scholarly journals Effect of Ultraviolet C Disinfection Treatment on the Nanomechanical and Topographic Properties of N95 Respirator Filtration Microfibers

MRS Advances ◽  
2020 ◽  
Vol 5 (56) ◽  
pp. 2863-2872
Author(s):  
Yujie Meng ◽  
Rae Zeng ◽  
Kurt Rubin ◽  
Kelly Barry
Keyword(s):  
Young’S Modulus ◽  
Breaking Strength ◽  
Ultraviolet Germicidal Irradiation ◽  
Measurement Results ◽  
Ultraviolet C ◽  
N95 Respirators ◽  
Uvc Radiation ◽  
Different Doses ◽  
Accumulated Dose ◽  
Fiber Breaking

AbstractUltraviolet germicidal irradiation (UVGI) N95 filtering facepiece respirator (FFR) treatment is considered an effective decontamination approach to address the supply shortage of N95 FFRs during the ongoing Covid-19 pandemic. In this study, we investigated the nanomechanical and topographic properties of filtration fibers that have been exposed to different doses of UVC radiation. UVC exposure was shown to decrease both Young's modulus (E), hardness (H) and fiber width, as measured on individual polypropylene (PP) fibers. Our results also show that the PP microfiber layer loses its strength when N95 respirators are exposed to an accumulated UVC dose during the process of decontamination, and the PP fiber width also exhibits a logarithmic decrease during UVC exposure. The nanoscale measurement results on individual fibers suggest that maximum cycles of UVC disinfection treatment should be limited due to excessive accumulated dose, which has the potential to decrease the fiber breaking strength.

scholarly journals The Effect of Ultraviolet C Radiation Against SARS-CoV-2 Inoculated N95 Respirators

2020 ◽  
Author(s):  
David M. Ozog ◽  
Jonathan Z. Sexton ◽  
Shanthi Narla ◽  
Carla D. Pretto-Kernahan ◽  
Carmen Mirabelli ◽  
...  
Keyword(s):  
Healthcare Personnel ◽  
Dependent Manner ◽  
Infectious Dose ◽  
Frontline Workers ◽  
Viral Stock ◽  
Fit Testing ◽  
Ultraviolet C ◽  
N95 Respirators ◽  
Dose Dependent ◽  
Uvc Radiation

AbstractSince March 31st, 2020, during the height of the pandemic, we have decontaminated thousands of 3M 1860 respirators with Ultraviolet C (UVC) for our frontline workers. There is no published peer-reviewed data regarding the dose required to effectively disinfect SARS-CoV-2 on N95 filtering facepiece respirators (FFRs). Four different locations (facepiece and strap) on 5 different N95 FFR models (3M 1860, 8210, 8511, 9211; Moldex 1511) were inoculated with a 10 μL drop of SARS-CoV-2 viral stock (8 × 107 TCID50/mL). The outside-facing and wearer-facing surfaces of the respirators were each irradiated with a dose of 1.5 J/cm2 UVC (254 nm).Viable SARS-CoV-2 was quantified by a median tissue culture infectious dose assay (TCID50). UVC delivered using a dose of 1.5 J/cm2, to each side, was an effective method of decontamination for the facepieces of 3M 1860 and Moldex 1511, and for the straps of 3M 8210 and the Moldex 1511. This dose is an appropriate decontamination method to facilitate reuse of respirators for healthcare personnel when applied to certain models/materials. Increasing the dose may improve decontamination for the other models and straps; however, UVC radiation can degrade certain polymers in a dose dependent manner, and the effects may vary greatly between different models. Therefore, fit-testing of UVC decontaminated respirators must be performed each time a new model and/or dose is introduced into the healthcare system.

scholarly journals Mapping of UV-C dose and SARS-CoV-2 viral inactivation across N95 respirators during decontamination

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alisha Geldert ◽  
Alison Su ◽  
Allison W. Roberts ◽  
Guillaume Golovkine ◽  
Samantha M. Grist ◽  
...  
Keyword(s):  
Optical Simulation ◽  
Pathogen Inactivation ◽  
Viral Inactivation ◽  
Flexible Form ◽  
Measurement Tools ◽  
Ultraviolet C ◽  
N95 Respirators ◽  
Uv C ◽  
Dose Difference

AbstractDuring public health crises like the COVID-19 pandemic, ultraviolet-C (UV-C) decontamination of N95 respirators for emergency reuse has been implemented to mitigate shortages. Pathogen photoinactivation efficacy depends critically on UV-C dose, which is distance- and angle-dependent and thus varies substantially across N95 surfaces within a decontamination system. Due to nonuniform and system-dependent UV-C dose distributions, characterizing UV-C dose and resulting pathogen inactivation with sufficient spatial resolution on-N95 is key to designing and validating UV-C decontamination protocols. However, robust quantification of UV-C dose across N95 facepieces presents challenges, as few UV-C measurement tools have sufficient (1) small, flexible form factor, and (2) angular response. To address this gap, we combine optical modeling and quantitative photochromic indicator (PCI) dosimetry with viral inactivation assays to generate high-resolution maps of “on-N95” UV-C dose and concomitant SARS-CoV-2 viral inactivation across N95 facepieces within a commercial decontamination chamber. Using modeling to rapidly identify on-N95 locations of interest, in-situ measurements report a 17.4 ± 5.0-fold dose difference across N95 facepieces in the chamber, yielding 2.9 ± 0.2-log variation in SARS-CoV-2 inactivation. UV-C dose at several on-N95 locations was lower than the lowest-dose locations on the chamber floor, highlighting the importance of on-N95 dose validation. Overall, we integrate optical simulation with in-situ PCI dosimetry to relate UV-C dose and viral inactivation at specific on-N95 locations, establishing a versatile approach to characterize UV-C photoinactivation of pathogens contaminating complex substrates such as N95s.

scholarly journals The effect of ultraviolet C radiation against different N95 respirators inoculated with SARS-CoV-2

2020 ◽  
Vol 100 ◽  
pp. 224-229 ◽  
Author(s):  
David M. Ozog ◽  
Jonathan Z. Sexton ◽  
Shanthi Narla ◽  
Carla D. Pretto-Kernahan ◽  
Carmen Mirabelli ◽  
...  
Keyword(s):  
Ultraviolet C ◽  
N95 Respirators

scholarly journals Ultraviolet-C and other methods of decontamination of filtering facepiece N-95 respirators during the COVID-19 pandemic

2020 ◽  
Vol 19 (6) ◽  
pp. 746-751 ◽  
Author(s):  
Angeli Eloise Torres ◽  
Alexis B. Lyons ◽  
Shanthi Narla ◽  
Indermeet Kohli ◽  
Angela Parks-Miller ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ultraviolet Germicidal Irradiation ◽  
Ultraviolet C ◽  
Dry Heating

Ultraviolet germicidal irradiation is one method for decontamination of N-95 filtering facepiece respirators to facilitate reuse during the COVID-19 pandemic. Other techniques include hydrogen peroxide vaporization, microwave-generated steaming, and dry heating.

scholarly journals Homegrown Ultraviolet Germicidal Irradiation for Hospital-Based N95 Decontamination during the COVID-19 Pandemic

2020 ◽  
Author(s):  
Eric Schnell ◽  
Melanie J. Harriff ◽  
Jane E. Yates ◽  
Elham Karamooz ◽  
Christopher D. Pfeiffer ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Healthcare Workers ◽  
Global Supply Chains ◽  
Protective Equipment ◽  
Respiratory Protection ◽  
Exposure Risk ◽  
High Demand ◽  
Ultraviolet Germicidal Irradiation ◽  
Global Pandemic ◽  
Ultraviolet C

AbstractCoronavirus disease (COVID-19), the disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is responsible for the 2020 global pandemic and characterized by high transmissibility and morbidity. Healthcare workers (HCWs) are at risk of contracting COVID-19, and this risk is mitigated through the use of personal protective equipment such as N95 Filtering Facepiece Respirators (FFRs). The high demand for FFRs is not currently met by global supply chains, potentially placing HCWs at increased exposure risk. Effective FFR decontamination modalities exist, which could maintain respiratory protection for HCWs in the midst of the current pandemic, through the decontamination and re-use of FFRs. Here, we present a locally-implemented ultraviolet-C germicidal irradiation (UVGI)-based FFR decontamination pathway, utilizing a home-built UVGI array assembled entirely with previously existing components available at our institution. We provide recommendations on the construction of similar systems, as well as guidance and strategies towards successful institutional implementation of FFR decontamination.

scholarly journals Standalone Solar-Powered Ultraviolet Mobile Disinfectant: Bringing Solar Energy in the Global Fight against COVID-19

2020 ◽  
Author(s):  
Nassim Ahmed Mahammedi ◽  
Adel Mahammedi
Keyword(s):  
Open Source ◽  
Portable Devices ◽  
Pv System ◽  
Ultraviolet Germicidal Irradiation ◽  
Wide Range ◽  
Ultraviolet C ◽  
Solar Powered ◽  
Bacteria And Fungi ◽  
A Charge ◽  
Disinfection Unit

As the first initiative of its kind in Algeria, here is presented a solar-powered mobile “Ultraviolet Germicidal Irradiation” disinfection unit (UVGI) based on a special germicidal ultraviolet-C (UVC) radiator. The system was designed to disinfect several objects such as: medical tools, reusable masks, face-shields, gloves, phones, laptops, keys, money and many other portable devices that need to be disinfected/sterilized. It offers the advantage of complete autonomy through the built-in photovoltaic (PV) system that includes a solar panel, a gel battery, a charge controller and a power inverter. The system provides an extra 220V-50Hz outlet with 375VA maximum power to be used when energy is needed. The system is easily scalable to generate higher ultraviolet dosages by adding more UVC lamps. The chemical-free germicidal UVC sanitizing method employed by this device effectively disactivates a very wide range of microorganisms (microbes, bacteria and fungi and viruses including the actual SARS-CoV-2 that causes COVID-19 respiratory disease) and it has several advantages in comparison to chemical-based sanitizing methods. The total cost to make this open source device is below 1000 € and is easily customizable and scalable. This device is an open source, secure and fast equipment for objects and surface disinfection. The device will be fully automated by adding PIR sensors or remote control after further funding will be received.

scholarly journals The Effectiveness of Commercial Household Ultraviolet C Germicidal Devices in Thailand

2021 ◽  
Author(s):  
Pasita Palakornkitti ◽  
Prinpat Pinyowiwat ◽  
Somsak Tanrattanakorn ◽  
Natta Rajatanavin ◽  
Ploysyne Rattanakaemakorn
Keyword(s):  
Experimental Study ◽  
Side Effects ◽  
Severe Acute Respiratory Syndrome ◽  
Personal Hygiene ◽  
Cycle Duration ◽  
Global Awareness ◽  
Surface Disinfection ◽  
Ultraviolet Germicidal Irradiation ◽  
Commercial Market ◽  
Ultraviolet C

Abstract Ultraviolet C (UVC), also called ultraviolet germicidal irradiation (UVGI), is known for its effective air, water, and surface disinfectant properties. With the rise of global awareness about public sanitation and personal hygiene due to the emergence of the current coronavirus disease 2019 pandemic, several applications of UVC were developed and introduced to the commercial market. The present experimental study was conducted to evaluate the effectiveness of commercial household ultraviolet C germicidal devices for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivation. UVC dosages (mJ/cm2) of 10 UVC devices were determined at the recommended settings and compared to a UVC dosage benchmark for SARS-CoV-2 inactivated UVC dosage (3.7 mJ/cm2). Of the 10 devices, 3 were handheld UVGI surface disinfection equipment, 4 were UVGI disinfection chambers, and 3 were movable UVGI air and surface purifiers. Three UVGI disinfection chambers and all movable UVGI air and surface purifiers provided sufficient UVC dosages for SARS-CoV-2 inactivation. None of the studied handheld UVGI surface disinfection equipment achieved the UVC dosage for SARS-CoV-2 inactivation. A lack of standardization in the distance and cycle duration for each UVC application was observed. Standard usage guidelines for UVC devices are required to improve the effectiveness of UVC irradiance for SARS-CoV-2 inactivation as well as to minimize the potential side effects of UVC.

scholarly journals Cost-Effective Disinfection Robot Using UVC Radiation

2021 ◽  
Vol 40 ◽  
pp. 02003
Author(s):  
Mansi Dhikle ◽  
Vinaya Dharne ◽  
Pankaja Gaikar ◽  
Kausar Fakir
Keyword(s):  
Video Streaming ◽  
Uv Light ◽  
Low Cost ◽  
Cost Effective ◽  
Live Video ◽  
Medical Facilities ◽  
Ultraviolet C ◽  
Cleaning Robots ◽  
Uv C ◽  
Uvc Radiation

Sanitization with human efforts is not an easy task. Chances of contracting infections increases which leads to additional spread of bacteria. Currently, normal cleaning robots are used in most of the places but looking at the current situation the sanitization techniques need to be improved. The robot uses radiation of UV rays to kill the microrganisms. It gives a live video streaming of its surrounding using a Wi-fi based camera. With the help of Bluetooth module and android mobile, we can control the movement of the robot inside the room without being physically present. It is built with PIC Microcontroller and Ultraviolet-C (UVC) Sanitization LED. UV-C has bandwidth range of 200-280nm and is most powerful when it comes to killing pathogens in the room. This allows us to sterilise the room effectively. By killing the germs, the UV light restricts their multiplication by destroying their reproductive system. Thus use of this robot lowers the threat of infection, cost of traditional cleaning and sterilisation and increases security in medical facilities. Thus, we are trying to implement a more efficient way of sanitization by building a Low cost UV sanitization Robot which can be used in small clinics and for household purpose.

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