scholarly journals Analysis of SteraMist ionized hydrogen peroxide technology in the sterilization of N95 respirators and other PPE

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Avilash K. Cramer ◽  
Deborah Plana ◽  
Helen Yang ◽  
Mary M. Carmack ◽  
Enze Tian ◽  
...  

AbstractThe COVID-19 pandemic has led to widespread shortages of personal protective equipment (PPE) for healthcare workers, including of N95 masks (filtering facepiece respirators; FFRs). These masks are intended for single use but their sterilization and subsequent reuse has the potential to substantially mitigate shortages. Here we investigate PPE sterilization using ionized hydrogen peroxide (iHP), generated by SteraMist equipment (TOMI; Frederick, MD), in a sealed environment chamber. The efficacy of sterilization by iHP was assessed using bacterial spores in biological indicator assemblies. After one or more iHP treatments, five models of N95 masks from three manufacturers were assessed for retention of function based on their ability to form an airtight seal (measured using a quantitative fit test) and filter aerosolized particles. Filtration testing was performed at a university lab and at a National Institute for Occupational Safety and Health (NIOSH) pre-certification laboratory. The data demonstrate that N95 masks sterilized using SteraMist iHP technology retain filtration efficiency up to ten cycles, the maximum number tested to date. A typical iHP environment chamber with a volume of ~ 80 m3 can treat ~ 7000 masks and other items (e.g. other PPE, iPADs), making this an effective approach for a busy medical center.

Author(s):  
Avilash K. Cramer ◽  
Deborah Plana ◽  
Helen Yang ◽  
Mary M. Carmack ◽  
Enze Tian ◽  
...  

AbstractObjectiveThe COVID-19 pandemic has led to widespread shortages of personal protective equipment (PPE) for healthcare workers, including filtering facepiece respirators (FFRs) such as N95 masks. These masks are normally intended for single use, but their sterilization and subsequent reuse could substantially mitigate a world-wide shortage.DesignQuality assurance.SettingA sealed environment chamber installed in the animal facility of an academic medical center.InterventionsOne to five sterilization cycles using ionized hydrogen peroxide (iHP), generated by SteraMist® equipment (TOMI; Frederick, MD).Main outcome measuresPersonal protective equipment, including five N95 mask models from three manufacturers, were evaluated for efficacy of sterilization following iHP treatment (measured with bacterial spores in standard biological indicator assemblies). Additionally, N95 masks were assessed for their ability to efficiently filter particles down to 0.3µm and for their ability to form an airtight seal using a quantitative fit test. Filtration efficiency was measured using ambient particulate matter at a university lab and an aerosolized NaCl challenge at a National Institute for Occupational Safety and Health (NIOSH) pre-certification laboratory.ResultsThe data demonstrate that N95 masks sterilized using SteraMist iHP technology retain function up to five cycles, the maximum number tested to date. Some but not all PPE could also be sterilized using an iHP environmental chamber, but pre-treatment with a handheld iHP generator was required for semi-enclosed surfaces such as respirator hoses.ConclusionsA typical iHP environment chamber with a volume of ~80 m3 can treat ~7000 masks per day, as well as other items of PPE, making this an effective approach for a busy medical center.


Author(s):  
Ebru Oral ◽  
Keith K. Wannomae ◽  
Rachel Connolly ◽  
Joseph Gardecki ◽  
Hui Min Leung ◽  
...  

There are a variety of methods routinely used in the sterilization of medical devices using hydrogen peroxide (H2O2) including vaporization, plasma generation and ionization. Many of these systems are used for sterilization and are validated for bioburden reduction using bacterial spores.Here, we explored the benefits of using vaporized H2O2 (VHP) treatment of N95 respirators for emergency decontamination and reuse to alleviate PPE shortages for healthcare workers in the COVID-19 emergency. The factors that are considered for the effective reuse of these respirators are the fit, the filter efficiency and the decontamination/disinfection level for SARS-CoV-2, which is the causative virus for COVID-19 and other organisms of concern in the hospital environment such as methicillin-resistant Staphylococcus aureus or Clostridium difficile. WE showed that the method did not affect fit or filter efficiency at least for one cycle and resulted in a >6 log reduction in bacterial spores and >3.8 log reduction in the infectious SARS-CoV2 load on N95 respirators.


Author(s):  
Robert J. Fischer ◽  
Dylan H. Morris ◽  
Neeltje van Doremalen ◽  
Shanda Sarchette ◽  
M. Jeremiah Matson ◽  
...  

The unprecedented pandemic of SARS-CoV-2 has created worldwide shortages of personal protective equipment, in particular respiratory protection such as N95 respirators. SARS-CoV-2 transmission is frequently occurring in hospital settings, with numerous reported cases of nosocomial transmission highlighting the vulnerability of healthcare workers. In general, N95 respirators are designed for single use prior to disposal. Here, we have analyzed four readily available and often used decontamination methods: UV, 70% ethanol, 70C heat and vaporized hydrogen peroxide for inactivation of SARS-CoV-2 on N95 respirators. Equally important we assessed the function of the N95 respirators after multiple wear and decontamination sessions.


Author(s):  
Robert J. Fischer ◽  
Dylan H. Morris ◽  
Neeltje van Doremalen ◽  
Shanda Sarchette ◽  
Jeremiah Matson ◽  
...  

The unprecedented pandemic of SARS-CoV-2 has created worldwide shortages of personal protective equipment, in particular respiratory protection such as N95 respirators. SARS-CoV-2 transmission is frequently occurring in hospital settings, with numerous reported cases of nosocomial transmission highlighting the vulnerability of healthcare workers. In general, N95 respirators are designed for single use prior to disposal. Several groups have addressed the potential for re-use of N95 respirators from a mechanical or from a decontamination perspective. Here, we analyzed four different decontamination methods – UV radiation (260 – 285 nm), 70ºC heat, 70% ethanol and vaporized hydrogen peroxide (VHP) – for their ability to reduce contamination with infectious SARS-CoV-2 and their effect on N95 respirator function.


Author(s):  
Ebru Oral ◽  
Keith K. Wannomae ◽  
Rachel L. Connolly ◽  
Joseph A. Gardecki ◽  
Hui Min Leung ◽  
...  

Decontamination of N95 respirators has become critical to alleviate PPE shortages for healthcare workers in the current COVID-19 emergency. The factors that are considered for the effective reuse of these masks are the fit, filter efficiency and decontamination/disinfection level both for SARS-CoV-2, which is the causative virus for COVID-19, and for other organisms of concern in the hospital environment such as Staphylococcus aureus or Clostridium difficile.In its guidance entitled ‘Recommendations for Sponsors Requesting EUAs for Decontamination and Bioburden Reduction Systems for Surgical Masks and Respirators During the Coronavirus Disease 2019 (COVID19) Public Health Emergency’ (May 2020)[1], the FDA recommends a 6-log10 reduction in either the most resistant bacterial spores for the system or in a mycobacterium species to authorize the use of a decontamination method of N95 respirators for single or multiple users. While the goal is primarily inactivation against SARS-CoV-2, testing of decontamination methods against the virus may not always be available. For decontamination methods considered for only single users, the recommendation is a 6-log10 reduction in the infective virus concentration of 3 non-enveloped viruses or in the concentration of two Gram (+) and two Gram (-) bacteria. Based on these recommendations, we explored the efficacy of vaporized H2O2 (VHP) treatment of N95 respirators against surrogate viruses covering a wide range of disinfection resistance for emergency decontamination and reuse to alleviate PPE shortages for healthcare workers in the COVID-19 emergency.


Author(s):  
Prima Ardiansah Surya ◽  
Marsheila Harvy Mustikaningtyas ◽  
Sacharissa Zerlina Tsarwah Thirafi ◽  
Afika Danedea Pramitha ◽  
Laksita Taffara Mahdy ◽  
...  

Introduction: The pandemic of COVID-19 has major effects, particularly on hospitals and health workers. At the beginning of March, more than 3,300 health workers have beencontracted with COVID-19 as reported by China's National Health Commission. Twenty percent of healthcare workers in Italy have also also infected and some died. To minimize the risk of transmission to health workers, knowledge of the risk factors that influence the transmission is needed. Thus, this study aims to determine risk factors related to occupational safety and health for healthcare workers during the COVID-19 pandemic. Methods: The literature was searched on Pubmed, Google Scholar, WHO, and the Ministry of Health instruments were implemented. 8 relevant studies were reviewed. Results: According to the analysis results of several studies, the use of PPE that is less consistent and not suitable with the risk of exposure will increase the risk of infection. The risk of infection is also increased by poor hand hygiene. According to the Kaplan-Meier curve, the working duration of ≥ 15 hours will increase the risk of infection. The risk of infection also exists for health workers who carry out risky procedures that generate airborne particles such as resuscitation, as well as environmental factors such as negative pressure rooms and traffic control bundling. Conclusion: Risk factors related to occupational health and safety during this COVID-19 pandemic for healthcare staff are: compliance with the use of PPE, hand hygiene, working hours duration, risky procedures, and environmental factors.Keywords: healthcare workers, occupational safety, COVID-19, personal protective equipment


1999 ◽  
Vol 20 (4) ◽  
pp. 237-241 ◽  
Author(s):  
Tiina A. Reponen ◽  
Zheng Wang ◽  
Klaus Willeke ◽  
Sergey A. Grinshpun

AbstractObjectives:The overall aim of this study was to investigate the survival and possible growth of Mycobacterium tuberculosis simulant bacteria on respirator filters.Methods:Mycobacterium smegmatis was used as a biochemical simulant for M tuberculosis. Bacterial survival was tested on National Institute for Occupational Safety and Health-certified N95 respirators from three manufacturers. The first experiments simulated one-time respirator use and subsequent storage for 1 to 9 days under ideal conditions for the growth of mycobacteria: 37°C and 85% relative humidity. The bacteria were loaded on the respirator filters under three different nutritional conditions: in the absence of nutrients; in the presence of human saliva (simulating conditions when the respirator is worn); and in the presence of nutrient broth (for ideal growth potential). The subsequent experiments simulated respirator wear for 2 hours under medium workload conditions at a breathing rate of 56 L/min.Results:It was found that M smegmatis did not grow on the tested respirators, even when the respirators were stored at temperature, humidity, and nutrition conditions most favorable for microbial growth. However, these bacteria could survive on respirators for up to 3 days during storage. The culturability of M smegmatis was not affected by airflow that simulated the breathing rate associated with medium work-load conditions for 2 hours.Conclusions:This study shows that M tuberculosis surrogate bacteria collected on a respirator are not able to grow and are able to survive only in ideal (ie, not clinically relevant) conditions. Based on these experiments, we conclude that M tuberculosis is unlikely ever to become an infectious problem in the air again, once it is removed by a respirator.


2021 ◽  
pp. jim-2021-001908
Author(s):  
Mengyi Zha ◽  
Jude Alsarraj ◽  
Brandon Bunch ◽  
David Venzon

Substandard use of N95 masks, sometimes combined with dry heat decontamination, lacks safety data. We evaluated the impact of these practices on the fitness of N95 masks. This is a non-human subject research conducted from July to October 2020. 155 masks were used by 12 healthcare workers during 10-hour shifts. Masks were collected at the end of the shift and if the number of donnings/doffings was less than five (‘modified extended use’, ME) or whenever this number reached five (‘limited reuse’, LR), per the recommendation of the Centers for Disease Control and Prevention. Masks that passed an Occupational Safety and Health Administration qualitative fit test underwent a cycle (30 min, 75°C) of dry heat decontamination. After use, 84% (95% CI 77% to 90%) of the masks fit the users, 85% (95% CI 73% to 93%) in ME and 83% (95% CI 73% to 90%) in LR. After dry heat, 86% of the fitted masks (95% CI 78% to 91%) still fit, 93% (95% CI 80% to 98%) in ME and 82% (95% CI 70% to 89%) in LR. If a fit test was not done before decontamination, 72% (95% CI 64% to 79%) of the masks would fit, 79% (95% CI 66% to 88%) in ME and 68% (95% CI 57% to 77%) in LR. Common substandard use preserves fitness of N95 masks up to 85%. One cycle of dry heat decontamination preserves fitness of N95 masks up to 93% when donned/doffed less than five times and fitness is ensured before decontamination. If a fit test is not performed beforehand, dry heat decontamination cannot preserve the fitness of used N95 masks above 80%.


2021 ◽  
Author(s):  
liran shechtman ◽  
Gal ben-Haim ◽  
ilan ben-zvi ◽  
Laurence steel ◽  
Avinoah Ironi ◽  
...  

Abstract BackgroundSince the emergence of coronavirus disease, health care professionals in high-risk environments are mandated to wear N95 respirators for prolonged periods. The effect of this prolonged use on cardio-respiratory variables and gas-exchange is poorly defined. The objective of the current study was to determine gas exchange abnormalities and physiological changes among healthcare workers during a 4-hour emergency department (ED) shift while wearing the N95 respirator.MethodsThis was a single-center prospective observational study that consisted of medical staff working at the Sheba Medical Center ED. Physiological effects and gas exchange variables were obtained under normal breathing conditions and after 4-hour shifts while continuously wearing an N95 respirator. Comparisons of paired measurements were performed using a non-parametric Wilcoxon matched-pairs signed-rank test.ResultsForty-one subjects were included in the study. Prolonged N95 respirator use was associated with a significant decline in plasma pH [7.35mmHg vs. 7.34mmHg, P=0.02], PvO2 [23.2 mmHg vs. 18.6 mmHg, P<0.001] and a concurrent increase in EtCO2 [32.5mmHg vs. 38.5mmHg, p<0.0001]. PvCO2 and bicarbonate levels did not differ. No significant change was observed for heart rate or oxygen saturation. ConclusionUsing an N95 respirator for prolonged periods by healthcare professionals may provoke changes in gas exchange. The clinical significance of these changes in terms of symptoms or longer-term health status is unknown and remains to be determined.


Author(s):  
Ebru Oral ◽  
Keith K Wannomae ◽  
Dmitry Gil ◽  
Rachel Connolly ◽  
Joseph A Gardecki ◽  
...  

Decontamination of N95 respirators has become critical to alleviate PPE shortages for healthcare workers in the current COVID-19 emergency. The factors that are considered for the effective reuse of these masks are the fit, filter efficiency and decontamination/disinfection level both for SARS-CoV2, which is the causative virus for COVID-19, and for other organisms of concern in the hospital environment such as Staphylococcus aureus or Clostridium difficile.The efficacy of inactivation or eradication against various pathogens should be evaluated thoroughly to understand the level of afforded disinfection. Methods commonly used in the sterilization of medical devices such as ionizing radiation, vaporized hydrogen peroxide, and ethylene oxide can provide a high level of disinfection, defined as a 6 log10 reduction, against bacterial spores, considered the most resistant microorganisms. CDC guidance on the decontamination and reuse of N95s also includes the use of moist heat (60°C, 80% relative humidity, 15-30 min) as a possible recommendation based on literature showing preservation of fit efficiency and inactivation of H1N1 on spiked masks.Here, we explored the efficacy of using moist heat under these conditions as a decontamination method for an N95 respirator (3M 1860S, St. Paul, MN) against various pathogens with different resistance; enveloped RNA viruses, Gram (+/-) bacteria, and non-enveloped viruses.


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