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Breathability test result (pressure drops) and filter quality factor (QF)
| Face Covering Material | Pressure drop compared to the unobstructed response at an air flow rate of 85 L/min (Pa) | QF (kPa -1) |
|---|---|---|
| Silica | 152 (22 Pa/cm2) | 8.6 |
| Blank Control | 143 (20 Pa/cm2) | 4.6 |
| Cotton Face Covering | 166 (24 Pa/cm2) | 1.7 |
All data shown are representative of at least three independent experiments. The QF was calculated using Eq. 2 with the mean filter efficiency of cytochrome c.
