In the effort to reduce plastic waste in the restaurant industry — single-use takeout containers, specifically — University of Michigan researchers compared the lifetime environmental impacts of single-use and reusable food containers.
Their findings support the idea that the number of times a reusable takeout container gets used is a key factor impacting its sustainability performance.
Depending on the single-use container being replaced, the study found that the reusable alternatives — which initially use more energy and generate more climate-altering greenhouse gases — can break even with single-use containers after four to 13 uses.
“Reducing the quantity of single-use plastics in the restaurant industry by implementing reusable takeout container systems has the potential to reduce greenhouse gas emissions and save on energy, water and cost. Our study found that reusable containers can outperform single-use in all impact categories,” said study author Greg Keoleian, director of the Center for Sustainable Systems at the School for Environment and Sustainability.
The study, published online Jan. 5 in the journal Resources, Conservation & Recycling, reports that on a global scale, plastic production has accelerated dramatically over the past decades — leading to a sharp increase in plastic waste.
In the United States alone, more than 90 times the 1960 amount of plastic municipal solid waste was generated in 2018. Single-use packaging contributes millions of tons of plastic waste to that total each year.
In addition to the number of times that a reusable container is reused and the material type, the U-M study also found that customer behavior will be a significant factor in sustainability performance.
“If 5% of customers make trips by vehicle solely to return used containers, the reusable system has higher life-cycle greenhouse gas emissions than the single use,” said study co-author Christian Hitt, a dual-degree graduate student and Center for Sustainable Systems research assistant.
“We also looked at the water usage of at-home cleaning of the containers,” Hitt said. “Excessive washing can tip the balance against the primary energy impacts of reusable containers.”
According to the study, education will be key in counteracting these potential downsides by encouraging customer best practices. Informational labels on containers, signage in restaurants, employee dialogue with customers and online information are a few educational tools the study recommends.
Convenience can also play a part. City-scale systems with common containers across multiple restaurants may prove advantageous, as customers can return containers to different locations, decreasing the likelihood of customer travel for the sole purpose of container return.
As a base for their model, the researchers studied the pilot program for returnable takeout containers launched by the nonprofit organization Live Zero Waste in Ann Arbor. The program, Ann Arbor Reduce, Reuse, Return, is now in its second pilot phase and was implemented in partnership with the city of Ann Arbor’s A2ZERO carbon neutrality plan.
The research, which was supported by a Morgan Stanley Plastics Waste Reduction Research and Fellowship award, concludes that a reusable container system — as part of a circular economy strategy — offers the chance for significant benefits over time, if customers can be effectively educated to adopt sustainable behaviors.
In addition to Hitt and Keoleian, Center for Sustainable Systems research assistant Jacob Douglas was a co-author of the journal article.