A coronavirus (SARS-CoV-2) has caused a global pandemic and associated morbidity and mortality resultant from COVID-19. As a result of efforts to control direct (person to person) and indirect (contaminated objects, s...A coronavirus (SARS-CoV-2) has caused a global pandemic and associated morbidity and mortality resultant from COVID-19. As a result of efforts to control direct (person to person) and indirect (contaminated objects, surfaces, indoor air) transmission of the virus, various interventions have been evaluated. Studies were conducted to evaluate the efficacy of commercially available chlorine dioxide (CD) products to reduce viral loads on PPE (face masks) and surfaces using a novel dry gas release intervention. The efficacy of CD slow release 30-day sachets was tested on N95 face masks inoculated with human coronavirus OC43 in suspension. One sachet was placed with an inoculated mask in plastic resealable bags. Three trials were completed using the original sachet where a mask and sachet were placed into a plastic bag for 13 hours per sachet age of 1 day, 14 days, and 30 days. The amount of CD generated during a 13-hour treatment period was 0.30 mg. The nominal concentration of CD was estimated to be 317 mg/m<sup>3</sup>. All three tests demonstrated at least a 99.91% reduction of viral loading in the mask versus a non-treated control. Efficacy of CD dry gas fast releasing pods (Ultrashok) for fumigation was also tested in a 1344 ft<sup>3</sup> closed room. Two pods were placed in the space and CD surface virucidal efficacy was tested in three locations of the room after 1 hour and 2 hours of dwell time. The estimated nominal peak concentration was 15 ppmv in the room. The one-hour exposure saw a >99.91% OC43 reduction on surfaces and the two-hour exposure resulted in a >99.997% OC43 reduction on surfaces versus a non-treated control. These results indicate dry CD is highly effective against human coronavirus. CD was 99.91% effective for eliminating human coronavirus OC43 in both sachet and capsule fumigant form using both fast and slow release mechanisms. Rapid fumigant application is suitable for contaminated rooms, ambulances, emergency vehicles, and many types of PPE, most particularly porous PPE materials. The gaseous state of CD allows for rapid diffusion and transfer of the virucidal stable free radical to all surfaces of PPE and indoor areas that would favor virus survival. Additionally, this work suggests CD can be effective at levels with significant margins of safety (little to no exposure and rapid degradation of residuals) providing minimal public health risks associated with the use of CD.展开更多
The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown thi...The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown this intervention to be an effective mitigation strategy against viral, bacterial, and fungal elements in ambient air. There is an array of available products for generating ClO<sub>2</sub> gas however most involve the use of expensive or sophisticated technology that makes their applicability limited to specialized consumers. The purpose of this study was to determine the virucidal efficacy of three pragmatic and affordable, ClO<sub>2</sub> generating products using an aerosolized MS2 surrogate in a sealed chamber room under five different scenarios. The products tested included: Ultrashock—a ClO<sub>2</sub> releasing pod (30 ppmv), Filter Media—a ClO<sub>2</sub> impregnated zeolite media made to fit into an air blower housing (<0.01 ppmv) and Flow Stick—a smaller ClO<sub>2</sub> impregnated media filled air reactor tube (<0.01 ppmv). Testing scenarios included product deployment post MS2 bioaerosol introduction (Ultrashock and Filter Media), during MS2 bioaerosol introduction (Filter Media and Flow Stick) and prior to MS2 bioaerosol introduction (Filter Media). MS2 surface samples were collected using sterile petri-dishes and MS2 and ClO<sub>2</sub> air samples were collected from sampling ports on the outer chamber wall at 0, 90 and 180 minutes. The Ultrashock and Filter Media with air flow in the rapid sweep scenario showed the greatest reduction in air MS2 (T<sub>180</sub> = 99.992% and T<sub>180</sub> = 99.996% respectively) compared to the control (T<sub>180 </sub>= 99.6%). When compared to the control results, the filter media with air flow engaged prior to the introduction of MS2 yielded reductions of 99.87% and 99.93% in air and on surfaces respectively at T<sub>0</sub>, demonstrating the protective effect residual ClO2 has against air and surface contamination. These product formats have potential uses as remedial and preventative interventions against viral constituents in air and should undergo further evaluation to determine efficacy and human health risk.展开更多
文摘A coronavirus (SARS-CoV-2) has caused a global pandemic and associated morbidity and mortality resultant from COVID-19. As a result of efforts to control direct (person to person) and indirect (contaminated objects, surfaces, indoor air) transmission of the virus, various interventions have been evaluated. Studies were conducted to evaluate the efficacy of commercially available chlorine dioxide (CD) products to reduce viral loads on PPE (face masks) and surfaces using a novel dry gas release intervention. The efficacy of CD slow release 30-day sachets was tested on N95 face masks inoculated with human coronavirus OC43 in suspension. One sachet was placed with an inoculated mask in plastic resealable bags. Three trials were completed using the original sachet where a mask and sachet were placed into a plastic bag for 13 hours per sachet age of 1 day, 14 days, and 30 days. The amount of CD generated during a 13-hour treatment period was 0.30 mg. The nominal concentration of CD was estimated to be 317 mg/m<sup>3</sup>. All three tests demonstrated at least a 99.91% reduction of viral loading in the mask versus a non-treated control. Efficacy of CD dry gas fast releasing pods (Ultrashok) for fumigation was also tested in a 1344 ft<sup>3</sup> closed room. Two pods were placed in the space and CD surface virucidal efficacy was tested in three locations of the room after 1 hour and 2 hours of dwell time. The estimated nominal peak concentration was 15 ppmv in the room. The one-hour exposure saw a >99.91% OC43 reduction on surfaces and the two-hour exposure resulted in a >99.997% OC43 reduction on surfaces versus a non-treated control. These results indicate dry CD is highly effective against human coronavirus. CD was 99.91% effective for eliminating human coronavirus OC43 in both sachet and capsule fumigant form using both fast and slow release mechanisms. Rapid fumigant application is suitable for contaminated rooms, ambulances, emergency vehicles, and many types of PPE, most particularly porous PPE materials. The gaseous state of CD allows for rapid diffusion and transfer of the virucidal stable free radical to all surfaces of PPE and indoor areas that would favor virus survival. Additionally, this work suggests CD can be effective at levels with significant margins of safety (little to no exposure and rapid degradation of residuals) providing minimal public health risks associated with the use of CD.
文摘The ongoing SARS-CoV-2 outbreak has rapidly increased the desire to manage bioaerosol exposures in indoor settings. Studies using chlorine dioxide gas (ClO<sub>2</sub>) at low concentrations have shown this intervention to be an effective mitigation strategy against viral, bacterial, and fungal elements in ambient air. There is an array of available products for generating ClO<sub>2</sub> gas however most involve the use of expensive or sophisticated technology that makes their applicability limited to specialized consumers. The purpose of this study was to determine the virucidal efficacy of three pragmatic and affordable, ClO<sub>2</sub> generating products using an aerosolized MS2 surrogate in a sealed chamber room under five different scenarios. The products tested included: Ultrashock—a ClO<sub>2</sub> releasing pod (30 ppmv), Filter Media—a ClO<sub>2</sub> impregnated zeolite media made to fit into an air blower housing (<0.01 ppmv) and Flow Stick—a smaller ClO<sub>2</sub> impregnated media filled air reactor tube (<0.01 ppmv). Testing scenarios included product deployment post MS2 bioaerosol introduction (Ultrashock and Filter Media), during MS2 bioaerosol introduction (Filter Media and Flow Stick) and prior to MS2 bioaerosol introduction (Filter Media). MS2 surface samples were collected using sterile petri-dishes and MS2 and ClO<sub>2</sub> air samples were collected from sampling ports on the outer chamber wall at 0, 90 and 180 minutes. The Ultrashock and Filter Media with air flow in the rapid sweep scenario showed the greatest reduction in air MS2 (T<sub>180</sub> = 99.992% and T<sub>180</sub> = 99.996% respectively) compared to the control (T<sub>180 </sub>= 99.6%). When compared to the control results, the filter media with air flow engaged prior to the introduction of MS2 yielded reductions of 99.87% and 99.93% in air and on surfaces respectively at T<sub>0</sub>, demonstrating the protective effect residual ClO2 has against air and surface contamination. These product formats have potential uses as remedial and preventative interventions against viral constituents in air and should undergo further evaluation to determine efficacy and human health risk.
