The period underwear brand Thinx recently settled a class action lawsuit claiming its products contain harmful chemicals. Graham Peaslee, Notre Dame professor in the Department of Physics & Astronomy, tested in Thinx underwear for these chemicals and Sierra magazine collaborated with Peaslee to published an investigation on the matter in 2020.
Period underwear is washable and reusable underwear designed to soak up menstrual blood. They are supposed to be an eco-friendly alternative to one-time-use pads and tampons. However, recent studies have shown that the presence of per- and polyfluoroalkyl substances (PFAS) in period underwear are harmful for the wearer and for the environment.
Peaslee used a particle-induced gamma-ray emission (PIGE) spectroscopy test to analyze the concentrations of PFAS in different brands of period underwear. He found a high peak for fluorine concentration, which is indicative of PFAS, in the inside layer of the Thinx underwear he tested.
Peaslee said PFAS are a class of highly persistent, bioaccumulative and toxic substances. These molecules last forever in the environment and accumulate in people’s bodies because they contain a strong carbon-fluorine bond that will never decay.
“All people in North America have about 5 [parts per billion] of PFAS in their bodies,” he said.
The issue isn’t so much the PFAS that is in products that we use and consume, but rather what happens to those products after we are done with them, Peaslee explained. The chemicals go into the landfill and don’t break down and eventually, they get into the water supply and our bodies.
“The scary part is that this molecule is everywhere and nobody realizes because the companies told us it was safe,” Peaslee said.
Jessian Choy, the freelance writer for Sierra magazine who broke the story about PFAS in Thinx underwear, said this is an issue that everyone should be worried about.
“This is an issue that affects all genders. It shouldn't just be people with uteruses clicking on this headline about menstrual underwear,” Choy said. “PFAS is getting into the water we all drink.”
Peaslee said that when these chemicals get into humans, they are attracted to fatty acid-binding proteins and are transported through the blood. Exposure to PFAS, even at low concentrations, has been shown to harm human health and several PFAS have been proven to cause cancer.
“We want to minimize exposure to these chemicals,” Peaslee said. “If it’s not essential, why are we using this molecule that may last forever?”
Choy explained that there is a lot of misinformation about PFAS. She said the idea that PFAS is everywhere, so it’s not an issue, is a misleading narrative.
“People are exposed to PFAS in their food and water, but that doesn’t mean that we shouldn’t try to reduce our exposure where we can,” Choy said.
She also said that many companies don’t tell consumers that their products contain PFAS. Even companies that say they have tested for PFAS may have only tested for some types and not all 9,000 plus variations.
Choy said that Thinx’s eco-friendly advertising was misleading because they were claiming to sell non-toxic products when they were using PFAS.
Peaslee agreed with Choy and said, “The company was claiming to be environmentally conscious, but they had anti microbials and PFAS in their underwear.”
Additionally, Choy said that some people thought the lawsuit was targeting a small company when Thinx is owned by Kimberly-Clark, a multibillion-dollar enterprise.
The news of the Thinx settlement brought renewed focus to the issue of the use of PFAS in period products and other consumer goods. Peaslee explained that attention has to be brought to an issue to enact change.
With regulation, "you’d have to have somebody poisoned before you can change things,” he said. “These articles will get people’s attention and they’ll be worried about [PFAS], and when people get worried then there’s attention focused on the industry and the industry will have to respond and make changes.”
Choy said that for PFAS regulations to be successful they need to be enforceable, which means there needs to be standards for product testing and staff so problems can be reported.
“I’m hoping that the general public will keep an eye on the laws that are being proposed to regulate PFAS and make sure that these laws have teeth,” she said. “We have to be our own best advocate.”
