Darn Tough Review, Is Darn Tough Non-Toxic?
PFAS Authority is a scoring system, not a laboratory. We do not test products ourselves. Grades are model-based, built from published ingredients, materials, certifications, brand disclosures and third-party lab results where they exist. See the rubric.
Across 5 graded products, Darn Tough averages Good (65/100). On disclosure, the brand says nothing publicly about PFAS. None of its products grade Good or better yet. Grades are model-based estimates, not lab results.
Graded and flagged Poor and Bad, we’d swap these
Darn Tough
Men's Spaced Out Micro Crew Lightweight Hiking Socks
Merino wool blend, nylon, spandex
Lower PFAS concern for untreated wool socks.
⚠Risky category by default
Darn Tough
Men's Hiker Encounter 2-Pack
Merino wool blend, no water-repellent treatment applied
Lower PFAS concern. Wool hiking socks without water-repellent coating treatment are a safer choice.
⚠Risky category by default
Darn Tough
Men's Weird and Wild Hiking 2-Pack
merino wool blend, nylon
Lower concern. Natural-fiber hiking socks unlikely to require PFAS. No public disclosure from Darn Tough.
⚠Risky category by default
Darn Tough
Men's Run No Show Tab Ultra Lightweight
Merino wool blend
Formaldehyde / VOCs
Synthetic fiber components (nylon, polyester) in blended socks may carry…
Microfiber shedding (synthetic components)
The nylon or polyester blend component may shed microfibers during washing, contributing…
Lower concern since natural fiber socks unlikely to contain PFAS, but brand makes no transparency claim.
⚠Risky category by default
Darn Tough
Men's Run Micro Crew Ultra-Lightweight Running Socks
Merino wool blend, synthetic fibers (nylon/spandex)
Antimony in synthetic fibers
Nylon and spandex may contain trace antimony as a catalyst residue from polymerization…
Microplastic shedding during wash
Synthetic fibers (nylon/spandex) shed microfibers when laundered; this is inherent to the…
Lower PFAS concern for a basic athletic sock; no evidence of water-repellent coating or fluorochemical treatment.
⚠Risky category by default
Every grade uses the same public rubric. How grades work →