Evaluation of the effectiveness of UV-C dose for photoinactivation of SARS-CoV-2 in contaminated N95 respirator, surgical and cotton fabric masks

Author(s)

Metolina, Patricia ; de Oliveira, Lilian Gomes ; Ramos, Bruno ; Angelo, Yan de Souza ; Minoprio, Paola ; Silva Costa Teixeira, Antonio Carlos

• Document type: Journal article
• Source: PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES; v. 21, n. 11, p. 15-pg., 2022-07-21.

Abstract

As part of efforts to combat the Covid-19 pandemic and decrease the high transmissibility of the new coronavirus, SARS-CoV-2, effective inactivation strategies, such as UV-C decontamination technologies, can be reliably disseminated and well-studied. The present study investigated the susceptibility of a high viral load of SARS-CoV-2 in filtering facepiece respirators (FFR) N95, surgical mask, cotton fabric mask and N95 straps under three different doses of UV-C, applying both real-time PCR (qPCR) and plaque formation assays to quantify viral load reduction and virus infectivity, respectively. The results show that more than 95% of the amount of SARS-CoV-2 RNA could be reduced after 10 min of UV-C exposure (0.93 J cm(-2) per side) in FFR N95 and surgical masks and, after 5 min of UV-C treatment (0.46 J cm(-2) per side) in fabric masks. Furthermore, the analysis of viable coronaviruses after these different UV-C treatments demonstrated that the lowest applied dose is sufficient to decontaminate all masks (similar to 3-log(10) reduction of the infective viral load, > 99.9% reduction). However, for the elastic strap of N95 respirators, a UV-C dose three times greater than that used in masks (1.4 J cm(-2) per side) is required. The findings suggest that the complete decontamination of masks can be performed effectively and safely in well-planned protocols for pandemic crises or as strategies to reduce the high consumption and safe disposal of these materials in the environment. (AU)

• FAPESP's process: 17/27131-9 - Integrated strategy for the study of infectious agents causing emerging and/or neglected diseases transmitted by vectors of global impact
• Grantee: Paola Marcella Camargo Minoprio
• Support Opportunities: Research Projects - Thematic Grants