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Hydrophobic qualities of filter fabrics (colony forming units)
| Mask fabric | Tester 1 | Independent tester |
|---|---|---|
| IIR-surgical maska | 150 | 174 |
| ePM₁ 60%b | 120 | 95 |
| ePM₁ 85%b | 21 | 34 |
| F7b | 44 | 35 |
| F9 | 15 | 14 |
| M5b | 300 | 180 |
| Felt (155 g) | >1000 | >1000 |
| Quilt fabric | >1000 | >1000 |
| Tea towel | 800 | 800 |
| Laboratory paper towel | >1000 | >1000 |
Reference.
Commercially manufactured filter.
