Knix Review, Is Knix Non-Toxic?
PFAS Authority is a scoring system, not a laboratory. We do not test products ourselves. Grades are model-based, built from published ingredients, materials, certifications, brand disclosures and third-party lab results where they exist. See the rubric.
Across 3 graded products, Knix averages Poor (25/100). On disclosure, the brand says nothing publicly about PFAS. None of its products grade Good or better yet. Grades are model-based estimates, not lab results.
Graded and flagged Poor and Bad, we’d swap these
Knix
SuperPlus Leakproof No- Show High Rise Underwear
Cotton/synthetic blend with proprietary waterproof/leak-resistant coating (unspecified)
Undisclosed waterproof coating chemistry (likely fluorinated or silicone polymer)
The proprietary coating is necessary for leak resistance but Knix has not publicly named…
Coating degradation and microparticle shedding with repeated wash cycles
Synthetic waterproof coatings on textiles degrade gradually with laundering, especially…
Skip unless Knix discloses waterproof coating chemicals.
⚠Waterproof or stain-proof treatment
Knix
Women's Super Leakproof Dream Boxers
Fabric with waterproof/leak-resistant coating (unspecified chemistry)
Teflon-type coating or fluorochemical fume risk (if Teflon-type coating-based coating)
If the waterproof layer contains Teflon-type coating, heating during machine wash or body…
Microplastic shedding from coating degradation
Repeated washing and wear will eventually degrade any synthetic coating; fragments may…
Coating leachates during wear or washing
Unidentified coating chemistry could include plasticizers, binders, or processing…
Lack of product lifecycle or end-of-life guidance
Knix does not provide instructions for safe disposal of worn-out underwear or clarify…
Skip until Knix discloses coating chemicals or independent testing.
⚠Waterproof or stain-proof treatment
Knix
Medium-Flow Leakproof Period Underwear
Organic cotton/viscose with proprietary waterproof coating (unspecified)
Undisclosed waterproof coating chemistry
Knix does not publicly identify the waterproof polymer or treatment agent used.…
Skin sensitization from dyes or finishes
Organic cotton base reduces pesticide risk, but the waterproof coating may contain…
Coating degradation and leachables over time
Repeated washing and body heat can compromise the integrity of applied coatings. As the…
Waterproof period wear with undisclosed coating creates uncertainty.
⚠Waterproof or stain-proof treatment
Every grade uses the same public rubric. How grades work →