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Choi YW, Sunderman MM, McCauley MW, Richter WR, Willenberg ZJ, Wood J, Serre S, Mickelsen L, Willison S, Rupert R, Muñiz-Ortiz JG, Casey S, Calfee MW. Decontamination of Bacillus Spores with Formaldehyde Vapor under Varied Environmental Conditions. APPLIED BIOSAFETY 2021; 26:139-53. [PMID: 32982605 PMCID: PMC7511015 DOI: 10.1089/apb.21.926975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Introduction This study investigated formaldehyde decontamination efficacy against dried Bacillus spores on porous and non-porous test surfaces, under various environmental conditions. This knowledge will help responders determine effective formaldehyde exposure parameters to decontaminate affected spaces following a biological agent release. Methods Prescribed masses of paraformaldehyde or formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor within a bench-scale test chamber. Adsorbent cartridges were used to measure formaldehyde vapor concentrations in the chamber at pre-determined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. Spores of Bacillus globigii, Bacillus thuringiensis, and Bacillus anthracis were inoculated and dried onto porous bare pine wood and non-porous painted concrete material coupons. A series of tests was conducted where temperature, relative humidity, and formaldehyde concentration were varied, to determine treatment efficacy outside of conditions where this decontaminant is well-characterized (laboratory temperature and humidity and 12 mg/L theoretical formaldehyde vapor concentration) to predict decontamination efficacy in applications that may arise following a biological incident. Results Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations collected in the ambient temperature trials (approximately 22°C). Generally, decontamination efficacy on wood was lower for all three spore types compared with painted concrete. Also, higher recoveries resulted from painted concrete compared to wood, consistent with historical data on these materials. The highest decontamination efficacies were observed on the spores subjected to the longest exposures (48 hours) on both materials, with efficacies that gradually decreased with shorter exposures. Adsorption or absorption of the formaldehyde vapor may have been a factor, especially during the low temperature trials, resulting in less available formaldehyde in the air when measured. Conclusion Environmental conditions affect formaldehyde concentrations in the air and thereby affect decontamination efficacy. Efficacy is also impacted by the material with which the contaminants are in contact.
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Affiliation(s)
| | | | | | | | | | - Joseph Wood
- US Environmental Protection Agency, TW Alexander Drive, Research Triangle Park, NC, USA
| | - Shannon Serre
- US Environmental Protection Agency, TW Alexander Drive, Research Triangle Park, NC, USA
| | - Leroy Mickelsen
- US Environmental Protection Agency, TW Alexander Drive, Research Triangle Park, NC, USA
| | | | - Rich Rupert
- US Environmental Protection Agency, Region 3, Philadelphia, PA
| | | | - Sara Casey
- United Kingdom, Department for Environment, Food and Rural Affairs, CBRN Recovery Team, Stafford, England
| | - M Worth Calfee
- US Environmental Protection Agency, TW Alexander Drive, Research Triangle Park, NC, USA
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Choi YW, Sunderman MM, McCauley MW, Richter WR, Willenberg ZJ, Wood J, Serre S, Mickelsen L, Willison S, Rupert R, Ortiz JGM, Casey S, Calfee MW. Decontamination of Bacillus Spores with Formaldehyde Vapor Under Varied Environmental Conditions. APPLIED BIOSAFETY 2020. [DOI: 10.1177/1535676020926975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Introduction: This effort investigated formaldehyde vapor characteristics under various environmental conditions by the analyses of air samples collected over a time-course. This knowledge will help responders achieve desired formaldehyde exposure parameters for decontamination of affected spaces after a biological contamination incident. Methods: Prescribed masses of paraformaldehyde and formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor. Adsorbent cartridges were used to collect air samples from the test chamber at predetermined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. In addition, material demand for the formaldehyde was evaluated by inclusion of arrays of Plexiglas panels in the test chamber to determine the effect of varied surface areas within the test chamber. Temperature was controlled with a circulating water bath connected to a radiator and fan inside the chamber. Relative humidity was controlled with humidity fixed-point salt solutions and water vapor generated from evaporated water. Results: Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations in the ambient temperature trials (approximately 22°C). The addition of clear Plexiglas panels to increase the surface area of the test chamber interior resulted in appreciable decreases of formaldehyde air concentration when compared to an empty test chamber. Conclusion: This work has shown that environmental variables and surface-to-volume ratios in the decontaminated space may affect the availability of formaldehyde in the air and, therefore, may affect decontamination effectiveness.
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Affiliation(s)
| | | | | | | | | | - Joseph Wood
- US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Shannon Serre
- US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Leroy Mickelsen
- US Environmental Protection Agency, Research Triangle Park, NC, USA
| | | | - Rich Rupert
- US Environmental Protection Agency, Region 3, Philadelphia, PA, USA
| | | | - Sara Casey
- Department for Environment, Food and Rural Affairs, CBRN Recovery Team, Stafford, UK
| | - M. Worth Calfee
- US Environmental Protection Agency, Research Triangle Park, NC, USA
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Choi YW, Sunderman MM, McCauley MW, Richter WR, Willenberg ZJ, Wood J, Serre S, Mickelsen L, Willison S, Rupert R, Ortiz JGM, Casey S, Calfee MW. Formaldehyde Vapor Characteristics in Varied Decontamination Environments. APPLIED BIOSAFETY 2020. [DOI: 10.1177/1535676020926968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction: This effort investigated formaldehyde vapor characteristics under various environmental conditions by the analyses of air samples collected over a time-course. This knowledge will help responders achieve desired formaldehyde exposure parameters for decontamination of affected spaces after a biological contamination incident. Methods: Prescribed masses of paraformaldehyde and formalin were sublimated or evaporated, respectively, to generate formaldehyde vapor. Adsorbent cartridges were used to collect air samples from the test chamber at predetermined times. A validated method was used to extract the cartridges and analyze for formaldehyde via liquid chromatography. In addition, material demand for the formaldehyde was evaluated by inclusion of arrays of Plexiglas panels in the test chamber to determine the impact of varied surface areas within the test chamber. Temperature was controlled with a circulating water bath connected to a radiator and fan inside the chamber. Relative humidity was controlled with humidity fixed-point salt solutions and water vapor generated from evaporated water. Results: Low temperature trials (approximately 10°C) resulted in decreased formaldehyde air concentrations throughout the 48-hour time-course when compared with formaldehyde concentrations in the ambient temperature trials (approximately 22°C). The addition of clear Plexiglas panels to increase the surface area of the test chamber interior resulted in appreciable decreases of formaldehyde air concentration when compared to an empty test chamber. Conclusion: This work has shown that environmental variables and surface-to-volume ratios in the decontaminated space may affect the availability of formaldehyde in the air and, therefore, may affect decontamination effectiveness.
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Affiliation(s)
| | | | | | | | | | - Joseph Wood
- US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Shannon Serre
- US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Leroy Mickelsen
- US Environmental Protection Agency, Research Triangle Park, NC, USA
| | | | - Rich Rupert
- US Environmental Protection Agency, Region 3, Philadelphia, PA, USA
| | | | - Sara Casey
- Department for Environment, Food and Rural Affairs, CBRN Recovery Team, Stafford, UK
| | - M. Worth Calfee
- US Environmental Protection Agency, Research Triangle Park, NC, USA
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Stuart J, Chewins J, Tearle J. Comparing the Efficacy of Formaldehyde with Hydrogen Peroxide Fumigation on Infectious Bronchitis Virus. APPLIED BIOSAFETY 2020; 25:83-89. [PMID: 34191920 PMCID: PMC7307011 DOI: 10.1177/1535676020909998] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND The recent reclassification of formaldehyde as a presumed carcinogen prompted the investigation into the comparative efficacy of hydrogen peroxide as a fumigant in microbiological safety cabinets. INTRODUCTION The aim of the study was to quantify the biocidal efficacy of formaldehyde fumigation, including variables such as exposure time and concentration, and then to compare this to the biocidal efficacy achieved from a hydrogen peroxide vapor fumigation system. The study also investigated the ability of both fumigants to permeate the microbiological safety cabinet (MBSC), including the workspace, under the work tray, and after the HEPA filters. Furthermore, the effect of organic soiling on efficacy was also assessed. Infectious bronchitis virus (IBV) was used as the biological target to develop this study model. METHODS A model using IBV was developed to determine the efficacy of formaldehyde and hydrogen peroxide as fumigants. Virus was dried on stainless steel discs, and variables including concentration, time, protein soiling, and location within an MBSC were assessed. RESULTS It was demonstrated that formaldehyde fumigation could achieve a 6-log reduction in the titer of the virus throughout the cabinet, and high protein soiling in the presentation did not affect efficacy. Appropriate cycle parameters for the hydrogen peroxide system were developed, and when challenged with IBV, it was shown that vaporized hydrogen peroxide could achieve an equal 6-log titer reduction as formaldehyde within the cabinet workspace and overcome the presence of soiling. CONCLUSION Hydrogen peroxide was demonstrated to be a viable alternative to formaldehyde under most situations tested. However, the hydrogen peroxide system did not achieve an equal titer reduction above the cabinet's first HEPA filter using the cabinet workspace cycle, and further optimization of the hydrogen peroxide cycle parameters, including pulsing of the cabinet fans, may be required to achieve this.
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Pottage T, Lewis S, Lansley A, Fraser S, Hendon-Dunn C, Bacon J, Ngabo D, Parks SR, Bennett AM. Hazard Group 3 agent decontamination using hydrogen peroxide vapour in a class III microbiological safety cabinet. J Appl Microbiol 2019; 128:116-123. [PMID: 31559683 DOI: 10.1111/jam.14461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/09/2019] [Accepted: 09/23/2019] [Indexed: 11/30/2022]
Abstract
AIMS This study investigated the efficacy of hydrogen peroxide vapour (HPV) at inactivating hazard group 3 bacteria that have been presented dried from their growth medium to present a realistic challenge. METHODS AND RESULTS Hydrogen peroxide vapour technology (Bioquell) was used to decontaminate a class III microbiological safety cabinet containing biological indicators (BIs) made by drying standard working suspensions of the following agents: Bacillus anthracis (Ames) spores, Brucella abortus (strain S99), Burkholderia pseudomallei (NCTC 12939), Escherichia coli O157 ST11 (NCTC 12079), Mycobacterium tuberculosis (strain H37Rv) and Yersinia pestis (strain CO92) on stainless steel coupons. Extended cycles were used to expose the agents for 90 min. The HPV cycle completely inactivated B. anthracis spores, B. abortus, B. pseudomallei, E. coli O157 and Y. pestis when BIs were processed using quantitative and qualitative methods. Whilst M. tuberculosis was not completely inactivated, it was reduced by 4 log10 from a starting concentration of 106 colony-forming units. CONCLUSIONS This study demonstrates that HPV is able to inactivate a range of HG3 agents at high concentrations with associated organic matter, but M. tuberculosis showed increased resistance to the process. SIGNIFICANCE AND IMPACT OF THE STUDY This publication demonstrates that HPV can inactivate HG3 agents that have an organic load associated with them. It also shows that M. tuberculosis has higher resistance to HPV than other agents. This shows that an appropriate BI to represent the agent of interest should be chosen to demonstrate a decontamination is successful.
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Affiliation(s)
- T Pottage
- Biosafety, Air and Water Microbiology Group, National Infection Service, Public Health England, Salisbury, UK
| | - S Lewis
- Novel and Dangerous Pathogens Training, National Infection Service, Public Health England, Salisbury, UK
| | - A Lansley
- Novel and Dangerous Pathogens Training, National Infection Service, Public Health England, Salisbury, UK
| | - S Fraser
- Novel and Dangerous Pathogens Training, National Infection Service, Public Health England, Salisbury, UK
| | - C Hendon-Dunn
- TB Research Group, National Infection Service, Public Health England, Salisbury, UK
| | - J Bacon
- TB Research Group, National Infection Service, Public Health England, Salisbury, UK
| | - D Ngabo
- Medical Interventions Group, National Infection Service, Public Health England, Salisbury, UK
| | - S R Parks
- Biosafety, Air and Water Microbiology Group, National Infection Service, Public Health England, Salisbury, UK
| | - A M Bennett
- Biosafety, Air and Water Microbiology Group, National Infection Service, Public Health England, Salisbury, UK
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Wood JP, Adrion AC. Review of Decontamination Techniques for the Inactivation of Bacillus anthracis and Other Spore-Forming Bacteria Associated with Building or Outdoor Materials. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4045-4062. [PMID: 30901213 PMCID: PMC6547374 DOI: 10.1021/acs.est.8b05274] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Since the intentional release of Bacillus anthracis spores through the U.S. Postal Service in the fall of 2001, research and development related to decontamination for this biological agent have increased substantially. This review synthesizes the advances made relative to B. anthracis spore decontamination science and technology since approximately 2002, referencing the open scientific literature and publicly available, well-documented scientific reports. In the process of conducting this review, scientific knowledge gaps have also been identified. This review focuses primarily on techniques that are commercially available and that could potentially be used in the large-scale decontamination of buildings and other structures, as well as outdoor environments. Since 2002, the body of scientific data related to decontamination and microbial sterilization has grown substantially, especially in terms of quantifying decontamination efficacy as a function of several factors. Specifically, progress has been made in understanding how decontaminant chemistry, the materials the microorganisms are associated with, environmental factors, and microbiological methods quantitatively impact spore inactivation. While advancement has been made in the past 15 years to further the state of the science in the inactivation of bacterial spores in a decontamination scenario, further research is warranted to close the scientific gaps that remain.
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Affiliation(s)
- Joseph P. Wood
- United States Environmental Protection Agency, Offce of Research and Development, National Homeland Security Research Center, Research Triangle Park, North Carolina United States
- Corresponding Author: Phone: (919) 541-5029;
| | - Alden Charles Adrion
- United States Environmental Protection Agency, Offce of Research and Development, National Homeland Security Research Center, Research Triangle Park, North Carolina United States
- Oak Ridge Institute for Science and Education Postdoctoral Fellow, Oak Ridge, Tennessee 37830, United States
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