Hydrogen peroxide fogging of isolation gowns: Disinfection efficacy and VOC emissions

Isolation gowns constitute the majority of the PPE waste generated daily worldwide. Disinfection with reuse that is easily reproducible without the need for expensive equipment or trained personnel is needed. This study evaluated the use of 9% hydrogen peroxide fogging using a commercially available fogger on isolation gowns heavily inoculated in the torso region of the gown with Staphylococcus epidermidis and Escherichia coli to challenge efficacy. Cultures were obtained on isolation gowns immediately after inoculation from both the interior as well as the exterior of the gowns before disinfection. Gowns were then fogged with 9% hydrogen peroxide (HP) for 1 min and 30sec. A four-hour trying time was instituted, and gowns were cultured from the torso region again. All cultures were incubated at 37 °C for 72 hours. CFU at 48- and 72-hours post-incubation were obtained. Safety of this methodology was studied by evaluating Total Volatile Organic Compounds (TVOCs) as a VOC index (1-500) as well as in parts per million (PPM) generated during HP fogging of gowns, aiming to determine whether the use of vacuum-aeration (VA) led to an improvement in VOCs generated. Results indicate that fogging with HP was effective at reducing S. epidermidis and E. coli as measured by CFU (100% reduction at 72 hours for both organisms). VOC index and PPM were greater without VA than with VA. The maximum Δ(IndexBC) (191) and Δ (PPMBC) (0.301) occurred at 90 minutes and then fell to between 156 and 187 for Δ (IndexBC) and 0.202 and 0.253 for Δ (PPMBC). This corresponded to 82% (156/191) and 98% (187/191) of the maximum VOC index and 67% (0.202/0.301) and 84% (0.253/0.301) of the maximum PPM without VA. Our results indicate that HP fogging may be a viable option for disinfection and reuse of single use isolation gowns and VA may be a valuable additional step in improving air quality during the process.