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University of Michigan researchers: Reusable products aren’t always best for environment

Just how green are reusable products?

Reusable straws.
Reusable straws. (Pexels)

ANN ARBOR – Over the past several years, sustainability-minded consumers have been shifting away from single-use plastics, opting instead for reusable products like beeswax sandwich wrap and bamboo drinking straws.

But when all is said and done, are reusable items truly better for the environment?

Researchers at the University of Michigan recently set out to answer that question, and were surprised by their findings.

For the study, they compared the lifetime environmental impacts of single-use plastics and reusable common kitchenware products, which they broke down into four categories: drinking straws, coffee cups, forks and sandwich bags and wraps.

They then determined the environmental “payback period” for reusable alternatives. This was calculated using the number of times someone must reuse a product before its impacts on the environment equal those of a similar single-use plastic item.

They were surprised to discover that some reusable products never break-even with their single-use counterparts because of the water and energy used each time it has to be washed.

For instance, beeswax wrap, silicone bags and bamboo drinking straws never reached that break-even point in these three environmental impact categories: water consumption, energy use and global warming potential.

The findings were published in the International Journal of Life Cycle Assessment on July 6.

“Reusable alternatives have quickly become a popular solution for replacing single-use products and helping to combat the ubiquity of disposable plastic,” environmental engineer at U-M’s Center for Sustainable Systems, Shelie Miller, said in release. “But don’t always assume that reusable is the best option.

“Our study showed that some reusable alternatives never break even because it takes more energy, and generates more greenhouse gas emissions, to wash them than it takes to make the single-use plastic item.”

Furthermore, Miller and first author of the paper, Hannah Fetner, reported that reusable alternatives that can only be hand-washed have higher impacts on the environment than products that can be washed in the dishwasher.

However, not all reusables were determined to be harmful.

They found that nine out of the 12 reusables did reach the break-even point, even if regular washing after each use was required.

“A key takeaway from our research is that we now understand what factors are driving environmental impacts for both reusable and single-use kitchenware products,” Fetner said in a release. “Knowing what factors are most influential can help consumers most effectively reduce their own impacts.”

In some cases, changing your cleaning practice could have a big impact on water and energy use, said Miller, who said simply rinsing out your ceramic coffee mug with cold water can make a difference.

“Not washing out a coffee mug after every use might ick some people out, but it’s actually a pretty standard practice for other folks,” Miller said in a release.

According to a release, other tips for best practices for consumers include:

  • Extend the reusable product’s lifetime as much as possible. The more times you use a product, the smaller your footprint.
  • When washing a reusable kitchenware product, choose machine dishwashing over hand-washing. In most cases, machine washing has lower impacts.
  • Reduce your overall consumption of these product types—both reusable and single-use versions. For example, some people need and benefit from drinking straws, while others could consider going strawless.
  • Advocate for the integration of renewables in your local energy grid and participate in green power purchasing programs when possible. Greenhouse gas emissions tied to heating water for dishwashing will vary with the carbon intensity of the local electrical grid.

To read the study abstract, click here.

About the Author:

Meredith has worked for WDIV since August 2017 and was voted one of Washtenaw County's best journalists in 2019 by eCurrent's readers. She covers the community of Ann Arbor and has a Master's degree in International Broadcast Journalism from City University London, UK.