Table 4. Inward Leakage (IL) and filter penetration for 10 models of FFRs in this study.

Respirator model	No. of testing	Geometric mean IL (%)	GSD (%)	95th percentile IL (%)	Mean filter penetration (%)	SD (%)
A1	150	4.8	2.1	16.1	0.006	0.004
A2	150	7.0	2.3	27.0	0.066	0.050
B1	150	7.0	2.8	38.1	0.003	0.005
B2	150	7.2	2.1	24.6	0.009	0.004
C1	150	12.2	2.1	39.8	0.002	0.000
C2	150	11.0	2.4	44.9	1.119	0.513
C3	150	14.4	1.9	41.4	0.004	0.001
C4	150	17.7	2.0	53.3	0.013	0.010
D1	150	1.4	2.7	6.8	0.005	0.001
D2	150	2.2	2.3	8.5	0.137	0.132
Total	1500	6.7	3.1	42.2	0.136	0.364

Abbreviation: IL, Inward leakage; FFR, Filtering facepiece respirator; GSD, geometric standard deviation, SD, standard deviation.