Methicillin-resistant Staphylococcus aureus (MRSA) is not eradicated with low-concentration hydrogen peroxide airborne treatment, according to the latest research published recently. A comparative study conducted by an independent laboratory, published in Letters in Applied Microbiology (Murdoch LE, Bailey L, Banham E, Watson F, Adams NM, Chewins J. Evaluating different concentrations of hydrogen peroxide in an automated room disinfection system. Lett Appl Microbiol 2016 Jun 21. doi: 10.1111/lam.12607 [Epub ahead of print]), tested the efficacy of 5%, 10% and 35% weight by weight (w/w) hydrogen peroxide solutions when used with an automated room disinfection system.
The results showed that both the 5% and 10% solutions failed to kill MRSA and reached a 6-log kill of Geobacillus stearothermophilus after 70 minutes (5% solution) and 40 minutes (10% solution). The 35% hydrogen peroxide solution achieved a 6-log kill of MRSA after 30 minutes and 20 minutes for G. stearothermophilus.
The test involved distributing hydrogen peroxide at different concentrations (5%, 10% and 35%) in an 80 m3 sealed and environmentally controlled room. The MRSA and G. stearothermophilus 6-log biological indicators were placed in the enclosure to measure bioburden reduction.
The three cycles ran identically. The hydrogen peroxide was vaporised within the room for 40 minutes and left to dwell for an additional 200 minutes. During the first 120 minutes of the process, biological indicators were collected every 10 minutes in order to control log reduction.