Charge 6 Activity Tracker Smart Ring Size 9 Silver Black vs Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026): which is safer?

Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026) is the clear pick. Fitbit Charge 6 Activity Tracker Smart Ring Size 9 Silver Black carries a failing PFAS grade, and we never recommend buying a failing product.

Fitbit

Charge 6 Activity Tracker Smart Ring Size 9 Silver Black

PFAS grade

F 40/100

Overall grade

F 28/100

Verdict

Skip

Hazard flags

⚑ 3

Material

Stainless steel, elastomer, unknown waterproof coating

Confidence

45%

PossibleElastomer band composition (phthalates/plasticizers)

PossibleWaterproof coating leachables

PossibleStrap degradation and microparticle release

Why this grade

Our pick

Fitbit

Oura - Ring 5 - Smart Ring - Size Before You Buy with OR5 Sizing Kit - Size 11 - Silver - (2026)

PFAS grade

B 85/100

Overall grade

D 67/100

Verdict

Buy

Hazard flags

⚑ 3

Material

Titanium and stainless steel with glass sensor

Confidence

72%

PossibleElectronic component off-gassing or thermal breakdown

ReportedBiofilm and bacterial growth on sensor surfaces

PossibleGlass or metal micro-debris from wear

Why this gradeBuy

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