Pilot-scale experimental and theoretical investigations into the thermal destruction of a Bacillus anthracis surrogate embedded in building decontamination residue bundles.

Bacillus anthracis (B. anthracis) spores were released through the U.S. mail system in 2001, highlighting the need to develop efficacious methods of decontaminating and disposing of materials contaminated with biological agents. Incineration of building decontamination residue is a disposal option for such material, although the complete inactivation of bacterial spores via this technique is not a certainty. Tests revealed that under some circumstances, Geobacillus stearothermophilus (G. stearothermophilus; a surrogate for B. anthracis) spores embedded in building materials remained active after 35 min in a pilot-scale incinerator and survived with internal material bundle temperatures reaching over 500 degrees C. A model was also developed to predict survival of a bacterial spore population undergoing thermal treatment in an incinerator using the thermal destruction kinetic parameters obtained in a laboratory setting. The results of the pilot-scale incinerator experiments are compared to model predictions to assess the accuracy of the model.