Brooks · Running & Athletic Shoes
Brooks Men's Cascadia 20 GTX
GTX waterproofing likely uses PFAS; Brooks silent on PFAS risk.
Brooks Cascadia 20 GTX uses Gore-Tex, a waterproof membrane typically containing PFAS for water repellency. Brand makes no public PFAS disclosures or commitments.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Gore-Tex waterproof membrane with textile upper
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What Brooks Men's Cascadia 20 GTX is made of, ingredients and materials
The Cascadia 20 GTX uses Gore-Tex, a microporous Teflon-family coating membrane bonded to textile uppers, designed to shed water while allowing vapor escape. Gore-Tex waterproofing durability depends on fluorinated surfactants (PFAS) that degrade over time with washing and abrasion, releasing particles and chemicals into sweat and the environment. The textile upper is likely polyester or nylon with synthetic stitching; polyester can contain antimony (a trace catalyst) and both are dyed with azo dyes, which are regulated but require quality control to avoid banned carcinogenic variants.
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.
Teflon-family coating (Teflon-type coating/Gore-Tex) membrane degradation
Gore-Tex membranes are durable but degrade with repeated washing, abrasion, and UV exposure, potentially releasing microfibers and residual PFAS into sweat and groundwater. Durability is typically 3-5 years of regular use.
Azo dyes in textile upper and lining
Polyester and nylon uppers are dyed with azo dyes; EU and most major brands have phased out carcinogenic variants (e.g., benzidine-based), but Brooks does not publicly certify dye safety standards for this model.
Antimony in polyester fabric
Polyester fibers can contain antimony (Sb) as a catalyst residue at trace levels (typically <0.1%). Dermal absorption is low, but sweat-mediated leaching from heavily worn footwear is not well-characterized.
Adhesive and glue off-gassing
Shoe construction uses polyurethane or polyurethane-based adhesives to bond the Gore-Tex layer to the upper; volatile organic compounds (VOCs) can off-gas during the break-in period, particularly in warm conditions. Typically resolves within weeks.
What’s reassuring
Formaldehyde / VOCs
Formaldehyde-based finishes (e.g., for wrinkle resistance) are uncommon in performance footwear uppers and are not a documented concern for this product class; no evidence of their use in Brooks Cascadia.
Source, ATSDR ↗How is this PFAS grade calculated?
The brand's record and disclosure
Brooks does not publicly disclose PFAS content or phase-out timelines for Gore-Tex products, despite growing industry pressure. The company has no known third-party PFAS certifications (such as BlueSign or GOTS equivalents for footwear) and has not published a PFAS reduction roadmap. This silence is typical among mainstream footwear makers but limits transparency compared to outdoor brands (e.g., Patagonia) that have committed to alternatives with lower concern for PFAS.
How it compares in its category
Most high-performance hiking shoes at this price point (USD 150-180) use Gore-Tex or similar Teflon-type coating-based membranes; alternatives with non-fluorinated waterproofing (e.g., eVent, Pertex) exist but are rarer and often pricier. Brooks' construction quality and fit are competitive, but the trade-off is that you absorb the PFAS exposure burden without visibility into the brand's mitigation strategy. Budget or synthetic-only hiking shoes sidestep Gore-Tex but typically sacrifice durability and breathability.
If you buy it
Wash infrequently (after heavy mud or salt exposure) using cool water and air-dry to preserve membrane integrity and reduce leaching. Do not machine wash or dry-clean; hand wash with mild detergent if needed. Replace when the sole shows significant wear, the upper develops tears, or the waterproofing noticeably degrades (usually 300-500 miles of hiking). Store in a cool, dry place away from direct heat to slow Teflon-family coating breakdown.
What is not known about PFAS in this product?
- Basis
- Model estimate, 55% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Brooks has made none
Formulations change between production runs, so check the current label. How we grade.
What are the PFAS-free alternatives to Brooks Men's Cascadia 20 GTX?
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Find an alternative on Amazon
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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.