NIH Validates Four Decontamination Methods
A government study has validated that four decontamination methods remove detectable viable SARS-CoV-2 virus from small sections of filter fabric from N95 filtering facepiece respirators, according to the National Institutes of Health. Investigators tested methods involving vaporized hydrogen peroxide, 70-degree Celsius dry heat, ultraviolet light, and 70 percent ethanol spray, then treated fully intact respirators with each method to determine their effects on reuse durability. Vaporized hydrogen peroxide, or VHP, was the most effective method. After a ten-minute treatment, no viable virus could be detected. Respirators treated with VHP experienced no failures, which suggests they can be reused up to three times. Ultraviolet light and heat treatments caused fit and seal problems after three decontaminations, which suggests these treatments can allow respirators to be used twice. Ethanol spray damaged the respirators’ fit and the integrity of their seal after two decontamination sessions, and therefore is not recommended. The investigators urge anyone decontaminating a respirator to test the fit and seal before each reuse. For more information, visit the website of the National Institutes of Health.