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Received: January 10, 2024; Revised: February 03, 2024; Accepted: March 01, 2024
Abstract: Objectives: The coronavirus pandemic that began in 2019(COVID-19) has been one of the worst pandemics of the 21st century. Masks have been used to prevent COVID-19, but there are currently no standards for the long-term use of masks in the Republic of Korea. This study was conducted to assess the microbiological safety of KF94(Korea Filter 94) disposable face masks according to wearing duration by evaluating the bacterial filtration efficiencies of masks worn by research participants. Methods: A commercially available KF94 mask certified by the Ministry of Food and Drug Safety(MFDS) in the Republic of Korea was selected as the test mask. The research participants(n = 15) wore masks for the durations of one, three, and seven days. Participants also reported several parameters, including wearing time, makeup frequency, and storage. Bacterial filtration efficiencies of the worn masks were measured by a mask bioaerosol filtration tester. Staphylococcus aureus(S. aureus) was used as the test bacteria and quantitatively measured through the cultivation method. Then, bacterial filtration efficiency was calculated using the formula suggested by the MFDS. Results: All worn masks showed over 99.98% of mean bacterial filtration efficiency for S. aureus. There were no significant differences among bacterial filtration efficiencies of face masks according to wearing duration. There was also no significant difference among bacterial filtration efficiencies among participants. There was no correlation between the results of bacterial filtration efficiencies and reported parameters from participants. Conclusions: In the absence of significant external damage to the mask, the bacterial filtration efficiency of the mask can be maintained even after seven days of wearing. This result suggests that KF94 masks certified by the MFDS can be used repeatedly for about a week without loss of bacterial filtration efficiency.