Ultraviolet germicidal irradiation: Possible method for respirator disinfection to facilitate reuse during the COVID-19 pandemic

Hamzavi, Iltefat; Lyons, Alexis B.; Kohli, Indermeet; Narla, Shanthi; Parks-Miller, Angela; Gelfand, Joel M.; Lim, Henry W.; Ozog, David M.

doi:10.1016/j.jaad.2020.03.085

Cited by 146 publications

(133 citation statements)

References 5 publications

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“…The number of viral particles and their survival time are key determining factors when consideration of reuse becomes necessary. 38,39 So far the evidence does not indicate a method that is consistently safe and effective to decontaminate N95 respiratory protection masks. Several of the published results are promising, in particular, hydrogen peroxide vapor, germicidal ultraviolet irradiation, dry heat ≤ 85 °C, moist heat/pasteurization, and microwaving.…”

Section: Discussionmentioning

confidence: 99%

Decontamination Methods for Respiratory Protection Mask Model N95: A Rapid Review

Probst

Guerrero

Cardoso

et al. 2020

Preprint

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Abstract Background: N95 respiratory protection masks are used by healthcare professionals to prevent contamination with infectious microorganisms transmitted by droplets or aerosols. Methods: We conducted a rapid review of the literature analyzing the effectiveness of decontamination methods for mask reuse. The review was carried out in April 2020 using a simplification of the formal systematic review process. A total of 166 articles were retrieved of which 17 laboratory-based studies were selected. Results: Two of the studies only examined the effectiveness of decontamination methods, seven only reported on the maintenance of mask integrity, and eight considered both outcomes. Twelve decontamination methods were included in the studies. Conclusions: Positive results should be considered with caution as they represent a small number of studies, reflect ideal laboratory conditions, and may have limited applicability in realistic situations and for health systems. Nonetheless, five methods appear promising: hydrogen peroxide vapor, ultraviolet irradiation, dry heat, wet heat/pasteurization, and microwave ovens.

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Section: Discussionmentioning

confidence: 99%

Decontamination Methods for Respiratory Protection Mask Model N95: A Rapid Review

Probst

Guerrero

Cardoso

et al. 2020

Preprint

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“…1 To meet this urgent need, healthcare institutions across the world have begun to utilize the germicidal properties of ultraviolet C (UVC) to decontaminate N95 respirators so that they can be reused. 2 It is clearly crucial that the dose of UVC delivered is sufficient to kill any viable SARS-CoV-2, the causative virus of the COVID-19 pandemic that may be present on the respirators.…”

Section: The Importance Of the Minimum Dosage Necessary For Uvc Deconmentioning

confidence: 99%

The importance of the minimum dosage necessary for UVC decontamination of N95 respirators during the COVID‐19 pandemic

Narla

Lyons

Kohli

et al. 2020

Photoderm Photoimm Photomed

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“…It is of brief significance to mention other technologies such as the use of UVC alongside HEPA filtration, as UVC has been used to disinfect equipment which may have come into contact with viruses such as SARS-CoV-2 [29] [30], however, little literature exists on how effective commercial air purification devices are at delivering a threshold dose.…”

Section: The Use Of Hepa Filters and Air Purificationmentioning

confidence: 99%

Using Computational Fluid Dynamics to Evaluate the Role of Air Purification in Reducing Fallow Time in Dentistry 

Raghava¹,

Vidovic²

2020

Preprint

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In dentistry, fallow time is a period which allows for airborne pathogens to settle out of the air and mitigate the risk of airborne infection transmission to dental professionals and staff. The current recommendation is a one hour period.Aims and Objectives We aim to show that air purification devices are an undervalued adjunctive measure to mitigate the risk of airborne transmission of pathogens, and so reduce fallow time.Methods Using a computational fluid dynamics software, we created a virtual dental surgery, and simulated a ten-minute aerosol generating procedure. We then modelled air flow in the room with no ventilation, and then the same room with an air purifier at a throughput of 430m3 h-1, and subsequently the room with one open window providing 6 ACH and no purifier. The particles released were monitored and their behaviour and airborne time measured and collated.Results and conclusions The room with no ventilation had a total particle number at 600s of 4.5million, which required 8400s to reduce by 99%. With an open window providing 6 ACH, we obtained a value of 2500s for a 99% reduction in airborne particles, and a similar peak particle volume. Conversely, when using an air purifier throughout the procedure, the peak particle number was ten times lower than the peak number without ventilation, or with an open window, and after the particle injection 99% airborne particle reduction was achieved 60s. Our findings suggest that the use of an air purifier greatly reduces the total particle volume in the air during the aerosol generating procedure, and the fallow period needed. The values found with 6 ACH and an open window are corroborated in other literature. The use of air purification could greatly reduce the risk of infection transmission in a dental surgery.

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Ultraviolet germicidal irradiation: Possible method for respirator disinfection to facilitate reuse during the COVID-19 pandemic

Cited by 146 publications

References 5 publications

Decontamination Methods for Respiratory Protection Mask Model N95: A Rapid Review

Decontamination Methods for Respiratory Protection Mask Model N95: A Rapid Review

The importance of the minimum dosage necessary for UVC decontamination of N95 respirators during the COVID‐19 pandemic

Using Computational Fluid Dynamics to Evaluate the Role of Air Purification in Reducing Fallow Time in Dentistry

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Ultraviolet germicidal irradiation: Possible method for respirator disinfection to facilitate reuse during the COVID-19 pandemic

Cited by 146 publications

References 5 publications

Decontamination Methods for Respiratory Protection Mask Model N95: A Rapid Review

Decontamination Methods for Respiratory Protection Mask Model N95: A Rapid Review

The importance of the minimum dosage necessary for UVC decontamination of N95 respirators during the COVID‐19 pandemic

Using Computational Fluid Dynamics to Evaluate the Role of Air Purification in Reducing Fallow Time in Dentistry&nbsp;

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Using Computational Fluid Dynamics to Evaluate the Role of Air Purification in Reducing Fallow Time in Dentistry