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Mean reduction in sunscreen brightness, the estimated amount of sunscreen remaining and the estimated sun protection factor (SPF) at every 2‐hour time point
| Time point | Mean reduction in brightness % (range) | Estimated amount of remaining sunscreen (mg/cm2) | Estimated SPF |
|---|---|---|---|
| Baseline | 0.0 (0–0) | 2.00 | 50+ |
| 2 hours | 18.31 (4.21‐36.31) | 1.63 | >30 |
| 4 hours | 24.77 (11.12‐38.97) | 1.50 | <30 |
| 6 hours | 28.63 (14.25‐39.69) | 1.43 | <25 |
| 8 hours | 31.63 (17.39‐45.29) | 1.37 | <25 |
