Sports Performance Undergarments, ranked by PFAS safety

15 products graded from Bad to Excellent, safest first. None grade Good or better yet, so we show the full ranking and the least-concerning options first.

By material:Wool

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The best non-toxic sports performance undergarments, ranked safest first

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Graded and flagged Poor and Bad, we’d swap these

Feetures High Performance Cushion No Show Tab

Feetures

High Performance Cushion No Show Tab

Acrylic blend sock with no disclosed treatments

PFAS Grade65Good
Good

Lower concern; no water-repellent coating treatment disclosed for socks.

Risky category by default

Feetures Elite Light Cushion Tab Limited Edition Performance Socks

Feetures

Elite Light Cushion Tab Limited Edition Performance Socks

Merino wool blend, nylon, elastane

PFAS Grade65Good
Good

Lower concern. Merino wool socks unlikely to contain PFAS, but brand offers no transparency.

Risky category by default

Feetures High Performance Max Cushion Tab Socks

Feetures

High Performance Max Cushion Tab Socks

Merino wool blend, synthetic fibers

PFAS Grade65Good
Good

Lower concern socks; no PFAS-prone features identified.

Risky category by default

Smartwool Men's Run Targeted Cushion Mid Crew Socks

Smartwool

Men's Run Targeted Cushion Mid Crew Socks

Merino wool blend with synthetic nylon reinforcement

PFAS Grade65Good
Good

Lower concern. Natural fiber socks unlikely to contain PFAS.

Risky category by default

Smartwool Run Pattern Crew Socks 3-Pack

Smartwool

Run Pattern Crew Socks 3-Pack

Merino wool blend, no water repellent finish

PFAS Grade65Good
Good

Lower concern. Merino wool socks with no waterproof coating.

Risky category by default

Smartwool Women's Run Targeted Cushion Low Ankle Socks

Smartwool

Women's Run Targeted Cushion Low Ankle Socks

Merino wool blend, no specified water-repellent coating treatment

PFAS Grade65Good
Good

Lower concern. Merino wool socks without disclosed water repellent treatment.

Risky category by default

Smartwool Unisex Run Zero Cushion Crew Socks

Smartwool

Unisex Run Zero Cushion Crew Socks

Merino wool blend, no stated water-repellent treatment

PFAS Grade65Good
Good

Lower concern. Merino wool socks lack typical water-repellent coating coatings.

Risky category by default

Smartwool Men's Run Zero Cushion No Show Socks

Smartwool

Men's Run Zero Cushion No Show Socks

Merino wool blend, no reported water-resistant treatment

PFAS Grade65Good
Good

Lower concern. Merino wool socks unlikely to contain intentional PFAS.

Risky category by default

PUMA Men's 6 Pack 1/2 Terry Socks

Puma

Men's 6 Pack 1/2 Terry Socks

Cotton blend terry cloth

PFAS Grade65Good
Overall Grade57Good
⚠️

Antimony in polyester

Limited concern

70
🫧

Microplastics

Limited concern

70

Lower concern. Basic socks with no known PFAS-prone treatments.

Risky category by default

PUMA Men's DryCell Crew Socks (8 Pair)

Puma

Men's DryCell Crew Socks (8 Pair)

Cotton/polyester blend, DryCell moisture-wicking treatment

PFAS Grade65Good
Overall Grade53Good
🎨

Azo dyes and colorfast stability

Limited concern

70
⚠️

Antimony in polyester

Limited concern

70
🎨

Dye migration and skin irritation

Limited concern

70

Lower concern socks. No known PFAS risk in standard construction.

Risky category by default

PUMA Women's Quarter Crew Socks (6 Pairs)

Puma

Women's Quarter Crew Socks (6 Pairs)

Cotton/polyester blend socks, no waterproofing

PFAS Grade65Good
Overall Grade47Poor
🎨

Azo dyes

Limited concern

70
💨

Formaldehyde / VOCs

Limited concern

70
🫧

Microplastic shedding

Moderate concern

45

Lower PFAS concern; basic untreated socks without water resistance.

Risky category by default

PUMA Men's Dry Cell Moisture Wicking Socks

Puma

Men's Dry Cell Moisture Wicking Socks

polyester and elastane blend, moisture-wicking synthetic fibers

PFAS Grade65Good
Overall Grade53Good
🎨

Azo dyes in polyester

Limited concern

70

Elastane (spandex) degradation under heat or UV

Limited concern

70
🏷️

PFAS

Limited concern

70

Lower PFAS concern, but brand silent on water-repellent coating treatment used.

Risky category by default

PUMA Men's Half-Terry Crew Socks (3 Pairs)

Puma

Men's Half-Terry Crew Socks (3 Pairs)

Cotton/polyester blend, half-terry construction

PFAS Grade65Good
Overall Grade49Poor
🎨

Azo dyes and residual colorants

Limited concern

70
💨

Formaldehyde / VOCs

Limited concern

70

Elastic degradation and skin contact

Limited concern

70
🫧

Microfiber shedding

Limited concern

70

Lower concern. Basic socks unlikely to contain PFAS.

Risky category by default

Feetures High Performance Ultra Light No-Show Tab

Feetures

High Performance Ultra Light No-Show Tab

Nylon blend with moisture-wicking treatment

PFAS Grade20Bad
Bad

Moisture-wicking socks likely treated; brand silent on PFAS.

Waterproof or stain-proof treatment

Smartwool Men's Run Cold Weather Targeted Cushion Crew Socks

Smartwool

Men's Run Cold Weather Targeted Cushion Crew Socks

Merino wool with water-repellent coating finish

PFAS Grade20Bad
Bad

Merino wool is PFAS-risk material; water-repellent coating finish raises concern.

Waterproof or stain-proof treatment

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