The protective performance of reusable cloth face masks, disposable procedure masks, KN95 masks and N95 respirators: Filtration and total inward leakage
Fig 9
Protection performance results for the five mask groups; fabric 2-layer masks (2-L), multi-layer masks (M-L), disposable procedure masks (PMs), KN95 masks and N95 FFRs.
TILPF—total inward leakage protection factor. FPF—fabric protection factor (overall protection of fabric material against entire particle size distribution). FF—fit factor (total inward leakage measured through face seal only (by QNFT). Sample sizes: n = 8 to 26 for TILPF; n = 6 to 20 for FPF; and; n = 30 for FF. The geometric mean is shown by the square marker.