Table 3. Efficiency of the test mask with Micro Ventilator for filtration of particulates.

Conditioning of mask per EN149	% Penetration (mean ± SD, N=3)
	Sodium chloride (solid)	Paraffin oil (liquid)
As received	99.9%±0.0%	99.7%±0.0%
Simulated wearing	99.9%±0.0%*	99.4%±0.1%*
Mechanical strength and temperature conditioning	99.9%±0.0%	99.6%±0.1%
Overall (N=9)	99.9%±0.0%	99.6%±0.1%

This work was performed by INSPEC (Greater Manchester, UK). *, significantly different from the “as received” value by two-tailed t-test. SD, standard deviation.