Penetration of different nanoparticles through melt-blown filter media used for respiratory protective devices

Abstract

The appearance of new dangers in the form of harmful aerosols containing nanoparticles has necessitated work on ensuring effective protection of humans’ respiratory systems. So far, there is no uniform method, which would make it possible to classify filtering devices, for evaluating the efficiency of respiratory protective devices against nanoaerosols. The authors assessed the morphology of various nanoaerosols of NaCl, titanium dioxide in two forms, anatase and rutile, and aluminosilicate based on observations using a scanning microscope. Then the efficiency of filtration of meltblown fabrics with surface densities of 30, 50, 70, and 90 g/m2 against those nanoaerosols were tested. The experimental results were subjected to the theoretical analysis based on filtration theory. For all the fabric types, similar filtration efficiencies were obtained irrespective of the morphological structure of the nanoaerosol particles. The theoretical predictions are in good agreement with the experimental results. The conclusion is therefore drawn that equipment can be evaluated based on testing of filtration efficiency against any tested aerosols.