What are reasonable cleaning/disinfection/sterilization methods for N95 respirators?
N95 respirators can be decontaminated effectively and maintain functional integrity for up to three uses, according to National Institutes of Health scientists. Decontamination methods tested included vaporized hydrogen peroxide (VHP), 70-degree Celsius dry heat, ultraviolet light, and 70% ethanol spray. In this study, VHP was the most effective decontamination method, because no virus could be detected after only a 10-minute treatment. UV and dry heat were acceptable decontamination procedures as long as the methods are applied for at least 60 minutes. Ethanol spray damaged the integrity of the respirator's fit and seal after two sessions. The authors urge anyone decontaminating an N95 respirator to check the face fit and seal before each re-use.
The CDC provides additional information on these and other decontamination processes, and practical alternatives, including using a limited supply of N95s signed out to clinical staff and rotated across days – being stored in a paper bag labeled with the individual’s name for 5 days to ensure viral dessication before re-use.
FEMA has published information regarding a number of sterilization systems including a Battelle-delivered service called Critical Care Decontamination System™ . Existing hospital sterilization systems that have been granted FDA Emergency Use Authorization (EUA) and the CCDS™ use vaporous hydrogen peroxide.
Fischer R, Morris DH, van Doremalen N, Sarchette S, Matson J, et al. Assessment of N95 respirator decontamination and re-use for SARS-CoV-2. BMJ medRxiv 2020April preprint. Accessed May 3, 2020 at: https://www.medrxiv.org/content/10.1101/2020.04.11.20062018v2.full.pdf
U.S. Centers for Disease Control and Prevention: Coronavirus Disease 2019 (COVID-19): N95 Respirators. Accessed April 28, 2020 at: https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirators-strategy/index.html
FEMA Fact Sheet: Using the Critical Care Decontamination System™ April 30, 2020. Available at: https://www.fema.gov/news-release/2020/04/30/using-critical-care-decontamination-systemtm