Nike · Waterproof Sports Undergarments
Nike Women's Swift Breathe Dri-FIT Running Tank Top
Athletic tank with likely water-repellent coating finish; Nike silent on PFAS content.
Nike's Dri-FIT technology typically uses moisture-wicking coatings, often fluorinated, but Nike discloses nothing publicly about PFAS. No third-party testing available for this specific product.
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Material
Polyester blend with Dri-FIT moisture-wicking finish
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Waterproof / stain-resistant treatment
water-repellent coating treatments have historically used PFAS.
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
This tank is primarily polyester blended with elastane (spandex), topped with Nike's proprietary Dri-FIT moisture-wicking finish. Polyester itself is chemically stable when worn, but the performance coatings applied to athletic textiles to repel sweat and water are where chemical concerns arise. The Dri-FIT treatment almost certainly involves a water-repellent (water-repellent coating) finish, which historically has relied on PFAS compounds, though Nike has not publicly disclosed whether they have transitioned to PFAS-free alternatives for this line.
The brand's record and disclosure
Nike signed the Bluesign System partnership in 2015 and has committed to phasing PFAS in some product lines, but has not published a comprehensive PFAS elimination timeline or third-party verification of compliance for apparel. The brand remains largely silent on the chemical composition of Dri-FIT treatments across their range. Unlike some competitors (Patagonia, Arc'teryx), Nike does not provide detailed chemical disclosure or independent audit reports on textile finishes, making assessment of this specific tank's PFAS content impossible without direct testing.
How it compares in its category
Women's running tanks occupy a middle ground in chemical risk: less problematic than heavily treated outdoor gear (which uses heavy-duty water-repellent coating), but more chemically processed than basic cotton basics. Nike tanks are mainstream and widely worn; independent testing by Safer Chemicals Healthy Families and others has flagged PFAS in Nike apparel, though not all products test positive. Brands explicitly marketing PFAS-free performance wear (Allbirds, some Patagonia lines) offer lower-risk alternatives if PFAS is a priority concern.
If you buy it
Wash in cold water before first wear to reduce any loose surface treatments. Machine wash on gentle, warm or cold, and air dry to minimize degradation of the Dri-FIT coating. There is no heat threshold concern as with cookware, but repeated washing will gradually reduce the moisture-wicking performance; replacement is typical after 50-100 washes depending on intensity of use. If PFAS exposure is a priority, request Nike's Material Safety Data Sheet for this specific SKU, or opt for brands with published PFAS-free commitments.
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.”
PFAS in water-repellent coating finish
Polyester athletic wear with Dri-FIT moisture-wicking treatment highly likely contains fluorinated compounds; Nike has not disclosed PFAS status for this product line and third-party testing has detected PFAS in Nike apparel.
Azo dyes
No specific azo dye violations recorded for Nike women's apparel. Polyester blends routinely use synthetic dyes, but regulated brands like Nike typically screen for banned azo compounds per REACH/ZDHC standards.
Formaldehyde resins (durable-press finishes)
Dri-FIT is a physical moisture-management fiber blend rather than a formaldehyde-based resin finish, so formaldehyde risk from resins is not a primary concern for this product type.
Antimony in polyester
Polyester is often synthesized using antimony trioxide as a catalyst; residual antimony can remain in finished fabric at low levels. Nike apparel has not been documented with elevated antimony, but the risk is inherent to polyester production unless explicitly certified antimony-free.
Microfiber shedding during wash
Synthetic athletic wear sheds microplastics in the washing machine; polyester-elastane blends shed at higher rates than 100% natural fibers. This is an environmental concern rather than direct health hazard to the wearer, but noted for lifecycle awareness.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 62% 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 waterproof sports 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.