Men's Run Micro Crew Ultra-Lightweight Running Socks vs 4-Pack Everyday Athletic Crew Socks: which is safer?

Darn Tough Men's Run Micro Crew Ultra-Lightweight Running Socks is our pick: better on PFAS and on the overall hazard picture.

Our pick

Darn Tough Men's Run Micro Crew Ultra-Lightweight Running Socks

Darn Tough

Men's Run Micro Crew Ultra-Lightweight Running Socks

PFAS grade

Good 65/100

Overall grade

Good 57/100

Verdict

Skip

Hazard flags

⚑ 2

Material

Merino wool blend, synthetic fibers (nylon/spandex)

Confidence

72%

PossibleAntimony in synthetic fibers

PossibleMicroplastic shedding during wash

Smartwool 4-Pack Everyday Athletic Crew Socks

Smartwool

4-Pack Everyday Athletic Crew Socks

PFAS grade

Good 65/100

Overall grade

Good 53/100

Verdict

Skip

Hazard flags

⚑ 3

Material

merino wool blend (primary fiber)

Confidence

72%

PossibleAzo dyes (aniline-derived synthetic colorants)

PossibleElastane (spandex) degradation and skin contact

PossibleDurable-water-repellent (water-repellent coating) coating composition

Where these two actually differ

  • We flag Antimony in synthetic fibers and Microplastic shedding during wash on the Darn Tough and not on the Smartwool.
  • We flag Azo dyes (aniline-derived synthetic colorants), Elastane (spandex) degradation and skin contact and Durable-water-repellent (DWR) coating composition on the Smartwool and not on the Darn Tough.
  • The Darn Tough is Merino wool blend, synthetic fibers (nylon/spandex) where the Smartwool is merino wool blend (primary fiber), which is most of the difference in these two grades.
  • These two are level, close enough that price and fit should decide it rather than our grade.

Both products run through the same public rubric: materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →

More performance socks: see the full ranking