Merrell · Hiking Shoes & Trail Runners
Merrell Men's Moab Adventure 3 Waterproof
Unknown waterproof coating, Merrell doesn't disclose PFAS status.
Merrell applies waterproof treatment to this shoe but won't reveal PFAS chemistry details. Without lab testing or brand transparency, PFAS risk cannot be ruled out.
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Material
Synthetic leather/nubuck upper with water-repellent coating waterproof coating
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
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.
Waterproof / stain-resistant treatment
Water-repellent coating treatments have historically used PFAS.
Formaldehyde / VOCs
Synthetic leather and nubuck layers are often bonded using formaldehyde-based adhesives. Merrell does not disclose adhesive chemistry; typical footwear adhesives may off-gas minimally after manufacturing, but new boots may have detectable off-odor. Airing boots outdoors before first wear reduces exposure.
Source, ATSDR ↗Azo dyes in synthetic leather coloring
The dark colored synthetic upper likely contains azo dyes, which are standard in polyurethane footwear. Banned azo dyes that cleave to carcinogenic amines are prohibited in EU and most branded footwear, but Merrell does not certify compliance. Risk is low in finished product but non-zero for workers and consumers with sensitive skin.
water-repellent coating degradation and reapplication risk
Merrell's proprietary water-repellent coating will degrade with wear and washing, typically lasting 6-18 months. Users often reapply commercial water-repellent coating sprays, which may introduce different chemical profiles (sometimes fluorocarbon-based). No guidance is given on reapplication products with lower PFAS concern, creating a secondary exposure pathway.
PFAS
The water-repellent coating is the primary concern. While not PFAS-specific for this assessment, the undisclosed chemistry and industry-wide prevalence of PFAS in waterproof footwear coatings means risk cannot be ruled out. This is the largest integrity gap in Merrell's transparency for this product.
Source, ATSDR ↗What’s reassuring
Synthetic rubber sole toxicity
The outsole is synthetic rubber (likely EPDM or similar) and presents no established toxicological concern in finished form. Sole odor in new boots is typical off-gassing and dissipates quickly; no heavy metals or phthalates are standard in Merrell soles based on available information.
The full breakdown
What it's made of and why it matters
The Moab 3 uses a synthetic leather (likely polyurethane or PU) upper bonded to a nubuck overlay, treated with a water-repellent coating (water-repellent coating) finish. Synthetic leather avoids heavy metal risks found in some chrome-tanned genuine leathers, but the water-repellent coating chemistry is proprietary and not disclosed by Merrell. This coating is where PFAS or alternative water-repellent compounds reside, making transparency critical for this product class.
The brand's record and disclosure
Merrell, owned by Wolverine Worldwide, does not publicly disclose whether its water-repellent coating treatments contain PFAS or which alternatives (if any) it uses. The parent company has faced scrutiny over PFAS in outdoor footwear but has not issued product-specific commitments for the Moab line. Merrell provides care instructions but no material safety data sheets for consumers.
How it compares in its category
Most hiking boots at this price point use undisclosed water-repellent coating coatings; premium brands like Salomon and La Sportiva have begun offering PFAS-free options or transparency. The Moab 3 is competitively positioned but lags transparency-leading brands. Many alternatives use fluorocarbon-free or bio-based water repellents, though performance longevity claims vary.
If you buy it
Wash boots in cool water with mild soap; avoid machine washing or heat drying, which can degrade the water-repellent coating and potentially increase leaching risk. Reapply commercial water-repellent coating treatments attributed to brands as PFAS-free (like Nikwax) annually to maintain water resistance without adding unknown chemistry. Replace boots when structural integrity fails (sole separation, upper creasing that lets water through), not solely when water-repellent coating fades. Store in a cool, dry place away from direct heat or UV.
What we don’t know
- Basis
- Model estimate, 45% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Merrell has made none
Formulations change between production runs, so check the current label. How we grade.
More hiking shoes & trail runners 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.