Fitbit · Waterproof Smart Rings & Bands
Smart Ring Health Tracker
Unspecified waterproof coating raises PFAS concern. Insufficient transparency.
Fitbit does not disclose waterproof treatment chemicals used in this smart ring. Common coatings in wearables often contain PFAS; brand silence leaves risk unclear.
The safe swap
Fitbit
Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026)
85/100 safety
Still want this one anyway? Check the price on Amazon. We’d swap it.
Material
Stainless steel band, polymer sensors, waterproof coating unspecified
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
other 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
The Fitbit Smart Ring uses a stainless steel band (inert, non-leaching) paired with polymer-based sensors and an unspecified waterproof or water-resistant coating. Stainless steel itself is stable against skin contact, but the polymer sensor materials and the waterproof treatment are the chemical unknowns. Waterproof coatings on wearables often use Teflon-family coating or other treatments that may contain PFAS, though Fitbit does not disclose the specific formulation.
The brand's record and disclosure
Fitbit (owned by Google since 2021) does not publicly disclose material composition, waterproof coating chemistry, or PFAS testing for this device. The company has not published sustainability reports that address wearable-specific material safety or PFAS avoidance strategies. This silence is typical for consumer wearables but contrasts with leading personal care brands that now voluntarily test and report on PFAS in waterproof products.
How it compares in its category
Smart rings and wearables rarely disclose waterproof coating details; Fitbit's opacity is industry standard, not exceptional. Competitors like Oura Ring and Samsung Galaxy Ring have similar or worse transparency. Few wearables undergo independent third-party testing for PFAS or heavy metals in polymer sensors, so direct comparison is difficult. The stainless steel band places this product in a safer material category than silicone-only alternatives, which can off-gas volatile compounds.
If you buy it
Rinse the ring with fresh water after exposure to chlorine or saltwater to reduce buildup on the coating. Remove the ring during hot showers or saunas (heat can stress polymer coatings and may increase leaching). Inspect the stainless steel band periodically for scratches or discoloration; a damaged coating warrants replacement or temporary removal. Clean with mild soap and dry thoroughly to prevent moisture trapping, which can degrade the polymer components over years of use.
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.”
Waterproof coating composition (unspecified)
Fitbit does not disclose whether the waterproof treatment uses Teflon-family coating, siloxanes, or other chemistries. Teflon-family coating-based coatings commonly contain PFAS, though non-PFAS alternatives exist. Without testing or disclosure, PFAS and other coating leachables cannot be ruled out.
Polymer sensor materials
Fitbit does not identify the specific polymers in heart-rate and motion sensors. Typical elastomer and plastic formulations may include plasticizers or flame retardants, but no recalls or complaints specific to this ring are on record. Risk is low but unvalidated due to lack of transparency.
Skin sensitivity to nickel in stainless steel
Stainless steel typically contains nickel (often 8-12% in 304/316 grades). Some wearers with nickel sensitivity may experience contact dermatitis with prolonged daily wear. This is material-specific but not brand-specific; happens with most metal wearables.
Polymer degradation and microparticle shedding
Extended wear, heat exposure, and friction can cause polymer components to degrade. No data exists on shedding rates or toxicity of shed particles from Fitbit's specific formulations. Risk is theoretical but worth monitoring if the ring is worn for years continuously.
Battery enclosure leakage
The battery compartment is sealed but not user-accessible. No established recall history for battery electrolyte leakage in Fitbit rings. Risk is low given the sealed design, but water damage or manufacturing defects could theoretically expose battery chemicals.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 35% 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 Waterproof Smart Rings & Bands
Fitbit
Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026)
Titanium and stainless steel with glass sensor
Lower concern smart ring; no PFAS-prone materials identified.
⚠Brand says nothing about PFAS
Fitbit
Qalo QRNT Slim Smart Ring
silicone elastomer with metal core
Smart ring with silicone body; lower concern but no public PFAS disclosure.
⚠Brand says nothing about PFAS
Withings
Black Smart Ring Size 9 - New Women | Color: Black
Titanium alloy ring with sapphire crystal display
Lower concern. Smart ring materials inherently unlikely to require PFAS.
⚠Brand says nothing about PFAS
More waterproof 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.