Kotex · Incontinence Pads & Protection
U by Kotex Security Lightdays Liners
Skip. Waterproof menstrual products commonly use PFAS-based coatings.
U by Kotex does not disclose PFAS in liners. Waterproof backing in period products often contains legacy PFAS treatments; no lab testing or PFAS-free certification found on this product.
The safe swap
Tranquility
Tranquility Personal Care Pads 13.5" x 6.5", 96/Case
70/100 safety
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
absorbent core, adhesive layers, waterproof backing
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
period care 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
U by Kotex Lightdays liners use a three-layer structure: a top absorbent layer (typically wood pulp and superabsorbent polymer like sodium polyacrylate), a middle adhesive layer, and a waterproof backing. The waterproof backing is the material most likely to contain PFAS (per-and polyfluoroalkyl substances) used to repel fluids. Absorbent polymers and adhesives in this category are generally regarded as safe during short-term skin contact when intact, though continuous exposure to the genital microbiome warrants caution with any synthetic materials.
The brand's record and disclosure
Kotex (Kimberly-Clark) has not publicly disclosed PFAS content or committed to phase-out timelines for menstrual products, though the company has made PFAS commitments in other product lines (e.g., diapers). No recalls or safety violations specific to this product are on record. The brand does not advertise organic, hypoallergenic, or PFAS-free claims for Lightdays, positioning it as a mainstream, cost-accessible option rather than a premium safety-focused product.
How it compares in its category
Lightdays liners are typical conventional menstrual products and face the same PFAS waterproofing issue as most mass-market alternatives (Tampax, Always, Kotex mainline). Organic/PFAS-aware brands (Cora, Rael, Seventh Generation Free & Clear) have publicly committed to PFAS avoidance but at higher cost. Lightdays occupies the budget-friendly, high-availability tier where PFAS use remains standard industry practice.
If you buy it
Use as intended for light flow during daytime or overnight wear; do not heat, microwave, or compost. Replace every 4-6 hours or when saturated to prevent bacterial overgrowth in the warm, moist environment of the vulva, which is the highest-risk use scenario for any menstrual product. If you experience persistent irritation, odor, or discharge changes, discontinue and consult a healthcare provider. Consider rotating with alternative brands annually to reduce cumulative PFAS exposure if cost permits.
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 waterproof backing
Waterproof layers in conventional menstrual liners almost universally use PFAS-based coatings to prevent leakage. These compounds persist in the body and environment; Kotex has not disclosed specific chemistry or phase-out plans for this product line.
Superabsorbent polymer (SAP) gel integrity and skin contact
Sodium polyacrylate in the absorbent core can create microscopic gel particles if the layer breaches or degrades with friction. Direct vulvar contact with raw SAP particles is rare but could trigger irritation in sensitive users. No recalls for this product are documented.
Adhesive residue on skin
The adhesive layer may leave residue on vulvar skin if removed abruptly or worn for extended periods, particularly in warm/humid conditions. This is a contact irritant risk rather than a systemic toxicity issue, most relevant for users with sensitive skin or adhesive allergies.
Bacterial overgrowth risk from moisture retention
All conventional menstrual liners, including Lightdays, create an occlusive, warm environment that can promote bacterial overgrowth if worn too long. This is a use-scenario hazard (extended wear time) rather than a product defect, but relevant to practical safety.
Fragrance or dye additives (not confirmed for Lightdays)
Lightdays Liners are unscented and use minimal visible dyes. No documented sensitizer reports specific to this product. Bleached wood pulp may contain trace chlorine residues, but exposure is minimal and occurs at background levels in mainstream products.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 45% 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 Incontinence Pads & Protection
Tranquility
Personal Care Pads 13.5" x 6.5", 96/Case
Cellulose, wood pulp, absorbent core, adhesives
Lower PFAS concern. Typical absorbent pad with no known treatment.
⚠Risky category by default
Tranquility
Essential Booster Pads Heavy Absorbency, Long - 4-1/4 x 15 Inch (Case of 200)
cellulose/fluff pulp absorbent core with nonwoven layers
Lower concern. Core materials inherently PFAS-free, no evidence of water-repellent coating treatment.
⚠Risky category by default
Kotex
Absorbent Wrapped Liners
Cellulose-based absorbent core, wrapped nonwoven
Lower concern. No known PFAS use in standard absorbent liners.
⚠Risky category by default
More incontinence pads & protection 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.