“The notable finding from previous works [on PFAS] is how prevalent these chemicals have become in products we use regularly. But we haven’t really paid attention as to why PFAS are being introduced,” says the senior study author, Graham Peaslee, PhD, a professor emeritus at the University of Notre Dame in Indiana.
This is why the researchers looked specifically for higher PFAS levels that would indicate the chemicals were used on purpose (rather than low levels that would suggest environmental contamination) — likely to extend product longevity. The testing revealed significant PFAS levels in 1 out of every 3 reusable period products analyzed.
“This adds one more example of nonessential use of these specific chemicals,” says Dr. Peaslee. “There are plenty of products that don’t use PFAS at all, so they clearly aren’t required.” The study authors said the results indicate more research is needed on the potential effects of PFAS exposure through the skin.
When reached by email, a spokesperson for Thinx, a leading manufacturer of leakproof undergarments, referred Everyday Health to its “Clean Commitment List,” which outlines the substances intentionally excluded from its products, including PFAS. “We are committed to product safety and transparency as we continue to invest in rigorous third-party testing,” the spokesperson said.
Nearly All Reusable Period Products Contained PFAS
The study examined 59 reusable menstrual hygiene products from North America, South America, and Europe — including menstrual cups, reusable pads, and period and incontinence underwear — for the presence of PFAS (polyfluoroalkyl and perfluoroalkyl substances) chemicals.
Using a type of test known as total fluorine screening, the researchers found the highest presence of intentional PFAS use in period underwear (33 percent of all products sampled) and reusable pads (25 percent of products). Menstrual cups were the only category of product that had PFAS levels low enough to suggest the forever chemicals weren’t intentionally added.
What Are PFAS?
- Decreased fertility
- Developmental delays in children
- Increased risk of certain types of cancers
- Reduced immune system function
- Hormone interference
- Elevated cholesterol levels and obesity risk
“We don’t know much about dermal [skin] absorption,” says Dr. Venier. “But what we do know is that the genital area has very thin skin compared with other parts of the body, and so you can only assume that the absorption process will be enhanced because there’s less skin to go through.”
What’s Next for Future ‘Forever Chemicals’ Research
The study authors acknowledge that the study sample was small, and recommend larger, more comprehensive PFAS exposure studies across a broader range of personal hygiene products.
Andres Cardenas, PhD, MPH, an environmental epidemiologist and an assistant professor in the department of epidemiology and population health at Stanford University in California, says that the study illuminates the widespread contamination of PFAS in the broader U.S. supply chain — but more research is still needed, he says.
“While highlighting the extent of [PFAS] contamination of consumer products is very important, we still need to understand if dermal exposure from these products leads to any internal human exposure,” says Dr. Cardenas, who was not involved in the new study.
Carla Ng, PhD, an associate professor of chemistry, biology, and engineering at the University of Pittsburgh in Pennsylvania, says a helpful follow-up study could be “to test the blood of users of different products to see whether there is really exposure occurring from their use.” Dr. Ng was not involved in this study.
“What is clear,” Ng says, “is that these chemicals represent a risk of environmental release — for example, during the washing of products. In this way PFAS will continue to enter our waterways and broader environment.”
What to Watch for When Buying ‘Eco-Friendly’ Period Products
Experts are hopeful the findings will offer additional insight and empowerment for consumers who opt to buy these reusable products for sustainability reasons.
“In many cases, people are choosing to use these products over disposable products because of environmental benefits, and that is a good thing. But consumers may still need to look carefully at even more environmentally responsible products to try and reduce their exposures,” says Carmen Marsit, PhD, a professor of environmental health at Emory University’s Rollins School of Public Health in Atlanta who was not involved in the research.
But because PFAS aren’t listed on product labels, there’s no clear way for consumers to tell if they’re present — unless they do their own research, Venier says.
“I think one has to go by researching a specific brand and the brand’s position on PFAS,” Venier says. “It’s important that consumers are aware of this, because as they become more vocal, consumers can help move companies toward manufacturing products without these chemicals — if they want to keep that share of the market.”
For brands that don’t disclose a position on PFAS, Peaslee offers some helpful workarounds:
- Look for key words. Products advertised as nonstick, stain-resistant, long-lasting, or water-resistant are often associated with PFAS presence.
- Check the price. Peaslee says PFAS are fairly expensive to produce, so if you’re looking at two similar products, and one is noticeably less expensive, the cheaper option is more likely to be PFAS-free.
“We hope that publicity and market pressure will cause manufacturers that have PFAS-free products to add the words ‘PFAS-free’ to the product description. This can occur relatively quickly — like in less than a year — and it is testable and it will swing market demand toward a product without PFAS,” he says.