Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026) vs Smart Ring Pro, No App Subscription, Sleep & Activity Tracker with Heart Rate Monitoring, 7 Days Battery Life, IP68 Wate: which is safer?
Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026) is the clear pick. Smart Ring Pro, No App Subscription, Sleep & Activity Tracker with Heart Rate Monitoring, 7 Days Battery Life, IP68 Wate carries a failing PFAS grade, and we never recommend buying a failing product.
Our pick
Fitbit
Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026)
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleElectronic component off-gassing or thermal breakdown
ReportedBiofilm and bacterial growth on sensor surfaces
PossibleGlass or metal micro-debris from wear
Polar
Smart Ring Pro, No App Subscription, Sleep & Activity Tracker with Heart Rate Monitoring, 7 Days Battery Life, IP68 Wate
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleUndisclosed waterproof coating chemistry
PossibleNickel or other alloying metals in direct skin contact
LikelyCoating degradation and micro-shedding over time
Both products run through the same public rubric: materials, coatings, brand disclosure, lab findings, and recalls, plus a beyond-PFAS hazard analysis. Grades are model-based estimates, not lab tests. How grades work →
More waterproof smart rings & bands: see the full ranking