Withings · Waterproof Smartphone Cases
Smartwatch Withings Steel HR Sport
No coating described, and no PFAS statement from the brand.
The product information we reviewed describes stainless steel case, possibly water-resistant polymer gaskets, 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
Stainless steel case, possibly water-resistant polymer gaskets
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.
BPA & bisphenols
Water-resistant gaskets are typically synthetic rubber or elastomer, materials that can contain plasticizers. However, gaskets are small, sealed, and not in prolonged contact with skin or ingestion routes, making practical exposure unlikely.
Source, FDA ↗Stainless steel leaching (nickel)
Stainless steel contains trace nickel and can leach it slightly in sweat or salt water, especially if the surface is scratched. This is relevant only for users with documented nickel sensitivity; the risk is present but low for most wearers.
Bacterial growth in water-resistant seals
If gaskets trap moisture and are not dried properly between uses, bacteria or mold could colonize the seal interface. Regular rinsing and air-drying after water exposure mitigates this.
Silicone or rubber band additives (if interchangeable band used)
Replacement bands sold separately may contain uncertified elastomers or colorants. If you swap the stock band, verify third-party bands meet EU or US material safety standards.
What’s reassuring
Base material not linked to PFAS
The main material recorded for this product is not one associated with PFAS.
Electronic component off-gassing
The internal battery and circuit board are sealed from the user by the steel case and gaskets; no volatile organic compounds or solder fumes are reported to escape during normal wear.
The full breakdown
What it's made of and why it matters
The Withings Steel HR Sport uses a stainless steel case paired with water-resistant polymer gaskets to achieve its 5 ATM water resistance rating. Stainless steel itself is inert and does not leach metals or release volatile compounds under normal wear. The polymer gaskets are the only material component that could theoretically degrade or leach plasticizers, but their small mass, sealed orientation, and no direct skin contact minimize exposure pathways.
The brand's record and disclosure
Withings has published no formal material safety disclosures or PFAS statements for this model, which is typical for wearable electronics brands and does not indicate a compliance gap. The company has no known product recalls or safety controversies tied to chemical hazards in its wearable line. Absence of a statement is not evidence of risk; it reflects the industry norm for smartwatch documentation.
How it compares in its category
As a hybrid smartwatch with minimal plastic exposure, the Steel HR Sport has lower concern than fully polymeric sports watches or those with silicone bands that may contain phthalates or uncertified additives. Traditional steel-cased mechanical watches and sport variants share similar inert-metal designs. It occupies a lower-risk position within the wearable category due to material simplicity and sealed construction.
If you buy it
Rinse the watch with fresh water after saltwater or chlorinated swimming to prevent gasket degradation and corrosion. Replace the band gasket or seals if the watch loses water resistance over time or if cracks appear around the case edges. Avoid prolonged exposure to extreme heat (sauna, direct sun for hours) which may soften polymer gaskets; stainless steel itself is stable. Clean the case with a soft cloth; do not use harsh chemicals or abrasive scrubbing.
What we don’t know
- Basis
- Model estimate, 45% confidence, not a lab result
- Lab test
- None on record for this exact product
- Brand statement
- Withings has made none
Formulations change between production runs, so check the current label. How we grade.
More waterproof smartphone cases 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.