Lowa · Hiking Shoes & Trail Runners
Lowa Men's Zephyr MK2 GTX Mid Boots
Hiking boots with Gore-Tex waterproofing; likely PFAS-treated, brand silent.
Lowa does not disclose PFAS use or sourcing. Gore-Tex lining typically contains PFAS Teflon-family coating for waterproofing, though Lowa provides no transparency on treatment chemicals.
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Material
Leather, nubuck upper; Gore-Tex lining; rubber sole
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Waterproof / stain-resistant treatment
water-repellent coating treatments have historically used PFAS.
Category baseline
clothing is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
The full breakdown
What it's made of and why it matters
The Zephyr MK2 GTX combines nubuck leather (suede-finished) upper with Gore-Tex laminate lining for waterproofing. Nubuck is leather treated with fine abrasion to create a velvet-like pile, which increases surface area for potential chemical absorption and dust generation. The Gore-Tex layer itself is a Teflon-type coating-based membrane, and the waterproofing treatment on both leather and Gore-Tex typically involves fluorinated compounds (PFAS), though Lowa has not publicly disclosed their specific chemistry.
The brand's record and disclosure
Lowa is a German heritage outdoor footwear maker with no published PFAS phase-out commitment or transparent chemical disclosure policy on their website. The brand has not engaged in major safety controversies on record, but their silence on PFAS and dye/finish chemistry in leather products is typical of the mid-premium hiking boot segment. No third-party certifications (bluesign, OEKO-TEX) are advertised for this model.
How it compares in its category
Lowa Zephyr boots occupy the quality-focused middle tier of hiking footwear; they are more transparent than budget brands but less so than premium PFAS-conscious makers like Salomon (who disclose some PFAS reduction efforts). Most Gore-Tex hiking boots in this price range use untested PFAS-based waterproofing. Competitors like Salewa and Arc'teryx similarly avoid public PFAS disclosure.
If you buy it
Clean nubuck regularly with a dry brush to minimize dust inhalation from the treated pile surface. Avoid machine washing or soaking; spot-clean with minimal water and air-dry away from direct heat. Replace insoles if they develop odor or breakdown (usually 1-2 seasons of heavy use) to prevent bacterial growth in a moist microenvironment. Gore-Tex lining typically remains effective for 3-5 years with proper drying between uses; once waterproofing fails, the boot's lifespan is effectively over for serious hiking.
Beyond PFAS: other things we checked
Established hazard classes for this product type, assessed from public information. These never change the PFAS grade; a Likely flag caps the Verdict at “Buy with care.”
Azo dyes in leather and nubuck finish
Nubuck upper is dyed leather; standard vegetable-tanned or chrome-tanned leather used in outdoor footwear often employs azo dyes. These can degrade to release aromatic amines under sweat and friction, though exposure in a sealed boot is lower than in direct-contact apparel. Lowa does not publish dye specifications.
Formaldehyde resins in leather treatment and finish
Leather finishing and waterproofing treatments may include formaldehyde-releasing compounds for water resistance and durability. No off-gassing testing is available for this specific model; initial odor in new boots may indicate residual finish chemistry.
Chromium and heavy metals in leather tanning
If chrome-tanned (most likely for this price tier), leather contains bound chromium(III). Migration into skin during wear is minimal in a sealed boot, but leather dust or degradation over years could present a low-level exposure pathway. Tanning method is not disclosed.
Microplastic shedding from synthetic Gore-Tex liner
Gore-Tex membrane itself is Teflon-type coating (Teflon-family coating), not a source of microplastics in the traditional sense. However, any synthetic adhesives or backing layers could degrade over time; no documented shedding issue is on record for Gore-Tex boots.
Bacterial or fungal growth in Gore-Tex lining if not dried
The laminated lining traps moisture if boots are not dried properly after wet use. Extended damp storage creates risk of mold, which can trigger respiratory irritation or allergic response, particularly in users with sensitivity. This is a use-maintenance issue rather than a design defect.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 62% confidence. It is not a lab result.
No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.
The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.
Formulations and coatings change between production runs. Always check the current label before buying.
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.