In general, liquid PAA is a powerful oxidizer already at low concentrations (from 0.005% to 0.3%) ( 8, 9), with high efficacy against viruses, bacteria, bacterial spores, and mycobacteria, and can be used within a wide temperature range (from −40 to +20☌) ( 10). The dispersion of aPAA-HP in ultrafine particles has recently been described as very effective ( 6, 7). Here, we compared the efficacy of an aerosolized mixture of peroxyacetic acid and hydrogen peroxide (aPAA-HP) against a wide range of microorganisms under different conditions. Besides the effectiveness, the corrosiveness of these disinfection methods must also be assessed. In most settings, after wet chemical cleaning and disinfection of easily accessible surfaces, airborne disinfection with gaseous formaldehyde ( 1, 2) or vaporized hydrogen peroxide is conducted to reach otherwise inaccessible surfaces ( 3 – 5). The disinfection of laboratories and animal rooms in high-containment environments is complex, and effective procedures are required to render an area biologically safe, e.g., between animal studies or for maintenance access. Furthermore, CSC are artificial bioindicators with lower resistance and thus should not be used for validating airborne disinfection when microorganisms other than viruses have to be inactivated. Overall, we conclude that dry fogging a mixture of aPAA-HP is highly effective against a broad range of microorganisms as well as material compatible with relevant concentrations. Furthermore, we found striking differences in inactivation efficacies against some of the tested microorganisms. Relevant process parameters such as temperature and relative humidity can be wirelessly monitored. Our results demonstrate that aPAA-HP is a highly efficient procedure for airborne room disinfection. We then used the QCT methodology to determine relevant process parameters to develop and validate effective disinfection protocols (≥4-log 10 reduction) in various large and complex facilities. We used quantitative carrier testing (QCT) procedures to compare the sensitivity of CSC with that of surrogates for nonenveloped and enveloped viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), mycobacteria, and spores, to an aerosolized mixture of peroxyacetic acid and hydrogen peroxide (aPAA-HP). Commercial spore carriers (CSC) coated with 10 6 spores of Geobacillus stearothermophilus are often used to assess the efficacy of disinfection. Airborne disinfection of high-containment facilities before maintenance or between animal studies is crucial.
0 Comments
Leave a Reply. |