Disinfection efficacy of peroxyacetic acid against bacterial spores

Peracetic acid (PAA) is an emerging disinfectant known to be highly effective against various microorganisms. However, the capability of PAA to eliminate spores under different conditions and its application in liquid and gaseous forms remain unclear. Here, we aimed to develop a stabilized single-composite PAA and evaluate its disinfection efficacy in both liquid and gaseous form against suspended or surface-coated spores under varying temperature and humidity conditions. The results showed that PAA is a highly effective sporicide, with efficacy influenced by lower temperatures and humidity. Both gaseous (vapor and fog) and liquid forms showed strong sporicidal activity, with the fog (droplet) requiring less consumption than the vapor (converted into gas by heating). Our study showed that at high humidity (68 ± 2 %), 90 mg·m⁻³ vapor and 10 mg·m^-³ fog achieved a 6-log reduction on cloth within 90 and 120 min, respectively. At lower humidity (55 ± 2 %), 100 mg·m⁻³ vapor and 10 mg·m^-³ fog achieved lower reductions at 2-log and 0.7-log, respectively, both within 120 min. In conclusion, this study provides a comprehensive evaluation of the sporicidal efficacy of PAA under various conditions, highlighting its potential in aerosol droplet disinfection applications.