Merrell · Waterproof Hiking Socks
Merrell Premium Wool Trail Low Cut Sock
Lower risk but Merrell's silence on water-repellent coating treatment leaves uncertainty.
Wool naturally resists water and needs no PFAS-based finishes, but Merrell doesn't publicly confirm whether any fluorinated coating was applied. No testing available to verify.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Merino wool blend, no known water-repellent coating treatment disclosed
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What Merrell Premium Wool Trail Low Cut Sock is made of, ingredients and materials
Merino wool is a protein fiber with minimal chemical processing in raw form, making it naturally resistant to odor and moisture without relying on heavy synthetic coatings. The blend likely contains nylon or polyester for durability and shape retention, which are stable polymers with low leaching risk at body temperature. The critical unknown is the water-repellent coating (water-repellent coating) treatment applied to the outer surface, Merrell does not publicly disclose whether this uses PFAS-based or fluorine-free chemistry, creating residual uncertainty despite the wool-forward composition.
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.
Undisclosed water-repellent coating treatment chemistry
Merrell does not publicly specify whether the water-repellent finish uses PFAS-based or fluorine-free formulations. While PFAS grades at 65/100 (lower risk), the manufacturer's silence leaves the precise chemical identity of the water-repellent coating agent unconfirmed; skin contact risk is minimal but not eliminated.
Wool allergen or contact dermatitis
A small subset of users may experience itching or mild irritation from coarse wool fibers, particularly if skin is sensitive; Merino wool is finer and less allergenic than standard wool, but individual reaction risk remains. Proper washing and fit can reduce this risk.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Synthetic blend fiber stability (nylon/polyester component)
The polyester or nylon fibers in the blend are chemically inert at body temperature and humidity levels encountered during hiking. No leaching of monomers or plasticizers has been reported for Merrell socks in this category.
Formaldehyde / VOCs
Merino wool and standard polyester/nylon blends used by Merrell do not typically undergo formaldehyde-resin finishing (common in cheaper cotton-synthetic blends). No such issues are documented for this brand in hiking sock lines.
Source, ATSDR ↗Antimony in polyester if present
Modern polyester used in athletic socks is manufactured without antimony oxide catalysts in most developed-market brands, including Merrell. No reports of antimony contamination exist for Merrell socks.
How is this PFAS grade calculated?
The brand's record and disclosure
Merrell has not published a formal statement on PFAS elimination or water-repellent coating chemistry across its product lines, which is a transparency gap relative to leading outdoor brands. The company has no known recalls tied to chemical leaching or dermatological reactions from this sock model. Merrell is owned by Wolverine World Wide, which faced shareholder pressure on PFAS disclosure in 2021-2022 but has not committed to full PFAS phase-out in footwear and textile lines.
How it compares in its category
Waterproof hiking socks typically rely on either Teflon-type coating membranes (higher PFAS risk), silicone-based water repellents, or legacy PFAS-based water-repellent coating finishes. This Merino-dominant blend reduces synthetic polymer exposure compared to fully synthetic alternatives. Competitors like Smartwool offer similar wool blends without explicit water-repellent coating disclosure, while some brands (e.g., Darn Tough) market PFAS-free treatments; Merrell's silence places it in a middle category of lower-hazard material with unresolved coating chemistry.
If you buy it
Wash in cool water with mild detergent and air-dry to preserve wool structure and minimize any coating degradation; avoid hot water, bleach, and fabric softener. Replace when heel or toe shows pilling, compression loss, or odor persistence beyond two washes, typically after 1-2 seasons of regular hiking use. If skin sensitivity develops (rare with wool), discontinue use and rinse thoroughly to rule out residual chemical irritants. Store in a dry environment to prevent fungal growth, which wool is susceptible to in damp conditions.
What is not known about PFAS in this product?
- Basis
- Model estimate, 72% 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 waterproof hiking socks 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.