Chrono 42 Quartz Watch vs Smart Band 9: which is safer?
Swatch Chrono 42 Quartz Watch is the clear pick. Xiaomi Smart Band 9 carries a failing PFAS grade, and we never recommend buying a failing product.
Our pick
Swatch
Chrono 42 Quartz Watch
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleMineral crystal breakage and laceration
PossibleBattery chemical leakage (internal only)
Xiaomi
Smart Band 9
PFAS grade
Overall grade
Verdict
Hazard flags
Material
Confidence
PossibleWaterproof coating composition (PFAS likelihood)
PossibleSilicone band degradation and additive migration
PossibleSeal integrity and bacterial/fungal growth
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 smartwatches & fitness trackers: see the full ranking