Study finds “forever chemicals” in reusable feminine hygiene products
Indiana University and Notre Dame researchers uncover PFAS in nearly 30% of tested items, raising safety and transparency concerns
Indiana University
BLOOMINGTON, INDIANA — A new study from researchers at the Indiana University Paul H. O’Neill School of Public and Environmental Affairs and the University of Notre Dame shows that per- and polyfluoroalkyl chemicals (PFAS)—also known as “forever chemicals”—can be found in reusable feminine hygiene products. The pilot study provides information that will be useful for consumers, regulators, and manufacturers.
Published in Environmental Science & Technology Letters, the article, “Per- and polyfluoroalkyl substances in reusable feminine hygiene products,” presents findings from Indiana University Associate Professor Marta Venier and her Notre Dame colleagues, who tested 59 reusable personal hygiene products from North America, South America, and Europe across several product categories—period underwear, reusable pads, menstrual cups, and reusable incontinence underwear and pads. Researchers found the presence of PFAS at levels consistent with intentional use in nearly 30 percent of the samples, the first confirmation of PFAS in reusable feminine hygiene products.
“Since reusable products are on the rise due to their increased sustainability compared to single-use products, it’s important to ensure that these products are safe. This is crucial, especially for adolescents and young women, who are more vulnerable to potential negative health effects,” Venier said. “Feminine hygiene products stay in contact with the skin for extended periods of time, and the risks from the dermal absorption of PFAS, especially neutral PFAS, are not well understood.”
PFAS are linked to serious health risks. While further studies are needed to define the risk of PFAS exposure to human skin, the study’s finding that at least one sample per category showed no intentional presence of these chemicals suggests that safer and healthier alternatives can be manufactured without them.
“One of the most abundant PFAS detected in products from the North American market is 8:2 FTOH, a chemical that was voluntarily phased out in food packaging by manufacturers in accordance with the FDA due to persistence in the body after dietary exposure,” said Sydney Brady, a Ph.D. student in Venier's lab. “Notably, 8:2 FTOH can be transformed into more toxic PFOA once inside the body.”
The use of reusable feminine hygiene products is on the rise to combat the environmental impact of disposable products, yet they eventually end up in landfills. Once there, PFAS can leach into the environment, creating broader, indirect exposure.
The study’s findings highlight the importance of transparency from manufacturers and the need for consumers to have access to information about the materials used in the products they purchase.
“Consumers should know that not everything that is in a product is listed on the package,” Venier said. “Increased transparency from manufacturers would help consumers make informed decisions about what they’re purchasing for themselves and their families.”
Journal
Environmental Science & Technology Letters
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Per- and polyfluoroalkyl substances in reusable feminine hygiene products
Article Publication Date
22-Jul-2025
Researchers at Notre Dame detect ‘forever chemicals’ in reusable feminine hygiene products
University of Notre Dame
image:
Notre Dame’s St. Andre accelerator, which is used to perform particle-induced gamma-ray emission (PIGE) ion beam analysis. (Photo by Matt Cashore/University of Notre Dame)
view moreCredit: (Photo by Matt Cashore/University of Notre Dame)
When a reporter with the Sierra Club magazine asked Graham Peaslee, a physicist at the University of Notre Dame, to test several different samples of unused menstrual underwear for per- and polyfluoroalkyl substances (PFAS) in 2019, the results fueled concern over chemical exposure in feminine hygiene products — which ultimately ended up in a $5 million lawsuit against the period and incontinence underwear brand Thinx.
Then in 2023, the New York Times asked Peaslee to test 44 additional period and incontinence products for PFAS, a class of toxic fluorinated compounds inherently repellent to oil, water, soil and stains, and known as “forever chemicals” for their exceptionally strong chemical and thermal stability. Measurable PFAS were found in some layers of many of the products tested — some low enough to suggest the chemicals may have transferred off packaging materials, while others contained higher concentrations, suggesting the chemicals were intentionally used during the manufacturing process.
In the meantime, another group of researchers published a study that found PFAS in single-use period products, leading Peaslee and his lab to widen their investigation into all sorts of reusable feminine hygiene products — often viewed as an eco-friendly option by consumers. Now, the results of that study have been published in Environmental Science & Technology Letters.
Most of the samples tested in Peaslee’s latest study (71.2 percent) contained PFAS concentrations low enough to be characterized by Peaslee and his co-authors as “non-intentionally fluorinated.” But period underwear (33 percent) and reusable pads (25 percent) had the greatest rates of “intentional fluorination.”
“The reusable menstrual product market is a rapidly growing market, which relies heavily on the idea that these products are environmentally conscious because of the significant reduction in the use of paper and plastic products,” said Peaslee, professor emeritus in the Department of Physics and Astronomy. “To the extent that they use organic textiles, these products are also marketed to consumers who are typically health and environmentally conscious. However, we found that almost a third of them were being made with PFAS. This means these products are both a risk to the wearer as well as to the rest of us when they are eventually disposed of, since we know that these forever chemicals persist when they end up in landfills, contaminating irrigation and drinking water systems for all of us.”
PFAS have been linked to several adverse health conditions including immunosuppression, hormonal dysregulation, developmental delays in children, low birth weight and accelerated puberty, high blood pressure in pregnant women, and an increased risk of some cancers, such as kidney and testicular cancer. The chemicals are so prevalent that the Centers for Disease Control and Prevention has reported that PFAS, a class of manmade chemicals, have been found in the blood of more than 99 percent of all Americans.
Peaslee and Alyssa Wicks, lead author of the study, who conducted the research while a graduate student at Notre Dame, tested more than 70 products sourced from multiple markets in North America, South America, Europe and Asia-Pacific, including period underwear, reusable pads, menstrual cups and reusable incontinence underwear. Each product was screened using particle-induced gamma-ray emission (PIGE) spectroscopy, an ion beam analysis in which a proton beam bombards the surface of the material being tested, causing fluorine nuclei to emit gamma-rays, a type of high-energy light to measure total fluorine content when detected.
For products with multiple layers, Wicks analyzed each layer of each product for a total of 323 unique samples tested using PIGE.
PFAS can migrate off treated surfaces, raising particular concern when used in reusable products that come in direct contact with the wearer’s skin. Previous studies at other institutions suggest skin absorption could be a significant pathway to exposure to certain PFAS.
Even with this latest study, Peaslee said, “there’s still a lot we don’t know about the extent to which PFAS are being used in the manufacturing of these products, and too much we don’t know about the potential for these chemicals to be absorbed through the skin by the consumers who wear them.”
Another significant discovery of the study, according to Wicks and Peaslee, is that currently only a fraction of the brands that make reusable feminine hygiene products use PFAS intentionally.
“Only a subset of the products had high levels of PFAS present, which means that PFAS must not be essential in the manufacture of reusable feminine hygiene products,” Wicks noted. “This is good news in that it demonstrates PFAS are not required to produce these environmentally conscious products, and manufacturers should be able to make these textile products without chemicals of concern in them.”
The authors deliberately chose not to identify PFAS concentrations by brand, but they hope the peer-reviewed study will help identify the need for ingredient transparency in the industry.
“While we do know that these chemicals have been linked to serious environmental and human health issues, we do not yet know what fraction of these PFAS make it into humans by direct exposure and indirect exposure at the end of life of these products,” Peaslee said. “What this study, and others to follow, can do is help consumers ask manufacturers the right question: ‘Does this product contain any intentional use of PFAS?’ Currently, there’s no labeling requirement for these products, and only a handful of U.S. states have drafted legislation requiring consumer products to be free of intentional PFAS use. This paper and others like it will help regulators and manufacturers alike to identify product markets where PFAS are being used and to find better alternatives moving forward.”
In addition to Wicks and Peaslee, co-authors who contributed to the study while at Notre Dame include Thomas Hedman, Heather D. Whitehead and Alison Zachritz. Additional co-authors include Marta Venier and Sydney Brady at Indiana University, Bloomington.
Journal
Environmental Science & Technology Letters
Article Title
Per- and Polyfluoroalkyl Substances in Reusable Feminine Hygiene Products
Article Publication Date
22-Jul-2025
