- The Center for Disease Control and Prevention (CDC) do not recommend that filtering facepiece respirators (FFR) be decontaminated and then reused as standard care.
- In case of PPE shortage, the CDC has identified 3 effective decontamination methods based on their ability to inactivate pathogens and their effect on FFR
- Ultraviolet germicidal irradiation (UVIG): Nebraska medicine has created an FFR decontamination protocol with UVIG for COVID-19.
- Vaporous hydrogen peroxide (VHP): Duke University Health System and Boston University described the use of VPH to decontaminate FFRs.
- Moist Heat: In studies, SARS-CoV was inactivated after 30 to 60 minutes at 60°C/140°F.
- Some methods are promising, but they are not currently recommended by the CDC.
- Decontamination with liquid hydrogen peroxyde did not decrease the filtration capacity of the mask, but FFR fit and disinfection efficacy were not evaluated.
- According to the few studies on this subject, decontamination with steam treatment showed little effect on the filtration capacity of the mask. However, there is little information on the effectiveness of higher power microwaves and the potential danger of metal nosebands of FFRs in a microwave.
- Some methods were not recommended by the CDC.
- Decontamination methods such as autoclave, dry heat, isopropyl alcohol, soap and dry microwave irradiation affected the filtration capacity of the FFRs, which increased the level of particle penetration to a level higher than that accepted by NIOSH.
- Decontamination with bleach is not recommended as it affects the filtration capacity and creates an odor unsuitable for use.
- Decontamination with disinfectant wipes is not recommended as their disinfection efficacy and effect on the filtration capacity of the FFR varied depending on the type of wipe and the model of FFR.
- After decontamination, FFR should not be worn for aerosol generating procedure
This data comes mainly from CDC guidelines on the optimization of PPE supply. This document describes some techniques for decontaminating FFRs in case of shortage. Lowe J.J. et al. described a decontamination technique using UVGI and Schwartz A. et al. described a decontamination technique using VPH. Duan S.M. et al. studied the stability of SARS-CoV in human specimens and in environments. Oral E. et al. studied the effectiveness of the decontamination technique using VPH.
1. Center for Disease Control and Prevention (April 1, 2020). Decontamination and Reuse of Filtering Facepiece Respirators. Retrieved from:https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/decontamination-reuse-respirators.html
2. Lowe J.J., Paladino K.D., Farke J.D., et al. N95 Filtering Facepiece Respirator Ultraviolet Germicidal Irradiation (UVGI) Process for Decontamination and Reuse. Retrieved from: https://www.nebraskamed.com/sites/default/files/documents/covid-19/n-95-decon-process.pdf?date=03252020
3. Schwartz A., Stiegel M., Greeson N., et al (March 27, 2020). Decontamination and Reuse of N95 Respirators with Hydrogen Peroxide Vapor to Address Worldwide Personal Protective Equipment Shortages During the SARS-CoV-2 (COVID-19) Pandemic. ABSA International: The Association for Biosafety and Biosecurity.https://absa.org/decontamination-and-reuse-of-n95-respirators-with-hydrogen-peroxide-vapor-to-address-worldwide-personal-protective-equipment-shortages-during-the-sars-cov-2-covid-19-pandemic/ç
4. Duan S.M., Zhao X.S., Wen R.F., et al (September 2003). Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation. Biomed Environ Sci. https://www.ncbi.nlm.nih.gov/pubmed?term=14631830
5.Oral E., Wannomae K. K., Connolly R., et al (April 16, 2020).Vapor H2O2 sterilization as a decontamination method for the reuse of N95 respirators in the COVID‐19 emergency. MedRxiv. https://doi.org/10.1101/2020.04.11.20062026