Science Inventory

The Use of Ozone Gas for the Inactivation of Bacillus anthracis and Bacillus subtilis Spores on Building Materials

Citation:

Wood, Joe, M. Wendling, W. Richter, AND J. Rogers. The Use of Ozone Gas for the Inactivation of Bacillus anthracis and Bacillus subtilis Spores on Building Materials. Peter Setlow (ed.), PLOS ONE . Public Library of Science, San Francisco, CA, 15(5):e0233291, (2020). https://doi.org/10.1371/journal.pone.0233291

Impact/Purpose:

The recently published 2018 National Biodefense Strategy calls for the U.S. to manage the risk of biological incidents and, specifically, conduct research and development of technologies to enhance preparedness to support decontamination. These biological threats can be categorized as naturally occurring, accidental, or deliberate attacks such as the dissemination of virulent spores of Bacillus anthracis through the U.S. Postal Service. The present study supports the National Biodefense Strategy by verifying the efficacy of ozone gas as a decontaminant for inactivating B. anthracis spores deposited on various types of building materials.

Description:

A study was conducted to assess the efficacy of ozone gas in inactivating spores of both Bacillus anthracis and Bacillus subtilis inoculated onto six building materials (glass, wood, carpet, laminate, galvanized metal, and wallboard paper). Testing conditions consisted of ozone gas concentrations ranging from 7,000-12,000 parts per million (ppm), contact times from 4 to 12 h, and two relative humidity (RH) levels of 75 and 85%. Results showed that increasing the ozone concentration, contact time, and RH generally increased decontamination efficacy. The materials in which the highest decontamination efficacy was achieved for B. anthracis spores were wallboard paper, carpet, and wood with ≥ 6 log10 reduction (LR) occurring with 9,800 ppm ozone, 85 % RH, for 6 h. The laminate and galvanized metal materials were generally more difficult to decontaminate, requiring 12,000 ppm ozone, 85 % RH, and 9-12 h contact time to achieve ≥6 LR of B. anthracis. Lastly, there was no significant difference in decontamination efficacy between the two species.