Forever Chemicals in Reusable Feminine Hygiene References and further readingHealth Alert and Scientific Insight

By Stayinghealthy !
Reusable menstrual products such as cups and period underwear, which were tested in a 2025 study revealing PFAS “forever chemical” contamination risks.
PFAS detected in 30% of reusable menstrual products, including cups, pads, and period underwear, according to a 2025 scientific study/ Pexels 


A groundbreaking pilot study by Indiana University’s O’Neill School and the University of Notre Dame has revealed that per‑ and polyfluoroalkyl substances (PFAS)—commonly known as “forever chemicals”—are present in nearly 30 % of reusable feminine hygiene products tested, including menstrual cups, period underwear, reusable pads, and incontinence wear .

 Study Overview

The peer-reviewed research, published in Environmental Science & Technology Letters, involved testing 59 reusable products sourced from North America, South America, Europe, and Asia-Pacific . The team employed two analytical techniques:

  • PIGE spectroscopy to screen total fluorine (a surrogate marker for PFAS) in 323 individual product layers.
  • Tandem mass spectrometry for in-depth analysis of 19 selected products, targeting 42 specific PFAS compounds.

 Key Findings

  • PFAS were found in 100 % of products when using sensitive methods; ~30 % showed levels (> 110 ppm fluorine) suggesting intentional use by manufacturers .
  • Some products, especially period underwear, contained extremely high fluorine levels—up to 1,000 ppm, consistent with waterproof coatings .
  • Average PFAS concentrations measured ranged from 21 to 2,200 ng/g, with a median around 380 ng/g .
  • The most commonly detected compound was 8:2 fluorotelomer alcohol (FTOH), which can transform into the more toxic PFOA within the human body .
  • At least one product in each category was PFAS-free, proving that safe, chemical‑free manufacturing alternatives are feasible .

 Health Implications & Knowledge Gaps

PFAS are long-lived, synthetic chemicals used for water-, oil-, and stain-resistance in everyday products—from nonstick cookware to fast-food wrappers . Extensive research links PFAS exposure to:

  • Endocrine disruption
  • Reproductive and developmental issues
  • Liver damage
  • Immune system impairment
  • Certain cancers

The main concern with reusable menstrual products is prolonged skin contact in sensitive areas, raising questions about dermal absorption and systemic exposure—especially via neutral PFAS like FTOHs, which may pass through the skin more readily . However, precise dermal uptake, toxicity threshold, and cumulative health impacts remain poorly understood.

Environmental Impact

While reusable products are marketed as eco-friendly alternatives, PFAS contamination introduces environmental risks:

  • Waterways & soil contamination — Discarded products or wash-off residues may leach PFAS into wastewater, persisting in ecosystems .
  • Lifecycle hazards — Used months before disposal means chemicals have extended exposure pathways to humans and wildlife.

Industry Response & Regulation

Manufacturers currently have no legal obligation to disclose PFAS, leaving consumers in the dark. The study emphasizes the need for:

  1. Mandatory labeling of PFAS presence, materials, and production methods in intimate hygiene products.
  2. Regulatory thresholds for PFAS levels in products worn in direct contact with skin.
  3. Transparency from manufacturers about raw material sourcing and chemical additives.

Notably, some products achieved high performance without PFAS, proving non-toxic design is possible. Additionally, lawsuits against companies like Thinx (NA-panted for period underwear) have triggered recall processes and ingredient transparency pledges .

Expert Voices

Associate Professor Marta Venier (IU): “Risks from dermal absorption of PFAS, especially neutral ones, are not well understood... adolescents and young women are more vulnerable.” 

Prof. Graham Peaslee (Notre Dame): “This means these products are both a risk to the wearer as well as to the environment when disposed of.” 

Ph.D. student Sydney Brady (IU): “8:2 FTOH can be transformed into more toxic PFOA once inside the body.” 

Postdoc Alyssa Wicks (Duke): “PFAS must not be essential in the manufacture of reusable feminine hygiene products.” 16

Practical Advice for Consumers

  • Choose products certified PFAS-free or explicitly labeled as chemical‑safe.
  • Consider menstrual cups or tampons, which consistently test PFAS-free in all layers 17.
  • Look for brands that publish material safety data or disclose chemical content.
  • Support legislation requiring full disclosure and safe manufacturing standards.

 Moving Forward

This study is a crucial first step but larger epidemiological and exposure assessments are needed. Priorities include:

  • Long-term monitoring of PFAS health impacts via dermal/external exposure.
  • Designing PFAS-free alternatives that match performance of current products.
  • Implementing strict labeling rules and enforcing legal limits for PFAS in intimate products.

Consumers, advocacy groups, and regulators should urgently come together to ensure menstrual product safety and sustainability.

References and further reading