The store front of Zingermanns on a cloudy day. In the window, an open sign is lit up.
Ellie Vice/Daily. Buy this photo.

University of Michigan researchers published a sustainability-focused study in January 2023, comparing the environmental impacts of reusable plastic containers to single-use containers. The researchers studied a program launched by the non-profit Live Zero Waste in Ann Arbor where customers can request a reusable carryout food container from a participating business. Customers then have to clean the container after use and return it back to the business whenever they have time. Several local restaurants such as Zingerman’s Next Door Café, El Harissa, Ginger Deli and Cinnaholic participate in the program.

The researchers evaluated elements of the program such as cost, water use and consumer behavior to determine whether using a reusable container was more sustainable than single-use takeout boxes. Their results determined that on the surface, reusable containers have lower environmental impacts than their single-use counterparts. The study flagged that the emissions from the transportation required to return the reusable containers might make them less sustainable than they seem.

According to Samuel McMullen, the executive director and co-founder of Live Zero Waste, Zingerman’s initially came up with the idea of offering reusable takeout containers in 2021 to support Ann Arbor’s commitment to carbon neutrality. Because of the city’s previous environmental and recycling initiatives, McMullen said he believed Ann Arbor was the perfect place to pioneer the program. The nonprofit Recycle Ann Arbor collects curbside recycling throughout the city and strongly encourages citizens to reuse materials when possible. McMullen said Live Zero Waste was able to work with Recycle Ann Arbor to pilot their program.

“We have a really unique opportunity in Ann Arbor to work with the recycler, which opens up just so many logistics opportunities,” McMullen said. “They already have trucks. We could, in (the future), collect recycling and returnable containers on the same routes. It’s a huge opportunity that very few other places in the country have the ability to test.”

McMullen said businesses that have regular customers are ideal candidates for the program because if they make the switch to reusable containers once, they may be more likely to continue to use them when coming back for another meal.

“El Harrisa has been a really high performer,” McMullen said. “They do north of 50 containers a week. They also have good regulars which is something that really lends itself to a restaurant with a sort of similar clientele coming back because they can make returning their containers part of their habit.” 

The program has been around for two years, but until now there hasn’t been any research on how much it’s actually helping the environment. The January study was co-written by Environment and Sustainability graduate student Christian Hitt and Engineering graduate student Jacob Douglas under the guidance of Gregory Keoleian, Engineering and SEAS professor. The researchers found that after just five — or in some cases, fewer than five — uses, the reusable containers had a net positive impact on the environment over disposable ones.

However, if customers started making additional trips to return the containers to restaurants, the program could harm the environment more than it helps. The researchers found that if even 5% of customers made an extra car trip to return their takeout containers, the program would contribute more greenhouse gasses to the atmosphere than single-use containers.

Douglas said he believes the program would work best in a walkable city where customers could return their containers without creating any additional emissions.

“If you’re in a rural area, and people are driving 10 miles just to return their container, (reusable takeout containers are) going to be way worse than just having disposable containers,” Douglas said. “But if you’re in a city where people could walk and return the containers then the system can be a little bit more flexible.”

Douglas said the research team was not able to find out how many times containers can be reused before they break or become unusable. 

“There’s the potential that they can be reused like hundreds of times, but in all likelihood, they’re not being reused that many times and people might steal them or they might break them,” Douglas said. “If the container gets reused many times, that’s sort of the best-case scenario.”

Going forward, Hitt said the team is looking into different types of materials that could be used to make reusable containers as durable and sustainable as possible.

“One of the big ones we’re looking at is bringing in different types of reusable materials such as stainless steel,” Hitt said.

LSA sophomore Melissa Oz, a student ambassador at Planet Blue, a campus organization focused on sustainability at the University, said though she hasn’t used the program yet, she thinks it could be an environmentally-friendly option for students who walk downtown to get takeout at the participating locations.

“Everyone gets takeout because no one wants to eat in a little area that’s not conducive to studying,” Oz said. “I think it’s really cool that people are trying to make it more sustainable because I do get a little guilty every time I get a Styrofoam container.”

Daily News Reporter Isabella Kassa can be reached at ikassa@umich.edu.