Safety and structural integrity of N95/PFF2 respirators decontamination

Coelho, Wanderson Eduardo Gomes de Souza; Perrechil, Fabiana; Pedreira, Mavilde L.G.; Lopes, Juliana Lima; Santos, Maria Valdenice Lopes dos; Gabrieloni, Maria Cristina; Perfeito, João Alessio; Moraes, Mariana Agostini de; Taminato, Monica

COVID-19 is caused by the SARS-CoV-2 virus, an emerging respiratory pathogen. The work environment represents a high risk factor for health professionals. Given the scarcity of protective personal equipment (PPE) due to global demand, decontamination and reuse studies should be carried out. Thus, the aim of this study was to evaluate the safety of a method of decontamination of N95/PFF2 respirators, especially regarding structural integrity. For that, N95/PFF2 respirators were subjected to hydrogen peroxide decontamination and analyzed using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Seven respirators of the same brand and lot were used, one being a control and the other six subjected to decontamination process. As for the sealing, a qualitative test was applied, in order to identify the changes in the structure that could damage the sealing of respirators. Results indicated that the fiber morphology in all layers was not affected by the six decontamination cycles. Also, the thermal stability in the different layers was very similar. Fit testing showed that the respiradors submitted to all cycles of decontamination were approved. Thus, it is possible to conclude that the hydrogen peroxide decontamination method is effective, since it does not alter the physical properties of the respirators.