The Sporicidal Activity Of Ethylene Oxide As Measured By The A.O.A.C. Sporicide Test
About: This article is published in Journal of AOAC International.The article was published on 1956-05-01. It has received 7 citations till now. The article focuses on the topics: Ethylene oxide.
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TL;DR: A survey of the literature that had potential application to the inactivation of B. anthracis spores was conducted and a tabular summary of the results is provided.
Abstract: After the intentional release of Bacillus anthracis through the U.S. Postal Service in the fall of 2001, many environments were contaminated with B. anthracis spores, and frequent inquiries were made regarding the science of destroying these spores. We conducted a survey of the lit- erature that had potential application to the inactivation of B. anthracis spores. This article provides a tabular sum- mary of the results. consistent between experiments, but each experiment pro- vides some specific information of value. Early studies that lack quantitative data are not included. A number of the cited studies address Bacillus species other than B. anthracis. We include these for information, with the caveat that surrogates do not always predict the behavior of the target species. Furthermore, the results from labora- tory experiments do not specifically address questions regarding the best methods for inactivating spores on dif- ferent materials such as mail, carpet, other porous objects, food, or water. Transfer of these sporicidal methods from the laboratory to a building has not yet been tested; how- ever, the known laboratory results are a logical place to start when considering the decontamination of a building. Decontamination is defined as the irreversible inactiva- tion of infectious agents so that an area is rendered safe. However, decontamination may not eliminate bacterial spores. Sterilization is the complete destruction or elimina- tion of microbial viability, including spores (3). The experiments described provide a logical starting point for future experiments and decontamination strate- gies in the event of anthrax bioterrorism. Our intent is not to provide a comparative evaluation or recommendations for decontamination but rather to summarize the quantita- tive published results and provide a useful reference. Review
187 citations
TL;DR: In this article, the presence of organic matter increases the percentage of cells that become resistant to ethylene oxide after dehydration, which is produced by exposing cells to a vacuum or a chemically desiccated atmosphere.
Abstract: Bacterial cells dehydrated beyond a critical point no longer react uniformly to ethylene oxide sterilization. The percentage of cells resistant to the lethal effect of ethylene oxide after desiccation is often as small as 0.1 to 0.001%. However, 5% resistant cells were observed with one type of microorganism dried in broth. The presence of organic matter increases the percentage of cells that become resistant to ethylene oxide after dehydration. The phenomenon is produced by exposing cells to a vacuum or a chemically desiccated atmosphere. It is not a permanent change, because the resistant cells rapidly become susceptible if wetted with water. On the other hand, mere exposure to a high relative humidity (RH), i.e., 75 to 98%, after desiccation requires 6 and 4 days, respectively, to overcome this resistance. Moisture studies showed that there is less water in bacterial cells that have been desiccated and then equilibrated to successively high RH values up to 100% RH, than in cells that have not been desiccated, but allowed to dry naturally until equilibrated to the same RH values.
51 citations
TL;DR: The relationships of reaction temperature and concentration of gaseous ethylene oxide to the time required for inactivation of air-dried Bacillus subtilis var.
Abstract: The relationships of reaction temperature and concentration of gaseous ethylene oxide to the time required for inactivation of air-dried Bacillus subtilis var. niger spores are more complex than previously reported. A plot of temperature vs. the logarithm of "thermochemical death time" (TCDT) resulted in a straight line between 18 and 57 C for systems of "high" ethylene oxide concentration. The TCDT values were independent of ethylene oxide concentrations above certain temperature-dependent limits. A given ethylene oxide concentration produced a TCDT curve identical in the upper temperature regions with that for higher concentrations. As the temperature was lowered beyond a critical point, this curve diverged from that for higher concentrations, as a straight line of lesser slope. Thus, a series of curves exists for a range of ethylene oxide concentrations. They are characterized by two segments, both logarithmic, intersecting at a critical temperature for each concentration. The intersecting point is at a temperature inversely related to the ethylene oxide gas concentration. The temperature quotient for the high temperature segments of all systems was 1.8. This value was characteristic for ethylene oxide concentrations of 440 and 880 mg/liter at temperatures above 40.6 and 33.4 C, respectively. Below these critical temperatures, the Q(10) values for the respective systems were 3.2 and 2.3.
32 citations
TL;DR: Results demonstrated pseudo first order behaviour of spore inactivation kinetics, and nanosized titania exhibited superior in activation kinetics on par with large sized titania.
20 citations
TL;DR: In 2001, envelopes containing virulent Bacillus anthracis spores were placed into the U.S. mail, resulting in contamination of mail processing and distribution facilities and office buildings as mentioned in this paper.
Abstract: In 2001, envelopes containing virulent Bacillus anthracis spores were placed into the U.S. mail, resulting in contamination of mail processing and distribution facilities and office buildings. Thes...
20 citations
Cites background from "The Sporicidal Activity Of Ethylene..."
...anthracis spores were completely inactivated at 60 minutes of exposure to ethylene oxide in which ethylene oxide appeared more effective in dry air compared to wet air (Friedl et al., 1956)....
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...The testing demonstrated that B. anthracis spores were completely inactivated at 60 minutes of exposure to ethylene oxide in which ethylene oxide appeared more effective in dry air compared to wet air (Friedl et al., 1956)....
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...A study conducted by Friedl et al. (1956) evaluated the sporicidal activity of ethylene oxide against B. anthracis spores following the AOAC sporicidal test....
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