Fumigation of a Laboratory-scale HVAC System with Hydrogen Peroxide for Decontamination Following a Biological Contamination Incident

Authors

K. M. Meyer, Oak Ridge Institute for Science and Education, United States Environmental Protection Agency, Office of Research and Development, National Homeland Security Research Center
M. W. Calfee, United States Environmental Protection Agency, Office of Research and Development, National Homeland Security Research CenterFollow
J. P. Wood, United States Environmental Protection Agency, Office of Research and Development, National Homeland Security Research Center
L. Michelsen, United States Environmental Protection Agency, Office of Emergency Management, Research Triangle Park
B. Attwood, United States Environmental Protection Agency, Office of Research and Development, National Homeland Security Research Center, Research Triangle Park
M. Clayton, Arcadis G&M, Durham, North Carolina
A. Touati, Arcadis G&M, Durham, North Carolina
R. Delafield, Arcadis G&M, Durham, North Carolina

Document Type

Article

Date of this Version

2013

Citation

Journal of Applied Microbiology (2013) 116: 533--541

doi: 10.1111/jam.12404

Comments

United States government work

Abstract

Aims

To evaluate hydrogen peroxide vapor (H₂O₂) for its ability to inactivate Bacillus spores within a laboratory-scale heating, ventilation and air-conditioning (HVAC) duct system.

Methods and Results

Experiments were conducted in a closed-loop duct system, constructed of either internally lined or unlined galvanized metal. Bacterial spores were aerosol-deposited onto 18-mm-diameter test material coupons and strategically placed at several locations within the duct environment. Various concentrations of H₂O₂ and exposure times were evaluated to determine the sporicidal efficacy and minimum exposure needed for decontamination. For the unlined duct, high variability was observed in the recovery of spores between sample locations, likely due to complex, unpredictable flow patterns within the ducts. In comparison, the lined duct exhibited a significant desorption of the H₂O₂ following the fumigant dwell period and thus resulted in complete decontamination at all sampling locations.

Conclusions

These findings suggest that decontamination of Bacillus spore-contaminated unlined HVAC ducts by hydrogen peroxide fumigation may require more stringent conditions (higher concentrations, longer dwell duration) than internally insulated ductwork.

Significance and Impact of the Study

These data may help emergency responders when developing remediation plans during building decontamination.