Decontamination of disposable respirators for reuse in a pandemic employing in-situ-generated peracetic acid

Boeing, Christian; Sandten, Christian; Hrincius, Dr Eike R; Anhlan, Dr Darisuren; Dworog, Dr Andreas; Hanning, Stephanie; Kuennemann, Thilo; Niehues, Prof Dr Christopher; Schupp, Prof Dr Thomas; Stec, Dr Edyta; Thume, Julius; Triphaus, Daniel; Wilkens, Dr Markus; Uphoff, Dipl Ing Holger; Zuendorf, Dr Josef; Jacobshagen, Dr Anja; Kreyenschmidt, Prof Dr Martin; Ludwig, Prof Dr Stephan; Mertins, Prof Dr Hans-Christoph; Mellmann, Prof Dr Alexander

BACKGROUND: During shortages of filtering face pieces (FFP) in a pandemic, it is necessary to implement a method for safe reuse or extended use. Our aim was to develop a simple, inexpensive and ecological method for decontamination of disposable FFPs that preserves filtration efficiency and material integrity. MATERIAL AND METHODS: Contamination of FFPs (3M Aura 9320+) with SARS-CoV-2 (1.15 × 104 PFUs), Enterococcus faecium (>106 CFUs), and physiological nasopharyngeal flora was performed prior to decontamination by submersion in a solution of 6 % acetic acid and 6 % hydrogen peroxide (6%AA/6%HP solution) over 30 minutes. Material integrity was assessed by testing the filtering efficiency, loss of fit and employing electron microscopy. RESULTS AND DISCUSSION: Decontamination with the 6%AA/6%HP solution resulted in the complete elimination of SARS-CoV-2, E. faecium and physiological nasopharyngeal flora. Material characterization post-treatment showed neither critical material degradation, loss of fit or reduction of filtration efficiency. Electron microscopy revealed no damage to the fibers, and the rubber bands' elasticity was not affected by the decontamination procedure. No concerning residuals of the decontamination procedure were found. CONCLUSION: The simple application and widespread availability of 6%AA/6%HP solution for decontaminating disposable FFPs make this solution globally viable, including developing and third world countries.