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Biodegradable Pads Are Almost Here

Scientists developed a thin pad that breaks down in weeks, not centuries.

by Erene Stergiopoulos
May 17 2017, 5:10pm

Image: WALTER ZERLA/Getty

We've reached the beginning of a golden age for periods. The disposable tampons and puffy pads you grew up with are finally making way for sleeker, often greener options—be they menstrual cups, implausibly thin overnight pads, or polyblend period underwear.

The latest addition to the new breed of menstrual tech is the SHERO pad, made of organic cotton, algae, and corn. It's thin, biodegradable, super-absorbent, and took a team of engineers more than two years to develop.

It all started when Guatemalan non-profit advocacy group SHEVA contacted Jeff Bates about developing affordable and sustainable pads for local menstruators. Bates, an assistant professor in materials science and engineering at the University of Utah, does research on hydrogels—large molecules that are especially good at absorbing and retaining water.

The need for sustainable pads came from the reality that many people live in areas without public sanitation. They need pads that can degrade quickly, without adding toxins to local landfills and water systems. Plus, the scarcity of affordable and comfortable options means people are often managing their periods by staying home.

"One of the big pushes of that non-profit was education, making sure that women had access to feminine hygiene products so they could go to school, or so they could work," Bates says. The result of two years of research and testing is a pad that's biodegradable, sustainable, and vegan. Its outer layer is made of raw cotton—similar to the material in tea bags—and it wicks liquid away from the body and down to the pad's inner layers. The second layer is organic cotton, and transfers moisture to the third super-absorbent hydrogel layer made of agarose gel—or brown algae. The final layer is made of corn-based material, and keeps liquids from leaking out.

Depending on moisture conditions, the SHERO pad can decompose in as little as a week, or can take up to three months. (The typical drugstore pad or tampon takes centuries to biodegrade.) To settle on their final product, Bates and his team of students had to test a huge range of synthetic hydrogels. But they kept hitting a wall. "I was looking at the chemicals they were degrading into," Bates said. "You know, these are carcinogenic, these are toxic for water systems—and I was thinking, I don't like any of this."

Then came the night when Bates was eating dinner with his five-year-old daughter. She spilled rice on the floor, and instead of cleaning it right away, Bates (who assures me his house is otherwise usually very clean) decided to leave it until morning, when it had dried, and was easier to clean up. "As I was driving into work the next day, I was thinking about all the properties of cooked rice after it's dried out," Bates says. "And I was realizing, I think we could use this as a hydrogel material." That realization shifted the project into a different gear, leading the team to develop the SHERO pad in its present form, which is entirely plant-based.

The team has plans to offer the pad to communities in the Global South, where the existing cheap and sustainable options are limited to pads made from banana fibre, which are thicker and less comfortable than the typical drugstore pad. "We've explored everything from microfranchizing women in developing countries, to even creating a recipe book women can use to manufacture their own products," Bates says. The added advantage of using plant-based materials is that they can be locally sourced and manufactured cheaply and easily using presses and grinding stones.

They're also aiming to target US consumers looking for sustainable period solutions, with plans to release SHERO pads through a period subscription box by August 2017, pending FDA approval. From there, they'll collect feedback from customers for further R&D, and they hope to have their pads on shelves within a year.

After pads, Bates and his team are also working on developing tampons and liners. The project offers its own set of challenges, especially considering the risk of toxic shock syndrome (a life-threatening bacterial infection) associated with super-absorbent tampons. "In our work, we have discovered that boiling cotton makes it more absorbent and it sterilizes it," Bates says. "Therefore, there is no need to use any harsh chemicals in tampon manufacturing. We have thought about it to that extent, and I'm sure we'll come up with more risks and natural processes as we move to that part of our work."

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