Abstract
The filter efficiency of seven kinds of commercial face mask for particles and airborne bacteria was tested in the wash room of a laboratory animal facility. The filter efficiency of the masks was 19 to 50%, as measured by the weight of particles with diameters below 10μm, 22 to 71% for particles of the 0.3μm level, 47 to 906 for the 1μm level, and 90 to 99.606 for the 5 1μm level. The filter efficiency for airborne bacteria was 35 to 81%. Among thes even masks tested, glasswool surgery masks, three-sheet synthetic fiber masks with and without charcoal, and 28-sheet gauze masks with glass filter showed generally high efficiency, and single-sheet synthetic fiber masks, 18-sheet of gauze masks and gas masks showed low efficiency.
