Abstract
The ability to safely and reproducibly decontaminate enclosed areas like isolators and rooms is an important consideration to many industrial, research, and healthcare facilities. Traditionally, formaldehyde has been used, but safety and efficacy concerns have highlighted the need for alternative methods. Vaporized Hydrogen Peroxide, as used in STERIS Corporation's VHP® Technology, is a dry gaseous method that has been used as a reliable alternative for aseptic processing isolators and more recently for room/facility decontamination. In this report the antimicrobial efficacy of VHP Technology has been studied under worst-case test conditions, including the presence of contaminating soils which may be present under certain applications. Geo-bacillus stearothermophilus spores were verified as being the most resistant organism to the fumigation process while paper was identified as the most resistant material. Efficacy was then verified in the presence of 10% and 50% whole blood, as representative soils to ensure fumigant penetration. Typical VHP fumigation processes in rigid and flexible-walled isolators showed a ≥ 6 log10 reduction under these worst-case test conditions. Like other biocides, the microbiocidal activity of vaporized hydrogen peroxide is affected by the presence of soil, but these results confirm that VHP Technology can decontaminate under soiled conditions within a routine decontamination process.