Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026) vs Black Smart Ring Size 9 - New Women | Color: Black: which is safer?
These two grade almost identically. Pick on price and preference; neither has a PFAS edge.
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
Withings
Black Smart Ring Size 9 - New Women | Color: Black
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleNickel leaching from alloy
ReportedBiofilm and bacterial growth under ring
PossibleAdhesive or sealant leachables at joints
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