Coros · Water-Resistant Smart Rings & Bands
COROS Nylon Sailcloth Watch Bands Quick Release Strap Waterproof Sport
Skip; waterproof coating unspecified, likely water-repellent coating treatment.
This nylon watch band has waterproof treatment but no disclosed water-repellent coating technology. Brand provides no PFAS information; coating type remains unknown.
The better-graded swap
Even Realities
Even R1 Smart Ring
85/100 safety
Same rubric that flunked this product. The swap earned Excellent.
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Nylon with unspecified waterproof coating
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
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What COROS Nylon Sailcloth Watch Bands Quick is made of, ingredients and materials
This is a nylon textile (polyamide 6 or 6.6) with an undisclosed waterproof or water-resistant coating. Nylon itself is stable and inert during normal wear. The waterproofing is the hazard variable, it is almost certainly a water-repellent coating (water-repellent coating) treatment, which in the textile industry typically means Teflon-type coating-based or fluorocarbon-based polymers (PFAS). Without Coros publishing the coating chemistry, you cannot verify whether it is PFAS-free or whether it migrates to skin during sweating.
What’s concerning
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
Waterproof / stain-resistant treatment
Water-repellent coating treatments have historically used PFAS.
water-repellent coating (water-repellent coating) / Waterproof Coating Chemistry
Standard textile waterproofing is PFAS-based fluorocarbon. Coros does not publish coating type. Skin contact during daily wear is sustained but transdermal absorption from coated textiles is not quantified in literature. Migration risk increases with friction, sweat, and heat.
Formaldehyde / VOCs
Nylon fabric often undergoes anti-shrink or crease-resist finishing with formaldehyde condensation resins. Coros provides no OEKO-TEX or similar testing. Direct skin contact with untested nylon carries low but unquantified risk of off-gassing or residual formaldehyde, especially when new or heated.
Source, ATSDR ↗Coating Degradation and Microparticle Release
Nylon watch bands flex constantly at the wrist. Over time, waterproof coatings can crack, peel, or shed microparticles. Inhalation or skin contact with degraded coating particles is a minor but plausible long-term risk if the band is not maintained or replaced.
Allergic Contact Dermatitis from Undisclosed Additives
Nylon production involves plasticizers, flame retardants, and UV stabilizers. Without Coros material disclosure, exact additives are unknown. Daily skin contact poses cumulative risk for sensitized individuals, particularly if sweating increases contact time and permeability.
What’s reassuring
Azo Dyes and Colorant Safety
No specific dye incidents reported for Coros watch bands. Nylon readily accepts synthetic dyes; untested colorants may contain banned azo compounds (especially in imported goods). No third-party dye testing disclosed by Coros.
The full breakdown
The brand's record and disclosure
Coros is a sports-watch and accessory brand with no published chemical disclosure statements, sustainability certifications, or PFAS policies found in public record. The company does not appear to have addressed textile safety standards (Bluesign, GOTS, OEKO-TEX) for this product line. This silence on material sourcing and treatment chemistry is typical of smaller outdoor brands but represents a disclosure gap for consumers concerned about long-term skin contact with coated textiles.
How it compares in its category
Watch bands and straps occupy a gray zone, they are worn against skin daily (higher concern) but are not ingested or inhaled and do not retain water. Nylon watch bands are mainstream and generally pose lower hazard than uncoated textiles, which absorb moisture. However, premium alternatives (wool, silicone, canvas) either lack waterproofing entirely or use different coating chemistries. Coros does not distinguish itself as a PFAS-conscious or certified-safe brand in this category, placing it in the middle of the risk spectrum.
If you buy it
Rinse the band in cool water after salt water or heavy sweating to reduce skin contact with any coating residue. Do not expose to high heat (>60 C / 140 F), solvents, or prolonged chlorine, which can degrade coatings and increase leaching. Replace if the waterproof coating visibly peels, cracks, or flakes. If skin irritation, contact dermatitis, or rash develops around the wrist, discontinue use and consider switching to an uncoated or certified-safe alternative.
What we don’t know
- Basis
- Model estimate, 35% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Coros has made none
Formulations change between production runs, so check the current label. How we grade.
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More water-resistant smart rings & bands 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.