Cups & Co · Period Underwear
The High Waisted Period. in Sporty Stretch For Heavy Flows
Lower PFAS concern for a period-care textile, but brand transparency is minimal.
Period underwear like Cups & Co's typically use cotton/elastic blends without the Teflon-family coating coatings common in water-resistant apparel. The main PFAS risk would be in waterproofing treatments or synthetic elastics (spandex), neither of which appears prominently marketed here.
Shop Cups & Co on Amazon →Material
Elastic/cotton blend with synthetic stretch (likely spandex or polyurethane)
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Category baseline
period care is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
The full breakdown
What it's made of and why it matters
This product combines cotton (absorbent, breathable base) with synthetic stretch fibers, most likely spandex (elastane) or polyurethane, to achieve the fitted, flexible fit needed for heavy-flow containment. The stretch component is crucial for comfort but introduces synthetic polymer chemistry that can leach plasticizers or residual monomers, especially under body heat and moisture. Cotton itself is a lower-risk fiber, but the dyes and finishing agents applied during manufacturing carry the primary concern for this product type.
The brand's record and disclosure
Cups & Co maintains a silent stance on PFAS and other chemical disclosures; no publicly available certifications (OEKO-TEX, GOTS, or similar) have been documented for this product line. The brand has not published manufacturing specifications, dye sources, or elastane treatment protocols. Without transparency reports or third-party testing claims, it is impossible to verify whether azo dyes, formaldehyde resins, or antimony catalysts were used in production. This opacity is typical of emerging period-care brands but represents a material information gap for informed purchasing.
How it compares in its category
Period underwear in the comfort-stretch category often relies on elastane and polyurethane blends; Cups & Co's formulation is standard for the segment. Certified competitors (e.g., those holding OEKO-TEX certification) offer documented chemical controls; this product does not. The cotton-blend approach is preferable to fully synthetic alternatives, but lack of brand transparency places it in the middle-to-lower confidence tier within its category. Most established period-care brands now disclose at least dye sources or antimicrobial treatments; Cups & Co's silence suggests either standard practices or reluctance to communicate.
If you buy it
Wash in cool to warm water before first use to remove excess dyes and finishes. Avoid heat (hot water, dryer, direct sunlight) as it can accelerate elastane breakdown and any residual monomer leaching. Replace after 1-2 years of regular use or when elastic loses tension, as degraded fibers are more likely to shed microplastics. Store in a cool, dry place away from direct heat; do not bleach or use fabric softeners, which can deposit additional chemicals and reduce absorbency.
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 reactive dye residues
Cotton-blend textiles are routinely dyed with azo or reactive dyes; Cups & Co provides no dye sourcing disclosure. Incomplete fixation can leave unreacted dye molecules that transfer to skin, particularly in the sensitive genital area during menstruation when pH and moisture levels are altered.
Elastane (spandex) monomer leaching
Polyurethane and elastane fibers can release residual monomers (e.g., toluene diisocyanate, caprolactam) under body heat and moisture. Period underwear sits directly against skin for extended periods, creating conditions favoring leaching; extent depends on production standards and post-manufacturing washing, neither disclosed here.
Formaldehyde-based finish resins
Cotton-synthetic blends often receive formaldehyde-based resin finishes for wrinkle resistance, water repellency, or antimicrobial properties. Cups & Co does not disclose finishing agents. Skin contact with residual formaldehyde can trigger contact dermatitis, particularly in individuals with sensitivities.
Antimony catalysts in polyester/elastane synthesis
If the synthetic stretch component is polyester-based elastane (less common in underwear but possible), antimony oxide catalysts used in fiber production could leave trace residues. This is not typical for elastane-dominant blends but cannot be ruled out without material specifications.
Microplastic shedding from degraded elastane
Over time and with repeated washing, elastane fibers degrade and can shed microplastic particles. This is less of a direct skin hazard than an environmental concern, but accumulated microplastics in washing may be ingested via drinking water or food. Expected lifespan is 1-2 years before significant degradation.
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.
Safer alternatives in Period Underwear
JAMA Organic
LOLA Organic Cotton Period Underwear
Organic cotton with moisture-wicking gusset
Lower PFAS concern, organic cotton base with no waterproof claims, but brand doesn't explicitly address PFAS.
✓Verified PFAS-free by a third party
JAMA Organic
Organyc Certified Organic Cotton Disposable Period Underwear for Sensitive Skin
certified organic cotton with absorbent core
Lower concern, organic cotton base suggests minimal PFAS risk, but no explicit PFAS statement limits confidence.
✓Verified PFAS-free by a third party
Ruby Love
Women's Hipster Period Underwear
organic cotton with waterproof coating
Lower concern, PFAS-free verified; buy with confidence.
✓Lab test found no PFAS
More period underwear 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.