PFAS and Period Underwear: Why Testing and Transparency Matter
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PFAS and Period Underwear: Why Testing and Transparency Matter

by Madeleine S.
PFAS and Period Underwear: Why Testing and Transparency Matter

With consumers becoming increasingly concerned about the level of exposure to human-made chemicals called per- and polyfluoroalkyl substances (“PFAS”) in their drinking water, household products and yes, period underwear, we felt it was important for Aisle to share our position and track record on the presence of PFAS in our products. 

At Aisle, our dedication to quality, sustainability and product safety border on being obsessive. In fact, the company was originally founded to create products that were free of allergens, bleaches and other irritants. The explosive popularity of reusable menstrual products in recent years has led to concern around the presence of PFAS in period underwear. Let’s take a closer look.

What are PFAS?

Per- and polyfluoralkyl substances, or PFAS, are a large, complex group of chemically manufactured compounds made up of a chain of carbon and fluorine atoms. The carbon-fluorine bond is a uniquely strong bond and causes PFAS to have non-stick qualities that make them water and stain resistant. 


Often referred to as “forever chemicals” because they do not break down in the environment, PFAS can be found in food packaging and apparel. While there are over 3000 types of PFAS compounds, most commercial laboratories will test to detect the top 20 to 30 PFAS compounds of concern.

Products that contain PFAS

Why is exposure to PFAS potentially harmful?

There is growing scientific evidence about the potential adverse health impacts associated with PFAS exposure, including liver damage, thyroid disease, decreased fertility, children’s developmental delays, high cholesterol, weakened immunity, hormone disruption, and cancer.

Are PFAS present in Aisle products?

At Aisle all our fabrics come with STANDARD 100 by OEKO-TEX® certification and have therefore been tested for numerous harmful substances by independent agencies using global standards. This includes a growing list of PFAS and applies to every part of our garments: a standard we have adhered to for decades.

In addition to these certifications, we regularly send sample products to SGS - a leading testing and inspection company - for PFAS testing. We are pleased to report that the tests we have conducted have reported no detectable* levels of PFAS (* based on a detectable limit of one part per million. See SGS test results below.)

But don’t just take our word for it. Aisle period underwear was independently tested by the Sierra Club and Mamavation. Both times our period undies received a ‘clear’ or ‘best’ rating. 

"for those of you still looking for safer alternatives (...) Aisle is the only organic menstrual underwear that was tested twice to be free of PFAS by secret shoppers (yours truly and consumer watchdog Mamavation)."

These consistent test results reflect our commitment to not use any PFAS-based treatments to our fabrics or products. 

What does “PFAS-free*” period underwear really mean?

According to scientists we have talked to, it is technically impossible to say that anything is “PFAS-free. This is because millions of different types of per-and polyfluoroalkyl substances and fluorines exist ubiquitously at infinitesimally microscopic levels. 

Hundreds of studies have been written on this topic: there is essentially no way of avoiding some or trace levels of PFAS in most everyday household items, thanks to their ‘forever’ quality.  Given this, consumers should not accept blanket statements from brands claiming that their products are PFAS-free. 

Rather, they should check whether the product has been independently tested and whether there is transparency in disclosing the amount of PFAS in the product. As for what an acceptable level of PFAS is “safe”, we are not scientists. Instead, we rely on experts in this field to set a high enough bar on what is deemed to be an acceptable level of PFAS detectable in consumer products. Aisle will always take steps in our product development process to ensure the highest standards of care when manufacturing period products for our customers. 

Still wondering “are period underwear safe?” 

We recommend you do the research, request evidence for transparency, and only choose products that have been independently tested by established, accredited professionals. 

You can view our PFAS testing results by clicking the reports below:

Test results for Aisle BASE underwear

Test results for Aisle BOOST underwear & Aisle Pads

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