scholarly journals Specificity of UV-C LED Disinfection Efficacy for Three N95 Respirators

Author(s):  
C. Carolina Ontiveros ◽  
David C. Shoults ◽  
Sean MacIsaac ◽  
Kyle D. Rauch ◽  
Crystal L. Sweeney ◽  
...  

Abstract The recent surge in the use of UV technology for personal protective equipment (PPE) has created a unique learning opportunity for the UV industry to deepen surface disinfection knowledge, especially on surfaces with complex geometries, such as the N95 filter facepiece respirators (FFR). The work outlined in this study addresses the interconnectedness of independent variables (e.g., UV Fluence, respirator material) that require consideration when assessing UV light efficacy for disinfecting respirators. Through electron microscopy and Fourier-transform infrared (FTIR) spectroscopy, we characterized respirator filter layers and revealed that polymer type affects disinfection efficacy. Specifically, FFR layers made from polypropylene (PP) (hydrophobic in nature) resulted in higher disinfection efficiency than layers composed of polyethylene terephthalate (PET-P) (hygroscopic in nature). An analysis of elastic band materials on the respirators indicated that silicone rubber-based bands achieved higher disinfection efficiency than PET-P bands and have a woven, fabric-like texture. While there is a strong desire to repurpose respirators, through this work we demonstrated that the design of an appropriate UV system is essential and that only respirators meeting specific design criteria may be reasonable for repurposing via UV disinfection.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Carolina Ontiveros ◽  
David C. Shoults ◽  
Sean MacIsaac ◽  
Kyle D. Rauch ◽  
Crystal L. Sweeney ◽  
...  

AbstractThe recent surge in the use of UV technology for personal protective equipment (PPE) has created a unique learning opportunity for the UV industry to deepen surface disinfection knowledge, especially on surfaces with complex geometries, such as the N95 filter facepiece respirators (FFR). The work outlined in this study addresses the interconnectedness of independent variables (e.g., UV Fluence, respirator material) that require consideration when assessing UV light efficacy for disinfecting respirators. Through electron microscopy and Fourier-transform infrared (FTIR) spectroscopy, we characterized respirator filter layers and revealed that polymer type affects disinfection efficacy. Specifically, FFR layers made from polypropylene (PP) (hydrophobic in nature) resulted in higher disinfection efficiency than layers composed of polyethylene terephthalate (PET-P) (hygroscopic in nature). An analysis of elastic band materials on the respirators indicated that silicone rubber-based bands achieved higher disinfection efficiency than PET-P bands and have a woven, fabric-like texture. While there is a strong desire to repurpose respirators, through this work we demonstrated that the design of an appropriate UV system is essential and that only respirators meeting specific design criteria may be reasonable for repurposing via UV disinfection.


Author(s):  
Er. S. K. Mude

Many of the ultraviolet (UV) sources used emit high intensities of UV light, capable of producing painful eye and skin burns. This paper provides information about the hazards associated with UV exposure and the safety precautions to take when working with these sources. Ultraviolet (UV) disinfection technology has existed for many years, but chemicals are still very prominent in disinfection applications today. UV disinfection does, however, provide many benefits over chemical options. It cannot be overdosed, and does not produce by-products, toxins, or volatile organic compound (VOC) emissions. It does not require the storage of hazardous materials and will not affect smell or taste in water and food disinfection applications. In addition, UV light is known to kill more waterborne microbes than chlorination. UV-C currency sanitizer is a fluid less device which can be used to perform the disinfection of various bacteria and viruses, it is based on UV-C light technology. It provides a portable ultraviolet disinfecting device for currency notes which comprises an acrylic case. The light is arranged in the top and bottom and inner layer coated with aluminum foil to increase the utilization of light rays.


Author(s):  
◽  
Kyle J. Card ◽  
Dena Crozier ◽  
Andrew Dhawan ◽  
Mina N. Dinh ◽  
...  

ABSTRACTDISCLAIMERThis article does not represent the official recommendation of the Cleveland Clinic or Case Western Reserve University School of Medicine, nor has it yet been peer reviewed. We are releasing it early, pre-peer review, to allow for quick dissemination/vetting by the scientific/clinical community given the necessity for rapid conservation of personal protective equipment (PPE) during this dire global situation. We welcome feedback from the community.Personal protective equipment (PPE), including face shields, surgical masks, and N95 respirators, is crucially important to the safety of both patients and medical personnel, particularly in the event of an infectious pandemic. As the incidence of Coronavirus Disease (COVID-19) increases exponentially in the United States and worldwide, healthcare provider demand for these necessities is currently outpacing supply. As such, strategies to extend the lifespan of the supply of medical equipment as safely as possible are critically important. In the midst of the current pandemic, there has been a concerted effort to identify viable ways to conserve PPE, including decontamination after use. Some hospitals have already begun using UV-C light to decontaminate N95 respirators and other PPE, but many lack the space or equipment to implement existing protocols. In this study, we outline a procedure by which PPE may be decontaminated using ultraviolet (UV) radiation in biosafety cabinets (BSCs), a common element of many academic, public health, and hospital laboratories, and discuss the dose ranges needed for effective decontamination of critical PPE. We further discuss obstacles to this approach including the possibility that the UV radiation levels vary within BSCs. Effective decontamination of N95 respirator masks or surgical masks requires UV-C doses of greater than 1 Jcm−2, which would take a minimum of 4.3 hours per side when placing the N95 at the bottom of the BSCs tested in this study. Elevating the N95 mask by 48 cm (so that it lies 19 cm from the top of the BSC) would enable the delivery of germicidal doses of UV-C in 62 minutes per side. Effective decontamination of face shields likely requires a much lower UV-C dose, and may be achieved by placing the face shields at the bottom of the BSC for 20 minutes per side. Our results are intended to provide support to healthcare organizations looking for alternative methods to extend their reserves of PPE. We recognize that institutions will require robust quality control processes to guarantee the efficacy of any implemented decontamination protocol. We also recognize that in certain situations such institutional resources may not be available; while we subscribe to the general principle that some degree of decontamination is preferable to re-use without decontamination, we would strongly advise that in such cases at least some degree of on-site verification of UV dose delivery be performed.


Author(s):  
Sarah E. Simmons ◽  
Ricardo Carrion ◽  
Kendra J. Alfson ◽  
Hilary M. Staples ◽  
Chetan Jinadatha ◽  
...  

Abstract Objectives: Prolonged survival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on environmental surfaces and personal protective equipment may lead to these surfaces transmitting this pathogen to others. We sought to determine the effectiveness of a pulsed-xenon ultraviolet (PX-UV) disinfection system in reducing the load of SARS-CoV-2 on hard surfaces and N95 respirators. Methods: Chamber slides and N95 respirator material were directly inoculated with SARS-CoV-2 and were exposed to different durations of PX-UV. Results: For hard surfaces, disinfection for 1, 2, and 5 minutes resulted in 3.53 log10, >4.54 log10, and >4.12 log10 reductions in viral load, respectively. For N95 respirators, disinfection for 5 minutes resulted in >4.79 log10 reduction in viral load. PX-UV significantly reduced SARS-CoV-2 on hard surfaces and N95 respirators. Conclusion: With the potential to rapidly disinfectant environmental surfaces and N95 respirators, PX-UV devices are a promising technology to reduce environmental and personal protective equipment bioburden and to enhance both healthcare worker and patient safety by reducing the risk of exposure to SARS-CoV-2.


Author(s):  
Sarah Simmons ◽  
Ricardo Carrion ◽  
Kendra Alfson ◽  
Hilary Staples ◽  
Chetan Jinadatha ◽  
...  

AbstractProlonged survival of SARS-CoV-2 on environmental surfaces and personal protective equipment (PPE) may lead to these surfaces transmitting disease to others. This article reports the effectiveness of a pulsed xenon ultraviolet (PX-UV) disinfection system in reducing the load of SARS-CoV-2 on hard surfaces and N95 respirators. Chamber slides and N95 respirator material were directly inoculated with SARS-CoV-2 and exposed to different durations of PX-UV disinfection. For hard surfaces, disinfection for 1, 2, and 5 minutes resulted in 3.53 Log10, >4.54 Log10, and >4.12 Log10 reductions in viral load, respectively. For N95 respirators, disinfection for 5 minutes resulted in >4.79 Log10 reduction in viral load. We found that PX-UV significantly reduces SARS-CoV-2 on hard surfaces and N95 respirators. With the potential to rapidly disinfectant environmental surfaces and N95 respirators, PX-UV devices are a promising technology for the reduction of environmental and PPE bioburden and to enhance both HCW and patient safety by reducing the risk of exposure to SARS-CoV-2.


2020 ◽  
Vol 35 (2) ◽  
pp. 139-146
Author(s):  
Abraham Amenay Zewde ◽  
Zifu Li ◽  
Lingling Zhang ◽  
Emanuel Alepu Odey ◽  
Zhou Xiaoqin

AbstractDue to world population growth, global climate change and the deteriorated quality of water, water supply struggles to keep up the clean water demand to meet human needs. Ultraviolet (UV) technology holds a great potential in advancing water and wastewater treatment to improve the efficiency of safe treatment. Over the last 20 years, the UV light disinfection industry has shown a tremendous growth. Therefore, reuse of wastewater contributes significantly to an efficient and sustainable water usage. Disinfection is a requirement for wastewater reuse due to the presence of a swarm of pathogens (e.g. bacteria, viruses, worms and protozoa) in secondary effluents. UV technology is widely favoured due to its environmentally friendly, chemical-free ability to provide high-log reductions of all known microorganisms, including chlorine-resistant strains such as Cryptosporidium. The UV disinfection process does not create disinfection by-products and unlike the chlorine UV disinfection process, it is not reliant on water temperature and pH. UV disinfection can eliminate the need to generate, handle, transport or store toxic/hazardous or corrosive chemicals and requires less space than other methods. As UV does not leave any residual effect that can be harmful to humans or aquatic life, it is safer for plant operators.


Author(s):  
Mariana de Cássia Artuni Rossi ◽  
Thaila Quatrini Corrêa ◽  
Kate Cristina Blanco ◽  
Vanderlei Salvador Bagnato ◽  
Ana Gabriela Salvio

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 801
Author(s):  
Talita Nicolau ◽  
Núbio Gomes Filho ◽  
Andrea Zille

In normal conditions, discarding single-use personal protective equipment after use is the rule for its users due to the possibility of being infected, particularly for masks and filtering facepiece respirators. When the demand for these protective tools is not satisfied by the companies supplying them, a scenario of shortages occurs, and new strategies must arise. One possible approach regards the disinfection of these pieces of equipment, but there are multiple methods. Analyzing these methods, Ultraviolet-C (UV-C) becomes an exciting option, given its germicidal capability. This paper aims to describe the state-of-the-art for UV-C sterilization in masks and filtering facepiece respirators. To achieve this goal, we adopted a systematic literature review in multiple databases added to a snowball method to make our sample as robust as possible and encompass a more significant number of studies. We found that UV-C’s germicidal capability is just as good as other sterilization methods. Combining this characteristic with other advantages makes UV-C sterilization desirable compared to other methods, despite its possible disadvantages.


2020 ◽  
pp. 153537022097781
Author(s):  
Douglas J Perkins ◽  
Robert A Nofchissey ◽  
Chunyan Ye ◽  
Nathan Donart ◽  
Alison Kell ◽  
...  

The ongoing pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a substantial strain on the supply of personal protective equipment, particularly the availability of N95 respirators for frontline healthcare personnel. These shortages have led to the creation of protocols to disinfect and reuse potentially contaminated personal protective equipment. A simple and inexpensive decontamination procedure that does not rely on the use of consumable supplies is dry heat incubation. Although reprocessing with this method has been shown to maintain the integrity of N95 respirators after multiple decontamination procedures, information on the ability of dry heat incubation to inactivate SARS-CoV-2 is largely unreported. Here, we show that dry heat incubation does not consistently inactivate SARS-CoV-2-contaminated N95 respirators, and that variation in experimental conditions can dramatically affect viability of the virus. Furthermore, we show that SARS-CoV-2 can survive on N95 respirators that remain at room temperature for at least five days. Collectively, our findings demonstrate that dry heat incubation procedures and ambient temperature for five days are not viable methods for inactivating SARS-CoV-2 on N95 respirators for potential reuse. We recommend that decontamination procedures being considered for the reuse of N95 respirators be validated at each individual site and that validation of the process must be thoroughly conducted using a defined protocol.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcelo Muñoz ◽  
Maxime Comtois-Bona ◽  
David Cortes ◽  
Cagla Eren Cimenci ◽  
Qiujiang Du ◽  
...  

AbstractThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for the COVID-19 global pandemic has infected over 25 million people worldwide and resulted in the death of millions. The COVID-19 pandemic has also resulted in a shortage of personal protective equipment (PPE) in many regions around the world, particularly in middle- and low-income countries. The shortages of PPE, such as N95 respirators, is something that will persist until an effective vaccine is made available. Thus, devices that while being easy to operate can also be rapidly deployed in health centers, and long-term residences without the need for major structural overhaul are instrumental to sustainably use N95 respirators. In this report, we present the design and validation of a decontamination device that combines UV-C & B irradiation with mild-temperature treatment. The device can decontaminate up to 20 masks in a cycle of < 30 min. The decontamination process did not damage or reduce the filtering capacity of the masks. Further, the efficacy of the device to eliminate microbes and viruses from the masks was also evaluated. The photothermal treatment of our device was capable of eradicating > 99.9999% of the bacteria and > 99.99% of the virus tested.


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