Lululemon · Waterproof Sports & Performance Undergarments
UnderEase Mid-Rise Bikini Underwear 3-Pack
Lower concern. No PFAS-prone features identified in standard underwear.
Lululemon does not disclose PFAS treatment for this bikini. Nylon-elastane blend is not inherently linked to PFAS unless treated for water or stain resistance, which is uncommon for basic underwear.
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Material
Nylon blend with elastane
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
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
UnderEase uses a nylon and elastane (spandex) blend, common in performance intimatewear because nylon resists moisture, dries quickly, and elastane provides stretch recovery. Nylon itself is a thermoplastic polyamide with low leaching risk at body temperature and in contact with skin. Elastane is inert when properly manufactured. The concern lies in chemical residues from dyeing, finishing treatments, and elastane processing rather than the base polymers.
The brand's record and disclosure
Lululemon does not publish detailed chemical disclosures or certifications (e.g., GOTS, bluesign) for basic intimatewear lines. The brand has faced no major recalls or documented chemical safety violations for underwear products. Lululemon's silence on PFAS treatment and dye/finish protocols is typical for this market segment but represents a gap in transparency compared to leading sustainable apparel brands.
How it compares in its category
Mid-rise nylon-elastane bikinis are the industry standard and carry lower intrinsic risk than lycra-heavy high-compression garments or those with applied coatings. Lululemon's price point and brand positioning place it above mass-market equivalents (which often have identical fiber composition but less QC), though below certified organic cotton or bluesign alternatives. No published data suggests this product differs chemically from unnamed competitors in the same category.
If you buy it
Wash new garments separately in cool water before wearing to remove loose dye and finish residues. Use mild detergent; avoid fabric softeners, which can degrade elastane. Air-dry; heat from dryers accelerates elastane degradation and has no safety benefit here. Replace every 1-2 years when elastic loses recovery, as worn-out elastane may shed microfibers more readily. No special storage needed beyond normal underwear care.
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.”
Azo dyes and dye residues
Nylon takes color readily and Lululemon does not disclose dye chemistry. Poorly fixed azo dyes can release aromatic amines on skin contact or during washing, though regulated suppliers typically avoid banned azo dyes. Pre-wash reduces loose dye transfer.
Formaldehyde resins in finishing
Nylon fabrics are sometimes treated with formaldehyde-based resins for wrinkle resistance or shape retention. Lululemon does not specify finish type for this product. Off-gassing is minimal in finished garments worn on skin, but presence cannot be ruled out without testing.
Elastane (spandex) degradation and microfiber shedding
Elastane fibers naturally degrade under heat, UV, chlorine, and repeated laundering. Worn-out elastane sheds microplastics into water and accumulates on skin. This is not unique to Lululemon but inherent to elastane garments; normal replacement cycle (1-2 years) minimizes exposure.
Antimony in polyester components (if present)
UnderEase is nylon-elastane, not polyester, so antimony catalyst use is unlikely. Nylon polymerization does not rely on antimony. No concern for this product.
Heavy metals in dyes or pigments
Black and dark nylon underwear may contain trace chromium, copper, or nickel from dye chemistry, though regulated manufacturers keep levels below skin-contact thresholds. Lululemon does not publish heavy metal test results; compliance is assumed but unverified.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% 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 & performance 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.