Keen · Athletic Insoles & Orthotics
KEEN Men's Utility K-20 Cushion Insole
Lower concern; standard foam insole with no PFAS-typical features identified.
Keen utility insoles use foam cushioning without water-repellent or stain-resistant coatings that typically contain PFAS. No public PFAS disclosures or concerns found for this product line.
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Material
foam cushioning, likely polyurethane or EVA
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
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 K-20 Cushion Insole uses foam cushioning, most likely polyurethane (PU) or ethylene-vinyl acetate (EVA), both common in athletic footwear insoles. These foams are chosen for shock absorption and comfort but can off-gas volatile organic compounds (VOCs) during manufacturing and in the first weeks of use. Keen does not publicly disclose the specific foam formulation or presence of chemical softeners, flame retardants, or colorant additives in this insole. The insole is a replacement/upgrade component rather than the primary shoe, so skin contact is indirect and exposure duration is limited to wear-time only.
The brand's record and disclosure
Keen has published a sustainability commitment emphasizing reduction of hazardous chemicals and transparency, but insoles are not typically featured in their detailed chemical disclosure documents. The company does not appear to have faced major product safety recalls related to insoles or foam cushioning. However, Keen's publicly available information on flame retardants, colorants, and off-gassing mitigation for insole-specific materials is minimal. For a replacement insole product, the lack of specific material certification (e.g., Cradle to Cradle, bluesign) is typical but limits verification of VOC and additive control.
How it compares in its category
Replacement insoles from mainstream brands (Keen, Superfeet, Dr. Scholl's, Spenco) rarely carry third-party certifications or detailed chemical inventories. Most use either EVA or polyurethane foam with synthetic covers. Keen's K-20 sits in the mid-market comfort tier and does not stand out as unusually transparent or risky compared to competitors. Specialty insoles marketed as 'natural' or 'orthopedic' sometimes avoid PU/EVA but are rarer and more expensive; standard foam insoles like this are the industry norm.
If you buy it
Air the insoles in a well-ventilated space for 24-48 hours after unboxing to minimize VOC inhalation from new foam. Replace them every 12-18 months of regular use, as foam compression and breakdown increase risk of microparticle shedding and loss of cushioning. Do not wash in hot water or place in direct sunlight for extended periods, as heat can accelerate off-gassing and foam degradation. If you experience irritation, redness, or odor that persists beyond the first week, discontinue use and switch to an alternative brand.
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.”
VOC off-gassing from polyurethane or EVA foam
New foam insoles routinely off-gas volatile organic compounds during the first few weeks of use. No specific test data on the K-20 is publicly available, but this is a known characteristic of both PU and EVA foam cushioning materials. Off-gassing is typically strongest in sealed packaging and decreases with ventilation.
Flame retardants in foam or cover material
Keen does not publicly disclose whether flame retardants are used in the K-20 insole foam or synthetic cover. Replacement insoles are not regulated as apparel under flame-safety standards, so their use is not required, but independent confirmation would require direct laboratory testing or manufacturer disclosure.
Microplastic shedding from foam breakdown
As foam cushioning compresses and degrades over 12-18 months of use, it may shed microparticles into socks and eventually the environment. This is an inherent characteristic of foam-based insoles and is not specific to Keen, but replacement frequency and proper disposal can limit accumulation.
Azo dyes or other synthetic colorants in cover material
The insole cover is typically a synthetic textile or laminate; Keen does not publicly specify colorant type or whether azo dyes are present. Direct skin contact is minimal since insoles sit inside shoes, so risk from dermal exposure is low.
Allergen response to foam or adhesives
A small number of users may experience contact dermatitis or irritation from foam components, adhesives binding the layers, or residual manufacturing chemicals. No specific adverse-event data on the K-20 is on record, but such reactions are documented occasionally for replacement insoles in general.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% 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 athletic insoles & orthotics 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.