Science Inventory

Passenger vehicle interior decontamination by low concentration hydrogen peroxide vapor following a wide area biological contamination incident

Citation:

Oudejans, L., W. Richter, M. Sunderman, W. Calfee, L. Mickelsen, K. Hofacre, P. Keyes, AND S. Lee. Passenger vehicle interior decontamination by low concentration hydrogen peroxide vapor following a wide area biological contamination incident. JOURNAL OF APPLIED MICROBIOLOGY. Blackwell Publishing, Malden, MA, 134(3):lxad039, (2023). https://doi.org/10.1093/jambio/lxad039

Impact/Purpose:

Following a wide area biological contamination event, many emergency or personal vehicles may become contaminated through direct event exposure or secondary exposure from cross-contamination. This would lead to many logistical challenges, including decontamination of large numbers of contaminated vehicles. EPA has developed a low-tech method of generating low concentration vaporous hydrogen peroxide which offers benefits of rapid deployment and scalability. This publication provides the results of the application of this low-tech approach against Bacillus atrophaeus spores (a B. anthracis surrogate) within the interior of a mid-sized vehicle. The results of this research will inform the EPA response community as well as other Federal, State, Tribal and Local agencies on the means to decontaminate the interior of vehicles that are contaminated with biological spores.

Description:

Rapid decontamination following a biological terror incident is paramount for the return of a city’s operations and economy to normalcy. An outdoor urban biological agent incident may require remediation of thousands of vehicles. In this research, the utilization of widely available equipment and chemicals to decontaminate vehicle interiors was evaluated using low concentration hydrogen peroxide (H2O2) vapor dispersed with a home humidifier. Efficacy of a vaporized 3% H2O2 solution against Bacillus anthracis surrogate Bacillus atrophaeus was evaluated for two liquid volumes of 3% H2O2, on/off vehicle HVAC operations, and at temperatures that ranged from 5 to 27 °C with a dwell time of six days.Decontamination efficacy increased when the 3% H2O2 liquid volume was doubled, increasing from 4-of-10 to 10-of-10 non-detects inside the cabin. Recirculating cabin air through the HVAC system during decontamination decreased efficacy to 6-of-10 non-detects while it did not improve efficacy on the cabin filter. A 6-log10 reduction in viable spores was achieved on the cabin filter after its removal and placement in the cabin during treatment. Recontamination was observed for tests when running the HVAC system after decontamination. Results from this study allow for informed decisions regarding the selection of appropriate and effective decontamination approaches for vehicle interiors.