Our Approach to Product Testing and Safety

At Knix we are proud that our customers trust us with their bodies. They trust us to
photograph them as part of our campaigns, they trust us to share their stories, and above all—they trust us to make intimates that are comfortable, safe, and effective.
As part of that trust we are committed to doing everything we can to ensure that we do not intentionally use toxic or harmful chemicals in our products and to be open and honest about what, exactly, that promise means. We began routine testing for certain per- and polyfluoroalkyl substances (PFAS) in our leakproof fabrics and leakproof products back in January 2020 when questions began to arise in the global community regarding a potentiallink between the period underwear category and PFAS given the water-repellent nature of certain products in that category. Shortly thereafter we began testing for organic fluorine (the “F” in PFAS).

We have been sharing examples of our test results with then Knix’s community since
January 2020 and will continue to do so. To skip to see sample results please scroll
down to the bottom of the blog post. These results are from leading testing labs, and
what you will find when reviewing them is that neither PFAS nor organic fluorine was
detected at the testing limits. We will continue to routinely update our blog so you can seethe results from our most recent testing, which is part of our quality procedure.
Our most recent test results from August 2026 reflect alignment with global standards set by the AFIRM Group Restricted Substances List (RSL). For targeted PFAS testing, our
laboratory detection thresholds align with AFIRM's strict limits of 0.01 to 1 parts per million(ppm) equivalent to 10 to 1000 parts per billion (ppb) for individual chemicals. Additionally,for broader organic fluorine screening, testing was benchmarked against a threshold of 20ppm.

Doing the real work to ensure that our leakproof products are safe, and that our consumers understand the science, is no small feat. We will continue to monitor the complex and ever-changing world of PFAS – a vast number of chemicals that the government,researchers, and companies are still struggling to fully define and understand.

These complexities are part of the reason that we have publicly advocated for increased
PFAS regulation and education. The bottom line is that the best we can do at Knix is to
source quality materials and test them along with finished leakproof garments to help
ensure intentionally added PFAS are not used in their manufacturing. Knix, or any company for that matter, cannot promise that a product will make it to customers PFAS free because of the omnipresence of PFAS in the environment (they can be found in water, air, soil and even breast milk) and the supply chain, which creates the potential for trace levels of PFAS or PFAS-like chemicals to inadvertently find their way into products.

Let’s begin by sharing a high-level overview of our sourcing and testing protocols for our leakproof products:

• It starts with an effort to source quality fabrics, which are evaluated by an independent
third-party lab for targeted PFAS as well as for total organic fluorine. Only fabrics that meet our strict standards are used.
• We contractually prohibit our manufacturing partners from using intentionally added PFAS during manufacturing as well as require them to attest that they are conducting their own quality controls.
• We test our products regularly in alignment with AFIRM Group Restricted Substances List(RSL). PFAS Analytes as well as for total organic fluorine.
• We routinely share testing results from our spot testing for finished products here on this blog. To see sample results please scroll down.

What are PFAS?

Although the exact definition varies around the globe, PFAS (per- and polyfluoroalkyl
substances) is a term commonly used to refer to a large number of synthetic chemicals
that have carbon and fluorine bonds. PFAS are used in wide array of commercial and
industrial products, and they have historically been used in the textile and apparel industry as a stain or water repellent. The two most commonly discussed PFAS
are PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonate), but according to the United States Environmental Protection Agency (EPA), there are over twelve
thousand different PFAS out there. Research is still ongoing to identify, test and
understand the potential human and environmental health impacts of these substances.

While it is not currently feasible to test for all 12,000 PFAS directly, we do know
that all PFAS contain organic fluorine (this is the “F” in PFAS). Organic fluorine is typically
synthetic and is one known PFAS marker. It is not to be confused with inorganic fluoride,
which is found naturally in many minerals and other materials (including toothpaste and
drinking water) and does not indicate the presence of PFAS. What does this mean? Testing for organic fluorine is the most efficient way to screen products to determine whether they may contain any of the thousands of different PFAS.

We Do Not Add PFAS

At Knix we do not intentionally use PFAS in the manufacturing of our leakproof products.
However, PFAS are now so widely dispersed in the environment that even drinking water
often contains low-level contamination that is difficult to completely eliminate. These
fluorinated compounds are also persistently present throughout supply chain processes,
including the cleaning solutions and water commonly used on manufacturing equipment.

Knix maintains strict control over the safety and quality of the materials used in its
leakproof products. For instance, Knix enforces a multi-step quality assurance process to
prohibit our third-party textile suppliers from using intentionally added PFAS in the fabrics they supply to us:

• First, we prohibit all our materials suppliers for leakproof products from using intentionally added PFAS, and require them to attest that the products and materials they supply to us do not contain intentionally added PFAS.
• Second, we require our suppliers to perform their own quality control testing for PFAS and organic fluorine.
• Third, we independently test the fabrics in our leakproof products for organic fluorine – the key indicator of PFAS. Any fabrics that fail to meet these rigorous standards is immediately rejected and will not be used by Knix.

Knix’s PFAS & Organic Fluorine Testing
PFAS Testing
Before January 2020 PFAS was not generally a topic connected to our product category andas a result we had never tested our products for PFAS or made any public claims related to PFAS. However, in early 2020, as awareness of PFAS grew stronger in our industry, Knix,initiated additional third-party testing for peace of mind. At the time, this standard testing scanned 20-30 main PFAS variants (including PFOA), which our Leakproof Underwear were cleared for. You can view our recent “non-detect” test results at the bottom of this page. Fast forward to today, Knix partners with an industry-leading lab and experts that guide our PFAS testing, including testing for a wider array of PFAS.

Organic Fluorine Testing

In January 2020, upon learning that all PFAS compounds contain organic fluorine, we
expanded our safety protocols by testing our Leakproof Underwear fabrics for fluorine
alongside our standard PFAS testing. Fluorine screening has been an integral part of our
quality process ever since. At the bottom of this post, you can view “non-detect” fluorine
results across leakproof, super leakproof and cotton super leakproof.
A quick note on science: there is a key difference between organic fluorine and inorganic
fluorine. If lab test for “total fluorine” some harmless components can skew the results
even when no PFAS are present. That is why it is critical to look specifically for organic
fluorine testing when evaluating PFAS exposure.

What’s Next
Having launched in 2013, we pride ourselves on being pioneers within the period
underwear and leakproof underwear industry and as such we are leading by example— by calling for more transparency and stricter regulations in this growing category. Our work is ongoing, but we want to include you in our journey to address this PFAS issue in
meaningful and informative ways.

Thank you for trusting us to make your intimates. If you have any other questions about
product safety, please don’t hesitate to reach out to our team at info@knix.com.