The Short Answer
In independent testing, 65% of period underwear brands were found to contain fluorine, a strong indicator of toxic PFAS "forever chemicals." Brands like Thinx and Knix have faced major class-action lawsuits after alarmingly high levels of these chemicals were discovered in the crotch area of their products. Is There Pfas In Period Underwear
If you want safe, PFAS-free period underwear, you should only buy from brands with verified third-party non-detect lab results like Saalt, Modibodi, and The Period Company. The good news is that toxic coatings are completely unnecessaryā35% of the market proves you can make effective, leak-proof underwear without them. Safest Period Underwear
Why This Matters
PFAS (per- and polyfluoroalkyl substances) are synthetic chemicals that do not break down in your body or the environment. They are incredibly effective at repelling water and resisting stains, which is exactly why they are heavily used in the moisture-wicking gussets of traditional leak-proof underwear. Period Underwear Vs Pads
Your vaginal tissue is highly vascular and absorbs chemicals straight into your bloodstream. Studies have linked persistent PFAS exposure to serious health issues, including reproductive problems, hormone disruption, and weakened immune systems. You do not want these chemicals anywhere near your most sensitive skin. Is Period Underwear Safe
Many brands falsely market their products as "organic" or "toxic-free" while hiding behind inadequate testing. Thinx settled a $4 million class-action lawsuit in 2023 after independent tests found up to 3,264 parts per million (ppm) of fluorine in their "organic" briefs, proving that marketing claims mean nothing without transparent lab verification. Does Thinx Have Pfas
What's Actually In Period Underwear
- PFAS (Forever Chemicals) ā Used to make the gusset waterproof and stain-resistant. Linked to endocrine disruption and reproductive toxicity. Which Period Underwear Has Pfas
- Silver Nanoparticles ā Often added as an antimicrobial agent for odor control. Can disrupt your natural vaginal microbiome. Is Silver In Period Underwear Safe
- Polyurethane Laminate (PUL) ā The breathable plastic layer that stops leaks. Generally safe, but requires careful manufacturing to avoid chemical contamination.
- Synthetic Fabrics ā Materials like polyester and nylon are common for moisture-wicking, but can trap heat and breed bacteria if worn too long.
What to Look For
Green Flags:
- Non-Detect Fluorine Tests ā Brands that publish independent lab results showing 0 ppm of organic fluorine.
- OEKO-TEX Certification ā Ensures the final product is tested for a wide range of harmful substances.
- Organic Cotton ā Reduces your exposure to pesticide residue in the absorbent layers.
Red Flags:
- "Stain-Resistant" Claims ā This is often industry code for a chemical PFAS coating.
- Antimicrobial Treatments ā Often rely on heavy metals like silver or copper nanoparticles that can irritate your skin.
- Vague Safety Claims ā Saying "we follow all regulations" isn't enough when PFAS are largely unregulated in clothing.
The Best Options
Here is how the most popular brands stack up based on independent lab testing by consumer watchdogs like Mamavation.
| Brand | Product | Verdict | Why |
|---|---|---|---|
| Saalt | Period Underwear | ā | Tested completely clean for organic fluorine in 2023. |
| Modibodi | Period Underwear | ā | Zero detectable fluorine and uses sustainable bamboo and merino wool. |
| The Period Company | Period Underwear | ā | Highly affordable and verified PFAS-free by third-party labs. |
| Knix | Leakproof Underwear | ā ļø | Currently facing lawsuits over PFAS detected in independent testing. |
| Thinx | Period Panties | š« | Settled a $4M lawsuit after independent tests found up to 3,264 ppm of fluorine. |
The Bottom Line
1. Verify third-party testing. Do not trust a brand's own marketing claims about being "PFAS-free." Period Underwear No Pfas
2. Upgrade to clean brands. Switch to verified clean options like Saalt or Modibodi to protect your health. Is Saalt Period Underwear Clean
3. Wash before wearing. Always wash new period underwear before the first use to remove any residual manufacturing chemicals.
FAQ
Are all period underwear brands contaminated with PFAS?
No, 35% of brands tested completely free of detectable fluorine. Companies have proven that it is entirely possible to make effective, leak-proof underwear without using toxic "forever chemicals."
Did Thinx change their formula after the lawsuit?
Thinx agreed to stop intentionally adding PFAS as part of their 2023 settlement. However, consumer trust is low, and many health advocates recommend switching to brands with a longer track record of clean testing. Is Thinx Safe
What about Knix?
Knix claims their products are 100% PFAS-free, but independent testing in 2021 found 373 ppm of fluorine. They are currently facing a class-action lawsuit over deceptive marketing, making them a brand to approach with caution until further independent testing proves otherwise. Is Knix Clean