Fitbit · Water-Resistant Smart Rings & Bands
Mykomi Waterproof Bands for Fitbit Versa 3 / Fitbit Versa 4 / Fitbit Sense
No coating described, and no PFAS statement from the brand.
The product information we reviewed describes silicone elastomer, with no water-repellent coating named. Water resistance on products like this usually comes from the material and its seals rather than a surface treatment. The brand has published no PFAS statement for it.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Silicone elastomer
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
What’s concerning
Category baseline
The starting point for this type of product, before anything specific to this product is counted.
No PFAS disclosure
No public statement from the brand about PFAS in this product.
Silicone degradation over time
Silicone elastomer can lose elasticity and develop micro-tears with prolonged UV exposure or high heat. No recalls or complaints specific to Mykomi bands are on record, but this is a material-class aging mechanism, not a chemical toxicity risk.
Bacterial or fungal colonization
Any elastomer band can trap moisture in seams and under the watch face if not dried promptly after water exposure. This is a hygiene issue rather than a material toxicity concern. Regular cleaning mitigates risk.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Volatile organic compound (VOC) off-gassing
High-quality silicone elastomer has minimal off-gassing under normal wrist temperature conditions. No odor or respiratory complaints linked to Mykomi or similar silicone bands are documented. Some users report a faint rubber smell on first use, which dissipates within days and is not a health hazard.
Heavy metals
Silicone is colored by polymer-bound dyes, not surface coatings or pigment pastes. Mykomi bands are not reported to leach color or metals. No third-party testing results are publicly available, but the material and application method present low risk compared to painted or dyed textiles.
Source, FDA ↗Formaldehyde / VOCs
Silicone elastomer does not require formaldehyde-releasing resins or flame retardants. Antimony is not used in standard silicone chemistry. No evidence of these additives in Mykomi bands or other silicone sport bands exists in public safety databases.
Source, ATSDR ↗The full breakdown
What it's made of and why it matters
Mykomi bands are silicone elastomer, a synthetic rubber polymer chosen for water resistance and durability in wearable applications. Silicone does not inherently leach BPA, phthalates, or heavy metals under normal use conditions. Unlike some thermoplastic elastomers or PVC alternatives, silicone is chemically inert and resistant to breakdown from sweat, saltwater, and repeated temperature cycling. The band's waterproof rating depends on mechanical seals and the silicone material itself, not chemical coatings.
The brand's record and disclosure
Fitbit (owned by Google since 2021) has not published specific material safety certifications or PFAS statements for their band products. The brand does not appear in major product safety recalls related to wearable bands. Fitbit provides standard care instructions but does not disclose third-party testing results for leaching or off-gassing. This silence is typical for the wearable accessory market and does not indicate a known problem.
How it compares in its category
Silicone bands show lower concern compared to leather (which may be treated with heavy-metal dyes), fabric (which can harbor bacteria), and some cheaper elastomers with unclear composition. Most major wearable manufacturers (Apple, Garmin, Samsung) also use silicone for sport bands. Mykomi's third-party status means fewer official certifications than Fitbit-branded bands, but the material class itself carries lower risk than many competitors.
If you buy it
Rinse the band with fresh water after saltwater exposure and dry it fully to prevent bacterial or fungal buildup in crevices. Do not expose to prolonged direct sunlight or temperatures above 60 degrees Celsius (140 degrees Fahrenheit), as extended heat can degrade silicone elasticity over years of use. Replace if you notice cracking, discoloration, or persistent odor. Clean monthly with mild soap and water; avoid harsh solvents.
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
- Fitbit has made none
Formulations change between production runs, so check the current label. How we grade.
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.