HOKA · Running & Athletic Shoes
Hoka Men's Clifton 9 GTX
GTX waterproofing likely contains PFAS; Hoka provides no disclosure.
Hoka's Clifton 9 GTX uses Gore-Tex waterproofing, a Teflon-family coating membrane typically containing PFAS. The brand discloses nothing about PFAS content or alternatives.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Mesh/knit upper, GTX waterproof membrane, rubber outsole
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What Hoka Men's Clifton 9 GTX is made of, ingredients and materials
The Clifton 9 GTX uses a knit mesh upper paired with Gore-Tex (GTX) waterproof membrane and rubber outsole. Gore-Tex is a Teflon-family coating laminate engineered to repel water while allowing vapor transfer; the fluorine chemistry raises PFAS concerns because Gore-Tex has historically used perfluorinated compounds, though Gore has not publicly confirmed PFAS-free alternatives for this product line. The rubber outsole itself is not a primary chemical hazard vector. Mesh uppers are typically polyester or nylon blends, which can carry residual dyes and finishes but are lower-risk than coated synthetics.
What’s concerning
Waterproof / stain-resistant treatment
Water-repellent coating treatments have historically used PFAS.
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
PFAS
Gore-Tex membranes have historically relied on perfluorinated compounds; Hoka provides no product-specific disclosure or commitment to PFAS-free alternatives on this model. Wear and washing may mobilize trace fluorinated residues into soil or water over the product lifetime.
Source, ATSDR ↗Azo dyes and synthetic colorants in mesh/knit
Polyester or nylon mesh uppers may contain azo dyes which, though regulated in most Western markets, can degrade to aromatic amines under sweat and UV exposure. No OEKO-TEX or similar test certification is advertised for this shoe, leaving dye safety unverified.
Formaldehyde / VOCs
Textile finishing for wrinkle resistance, crease-setting, or softness on knit uppers may involve formaldehyde-releasing resins. Industry standard but not disclosed by Hoka; off-gassing risk is low in footwear due to aeration during use but cannot be ruled out in storage.
Source, ATSDR ↗Microplastics
Rubber outsoles shed microparticles during normal wear and accelerate under wet or abrasive conditions. This is a category-wide issue affecting all synthetic running shoes, not unique to Hoka, but worth noting if environmental impact is a concern.
Source, EPA ↗What’s reassuring
Antimony in polyester dyeing catalysts
If polyester is used in the upper, antimony-based catalysts may be present in trace amounts from synthesis. No record of antimony contamination in Hoka footwear; this is a general polyester concern, not product-specific.
How is this PFAS grade calculated?
The brand's record and disclosure
Hoka (owned by Decathlon Group) has not issued public PFAS disclosures or commitments specific to waterproofed footwear. The brand does not advertise third-party certifications (e.g., OEKO-TEX, Bluesign) for textile safety on this model. No major safety recalls or textile hazard controversies are on record for Hoka footwear. Decathlon Group has published some sustainability goals but does not detail chemical phase-out plans for Teflon-family coating in end-consumer products.
How it compares in its category
Running shoes with Gore-Tex or equivalent membrane waterproofing are commonplace; all major brands (Nike, Asics, Brooks, Salomon) use similar technologies. Membrane-free alternatives exist (standard mesh with drainage design, or sealed seams without Teflon-family coating) but sacrifice water resistance. The Clifton 9 GTX is positioned mid-premium; it does not claim to use emerging PFAS-free membrane technologies such as polyurethane or silicone-based systems that some specialty brands now market. In PFAS transparency, it is below category median because Hoka remains silent.
If you buy it
Wash by hand in cool water with mild detergent after muddy or saltwater exposure to reduce buildup of microorganisms and salt that degrade the membrane seal. Air-dry away from direct heat or sunlight; membrane damage from heat accelerates any leaching risk. Replace when outsole tread flattens or upper separates from sole (typically 300-500 miles). Do not machine wash, bleach, or use heat sources, as these can compromise the GTX laminate and increase micro-tear risk. If waterproofing fails, the shoe becomes a standard mesh runner.
What is not known about PFAS in this product?
- Basis
- Model estimate, 45% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- HOKA has made none
Formulations change between production runs, so check the current label. How we grade.
What are the PFAS-free alternatives to Hoka Men's Clifton 9 GTX?
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4 hazards checked on this product, all on its full breakdown.
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- Mesh upper, Fresh Foam midsole, rubber outsole
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- Azo dyes and color-based toxins
2 hazards checked on this product, all on its full breakdown.
Find an alternative on AmazonMore running & athletic shoes grades
How we score, every product runs through the same public 0-100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.