The inactivation of bacillus subtilis spores at low concentrations of hydrogen peroxide vapour

Spores of the bacterium Bacillussubtilis were deposited onto the surface of membranes by a process of filtration and exposed to concentrations of hydrogen peroxide vapour between 10 and 90 mg/m3 (ppm) for times ranging from 1.5 to 48 h. The inactivation data obtained in this way was modelled using the Weibull, Series-Event and Baranyi inactivation models. The Weibull model provided the best fit, and its use was extended to previously published literature obtained at higher hydrogen peroxide concentrations to produce a correlation yielding D (decimal reduction value) values over a range from 10 to almost 4000 ppm.