Decontamination of Geobacillus Stearothermophilus using the Arca Aerosolized Hydrogen Peroxide decontamination system

In response to the limited supply of personal protective equipment during the pandemic caused by SARS-CoV-2, recent studies demonstrate that gaseous H2O2 is an effective decontaminant of N95 filtering facepiece respirators to enable reuse of these items in a clinical setting. This paper evaluates the efficacy of the Arca Aerosolized Hydrogen Peroxide Decontamination System (Arca), a novel aerosolized H2O2 decontamination system, using biologic indicator testing.

The Arca produces and circulates H2O2 aerosol inside of a sealed stainless steel chamber. The Arca's decontamination efficacy was evaluated in 8 decontamination trials with 2 H2O2 concentrations (3% and 12%) and 4 decontamination cycle durations (45, 60, 90, and 120 minutes). Efficacy was evaluated by testing: 1) the concentration in parts per million (ppm) of H2O2 produced inside the chamber and the concentration in ppm of H2O2 vented from the chamber, and 2) the decontamination of Mesa Biologic Indicator filter strips (BI) inoculated with Geobacillus Stearothermophilus. Control tests were conducted by submerging BI strips in 3mL of 3% and 12% H2O2 for 120 minutes (negative controls) and by not exposing one BI strip to H2O2 (positive control).

Greater than 5000 ppm of H2O2 was detected on the concentration strips inside the chamber for each of the eight decontamination trials. No vented H2O2 was detected on the external concentration strips after any decontamination trial. No growth was observed for any of the negative controls after seven days. The positive control was positive for growth.

The Arca Aerosolized Hydrogen Peroxide Decontamination System is effective at decontaminating bacterial G. Stearothermophilus at a cycle time of 45 minutes utilizing 6mL of 3% H2O2 solution.