The influence of various disinfection methods on the filtration and bactericidal performance was investigated for Resp. A and Resp. B. The 3D images of layer constructions for those respirators were analyzed by the X-ray computed tomography (Xμ-CT) (Figure 1). Common components of respirators included: a spunbond coverweb, one or two layers of electrostatically charged meltblown filter webs, and a spunbond inner web. respirator A (Resp. A) had an additional stiffener web and 2 layers of meltblown webs. The meltblown filter web was comprised of very thin fibers <2.5 μm in a considerable portion. In contrast, respirator B (Resp. B) consisted of a single layer filter web of which fiber diameter ranged from 2.5 μm to 12.5 μm. The thickness of each layer of the respirators was measured firsthand with a thickness gauge applying a pressure of 2.4 N, and is presented in Figure 1C,F. It is noted that the measurements by the gauge were smaller than those estimated from the specific locations of Xμ-CT images. When analyzing the morphological changes in the later sections, first-hand measurements were used.