Table 2 Results obtained at a university laboratory on single-pass filtration efficiency for ambient particle matter. Each row represents a single N95 mask. Filtration efficiency values are an average of four upstream and downstream measurements. Standard deviations are calculated from repeat measurements made on a single mask.

0

97.66% (0.18)

99.05% (0.13)

99.68% (0.03)

0

97.53% (0.18)

99.11% (0.23)

100.00% (0.00)

1

99.20% (0.08)

99.70% (0.08)

99.90% (0.20)

2

98.98% (0.10)

99.80% (0.06)

100.00% (0.00)

2

99.42% (0.05)

99.89% (0.09)

99.91% (0.18)

3

99.36% (0.12)

99.92% (0.06)

100.00% (0.00)

4

98.55% (0.07)

99.59% (0.13)

99.88% (0.24)

5

98.76% (0.03)

99.52% (0.16)

100.00% (0.00)

10

98.45% (0.15)

99.39% (0.09)

100.00% (0.00)

0

99.91% (0.02)

99.95% (0.05)

100.00% (0.00)

1

99.83% (0.07)

99.86% (0.17)

100.00% (0.00)

2

99.91% (0.02)

99.98% (0.02)

100.00% (0.00)

3

99.90% (0.04)

99.98% (0.04)

100.00% (0.00)

4

99.69% (0.06)

99.80% (0.12)

99.89% (0.24)

5

99.89% (0.03)

99.95% (0.07)

100.00% (0.00)

10

99.86% (0.07)

99.97% (0.06)

100.00% (0.00)

1

96.06% (0.20)

98.90% (0.10)

99.68% (0.43)

2

96.46% (0.19)

99.08% (0.11)

99.84% (0.19)

3

95.17% (0.37)

98.80% (0.26)

99.65% (0.30)

0

98.09% (0.22)

99.42% (0.24)

99.82% (0.21)

1

99.86% (0.04)

99.99% (0.02)

100.00% (0.00)

2

99.52% (0.03)

99.93% (0.04)

100.00% (0.00)

3

99.28% (0.06)

99.88% (0.04)

100.00% (0.00)

4

98.90% (0.11)

99.40% (0.10)

100.00% (0.00)

10

99.16% (0.15)

99.77% (0.13)

100.00% (0.00)

0

99.75% (0.11)

99.92% (0.11)

100.00% (0.00)

1

99.77% (0.16)

99.83% (0.19)

99.71% (0.37)

2

99.70% (0.07)

99.92% (0.07)

100.00% (0.00)

3

99.39% (0.18)

99.86% (0.04)

100.00% (0.00)

4

98.68% (0.98)

99.01% (0.92)

99.05% (1.19)