison’s composting system is based at the West Madison Agricultural Research Station. The material is managed in passive windrows with no additional heat inputs. In this type of system, inclusion of items such as compostable plastics would greatly slow down the time to produce finished compost. In addition, the compost stream coming from campus historically has contained a large amount of non-compostable material, including regular plastics.

The Union’s recycling contract is handled by Waste Management, which states that all collected recycling should be unbagged and free of food and liquid. Their policy is that material in opaque bags will be discarded and items in clear bags will only be recycled when there is sufficient labor to open the bags. Odors or obvious contamination with food or other material can cause an entire load be sent to the landfill. These policies are highly relevant for Union South. Recycling is currently collected in semi-clear bags. Since Union South sells predominantly food products, many of the collected recyclables may have food scraps or leftover liquid.

SUSTAINABILITY-BASED DECISION-MAKING

Observations have shown that most consumers do not remove food residue from food service products before discarding them, regardless of whether they place these items in the trash or recycling. This practice may lead to entire loads of recyclables going to the landfill. For items that end up in the landfill, associated CO2 emissions can be reduced by switching from plastics made with virgin material to plastics made from recycled content. One hundred percent recycled-content plastics reduce CO2 emissions during manufacturing by about 90 percent.

Compostable products are a second option. Compostable items can divert waste from the landfill, but they typically cost more and may release more CO2 during manufacture than traditional plastics. Additionally, many consumers have difficulty telling which products are compostable. This can reduce composting rates and, in some cases, contaminate recycling with compostable plastics.

Determining the best option depends on purchasing priorities and sustainability goals. For a purchasing team that wants to reduce landfill waste and is committed to continuing consumer education, compostable products may be the preferred choice. For a team interested in an easier, cheaper route that focuses on reducing CO2 emissions, recycled-content plastics may offer a better fit.

As a result of this project, campus food service units decided to purchase more compostable and recycled-content products. For example, Housing Dining now uses compostable takeout containers. Additional work is underway to improve consumer understanding of recycling and composting.