Effects of Various Physical and Chemical Disinfection Methods on the Fine Particle Collection Efficiency of N95 Respirators and Surgical Masks

Abstract

There have been many reports on the effectiveness of various disinfection methods for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and their applicability to the disinfection of N95 respirators and surgical masks. To date, there have been no reports on the decontamination of the intermediate layers. In this study, the conditions required for the decontamination of such layers were set by simulation considering the thickness and shape of the N95 respirators or surgical masks (samples).After applying heat (steam, dry heat, or hot water) at 75°C for 60 min or chemical (benzalkonium chloride or laundry detergent) treatment, the collection efficiency of the samples was checked and evaluated. After the dry heat treatment, the time between treatment and when the heat reached the intermediate layer of the filter fiber was extended by 10 min. A dry heat disinfection method that combines hot water and a closed container was also evaluated, and satisfactory conditions were extended by 60 min. For each heat treatment, there was almost no effect on the collection efficiency, although there were cases where deformation was caused by mechanical stress. In contrast, chemical treatment resulted in a reduction in the collection efficiency of smaller particles.

Comparative Evaluation of Microorganism Disinfection Methods for N95 Respirators

“…In this study, we confi rmed that conventional pasteurisation is the most eff ective decontamination method. Iki S, et al [20] also reported the effi ciency of high-heat (75 °C) disinfection [20]. Although we did not evaluate the proper fi tting after the decontamination process, the pasteurisation process does not aff ect the form of the respirator.…”