Filtering efficiency measurement of respirators by laser-based particle counting method

Abstract

Graphical abstract

Microstructural evaluation and recommendations for face masks in community use to reduce the transmission of respiratory infectious diseases

“…Under these assumptions and limitations, the model provides a microscopic insight with time intervals of that agrees well with the recent particle image velocimetry experiments [70] . The results were also observed to be in line with the recent experimental results [87] , [88] , showing the trade-off between the PFE and breathability in terms of air permeability. Especially, for the intermediate sizes of 0.1µm-0.3µm, the particles were obtained to be hardly captured by face masks with two non-woven layers as seen in Fig.…”

“…In line with the recent studies on transmitted particle sizes [83] , [86] , [87] , the particle diameter range of {0.1, 0.3, 0.5, 1.0, 2.0} µm was investigated. The present numerical model with the reconstructed face mask layers did not take the particle emission and flow speed variations into account because of the scale and duration of interest, following the previous studies in the literature [44] .…”

Biocompatibile nanofiber based membranes for high-efficiency filtration of nano-aerosols with low air resistance

“…Furthermore, this study found that the corresponding pressure loss is considerably low. As part of the efforts to control the COVID-19 pandemic, recent literature proposed that using face masks effectively reduces virus transmission ( Illés and Gordon 2021 ; Emma et al, 2020). In this study, filtration efficiency and pressure loss were associated with the PI/PES filtration performance, which was used as a barrier to effectively protect the wearer against nano-aerosols, including the viral aerosols of COVID-19 and UFPs from combustion emissions.…”

Electrospun nanofibers for medical face mask with protection capabilities against viruses: State of the art and perspective for industrial scale-up

“…2 c). With regards to the EN 149:2001, these respirators are classified as filtering half masks (i.e., Filtering Face Pieces (FFP)) and are divided in three different types, namely FFP1, FFP2, and FFP3, depending on the filtration efficiency values, for both PFE and BFE, equal to 80%, 94%, and 99%, respectively [44] , [45] , [46] ( Table 1 ). In addition to the filtration performance, the National Institute for Occupational Safety and Health (NIOSH), in the USA, also adopts a classification by letter, namely N-, R-, and P-, to indicate the lack of resistance in oil, somewhat oil resistant, and strongly resistant, respectively.…”