Robust Evaluation of Ultraviolet-C Sensitivity for SARS-CoV-2 and Surrogate Coronaviruses

Abstract

Disinfection of SARS-CoV-2 is of particular importance due to the global COVID-19 pandemic. UV-C irradiation is a compelling disinfection technique because it can be applied to surfaces, air, and water and is commonly used in drinking water and wastewater treatment facilities.

Rapid SARS-CoV-2 inactivation by mercury and LED UV-C lamps on different surfaces

“…Efficient inactivation of SARS-CoV-2 on contaminated surfaces (> 99.999% on plastic and steel and ≥ 99.8% on tissue, paper and cardboard) can be achieved by both the UV-C mercury lamp and the UV-C LED at a distance of 3 cm during 30 s. No infectious virus was detected after irradiation with the mercury UV-C lamp on a plastic surface for a UV-C dose of 7.14 mJ/cm 2 (10 cm, 5 s), which is in line with most previous studies [8,11,12]. Lower performances have been described for less powerful mercury lamps (4 W vs 18 W in this study) [4].…”

“…Lower performances have been described for less powerful mercury lamps (4 W vs 18 W in this study) [4]. This irradiation (7.14 mJ/cm 2 ) corresponded to a 6.4-log 10 decrease in SARS-CoV-2 TCID 50 /mL, rarely observed with other mercury lamps for comparable UV-C doses (3 to 4-log 10 decrease) [8,[11][12][13]. These other studies were probably limited more by a lower infectious titer of the viral inoculum than by the performances of the mercury lamps, because no infectious viruses were detected after irradiation [8,11,12].…”

“…This irradiation (7.14 mJ/cm 2 ) corresponded to a 6.4-log 10 decrease in SARS-CoV-2 TCID 50 /mL, rarely observed with other mercury lamps for comparable UV-C doses (3 to 4-log 10 decrease) [8,[11][12][13]. These other studies were probably limited more by a lower infectious titer of the viral inoculum than by the performances of the mercury lamps, because no infectious viruses were detected after irradiation [8,11,12]. A 4-log 10 reduction in SARS-CoV-2 TCID 50 was observed after irradiation with the UV-C LED light at 3.2 mJ/cm 2 (10 cm, 5 s) on plastic.…”

Inactivation of aerosolized SARS‐CoV ‐2 by 254 nm UV‐C irradiation

“…Regarding decontamination of coronaviruses, it was previously shown that non‐human coronaviruses as well as common‐cold coronaviruses and SARS‐CoV are sensitive to inactivation by UV‐C irradiation 10,12–16 . Accordingly, as expected, our group and others have demonstrated that SARS‐CoV‐2 can also be UV‐inactivated from liquids and dried surfaces 17–27 . Although some studies published high UV‐C doses of 100–300 mJ/cm 2 to be required for reaching 1‐log reduction on viral titers, 16,22 the vast majority of studies performed at 254 nm irradiation, reported doses ranging from 1.2 to 7 mJ/cm 2 to achieve the same reduction.…”

Rapid SARS-CoV-2 disinfection on distant surfaces with UV-C: The inactivation is affected by the type of material

“…The most common disinfection measures in public places include the use of chemical agents and exposure to short wavelength ultraviolet radiation (UV-C), which has shown to be very efficient to inactivate SARS-CoV-2 in several laboratory studies [6] , [7] , [8] , [9] , [10] , [11] , [12] . Recently, technological solutions combining mobile robotics and UV-C are being developed [13] , which could allow virus inactivation without human intervention.…”