Injinji · Sports Performance Undergarments
Injinji Trail Midweight Crew
Lower concern; untreated merino wool socks unlikely to contain PFAS.
Injinji Trail Midweight Crew are merino wool blend socks with no disclosed water repellent or stain treatment. Untreated natural fiber carries lower PFAS risk, though brand provides no PFAS disclosure.
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Material
merino wool blend, no water treatment specified
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
Injinji Trail Midweight Crew socks are a merino wool blend, typically mixed with synthetic fibers (often nylon or polyester) for durability and shape retention. Merino wool itself is a natural protein fiber with minimal processing risk for hazardous residues compared to synthetics. The synthetic portion introduces polyester, which can contain trace antimony (a flame retardant catalyst) but at levels not regulated in apparel. No water treatment or antimicrobial finish is specified for this product, which actually reduces exposure to problematic chemical coatings.
The brand's record and disclosure
Injinji does not publicly disclose detailed chemical or PFAS testing for their sock lines; the company maintains minimal transparency on material certifications and manufacturing. No major recalls or documented chemical hazard complaints are on record for their socks. The brand does not claim organic, GOTS (Global Organic Textile Standard), or other third-party chemical certifications, meaning buyers have limited independent verification of processing standards.
How it compares in its category
Merino wool blend socks are considered lower-risk compared to synthetic-only athletic socks or heavily treated performance textiles. Untreated merino wool avoids formaldehyde resin finishing and reduces azo dye exposure versus cheaper synthetic alternatives. However, they are less transparent than certified organic wool blends (e.g., those with GOTS certification) and less traceable than brands that publicly test for PFAS and heavy metals in dyes.
If you buy it
Wash socks in cool to warm water before first wear to reduce loose dyes and finishing residues. Merino wool is resilient and typically lasts 1-2 years with proper care; replace when elastic fails or fiber pilling becomes excessive. Avoid high-heat drying, as sustained heat can degrade both wool and synthetic fibers. These socks do not require special storage and can be machine washed with standard detergent; no antimicrobial treatment means no need for special antifungal protocols.
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 and colorant residues
Merino wool and polyester blends are typically acid-dyed; unreacted dye molecules and heavy metals (lead, chromium) in pigments may remain in yarn if dyebath rinsing is incomplete. No testing data is publicly available for Injinji products.
Antimony in polyester
Polyester typically uses antimony oxide as a catalyst during manufacture. Trace antimony can migrate from synthetic fibers but exposure from skin contact with socks is negligible unless fabric is degraded or heavily abraded.
Formaldehyde finishing resins
No formaldehyde resin treatment is standard for merino wool blends or Injinji's disclosed process. Untreated merino wool socks carry minimal risk for formaldehyde residues.
Allergens from fragrance or antimicrobial additives
Injinji does not add fragrance or antimicrobial coatings to this product line based on available product information. No known sensitization complaints are documented.
Microfiber shedding and synthetic degradation
Repeated washing and friction can cause nylon/polyester fibers to shed microplastics into wastewater. This is a durability and environmental concern rather than a direct skin safety hazard, but relevant to informed consumption.
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 sports performance undergarments 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.