All 15 sports performance undergarments we scored fail our PFAS screen

We scored 15 sports performance undergarments for PFAS forever chemicals and other hazards, then ranked them safest first. Every score below links to the full breakdown of what earned it.

How to read these scores. PFAS Authority is a scoring system, not a laboratory. We do not test products ourselves. Each grade is a model-based assessment built from published ingredient lists, materials, certifications, brand disclosures, recalls and third-party lab results where they exist. Read the full rubric to see exactly what adds and removes points.
100% of the 15 sports performance undergarments we scored fail our PFAS and toxin screen.
PFAS Authority, September 2026. Free to cite with a link. See the full dataset.

The safest PFAS-free sports performance undergarments we have scored

Nothing in this category clears our buy threshold yet. That is the finding, not a gap.

The sports performance undergarments we would skip

Lowest scoring in this category, worst first.

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

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

What we check on sports performance undergarments

  • Confirmed PFAS, PTFE or fluoropolymer content, which is the heaviest penalty we apply.
  • Stain, water or grease resistant treatments, which usually mean fluorinated chemistry.
  • Whether the brand discloses what is in the product, or stays silent behind a “clean” claim.
  • Independent lab results and certifications where they exist.

Full point-by-point rubric on the methodology page.

The sports performance undergarments brands that will not say

3 of the brands here publish nothing about PFAS at all. Silence is not evidence of harm, but it is why none of them score well on disclosure.

Feetures, Puma, Smartwool.

Common questions about PFAS-free sports performance undergarments

Is sports performance undergarments PFAS free?

Mostly not. Of the 15 sports performance undergarments we have scored, 100% fail our PFAS and toxin screen, which leaves 0 that pass. The lowest is Feetures Feetures High Performance Ultra Light No-Show Tab at 20.

Which sports performance undergarments should I avoid?

The three lowest scoring we hold are Feetures Feetures High Performance Ultra Light No-Show Tab at 20, Smartwool Smartwool Men's Run Cold Weather Targeted Cushion Crew Socks at 20, Feetures Feetures High Performance Cushion No Show Tab at 65. The problem with the first is that moisture-wicking socks likely treated; brand silent on PFAS.

Which sports performance undergarments brands will not say whether they use PFAS?

3 of the brands we scored in this category publish nothing about PFAS at all, including Feetures, Puma, Smartwool. Silence is not evidence of harm, but it is the reason those brands cannot score well on disclosure.

Do you lab test sports performance undergarments?

No. We score from published ingredient lists, materials, certifications, disclosures and third party lab results where they exist. Where a product has been independently tested we use that result and say so.

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Want to filter the whole category yourself? Browse all 15 sports performance undergarments.