Mechanical Wiping Increases the Efficacy of Liquid Disinfectants on SARS-CoV-2

Abstract

High-touch environmental surfaces are acknowledged as potential sources of pathogen transmission, particularly in health care settings where infectious agents may be readily abundant. Methods of disinfecting these surfaces often include direct application of a chemical disinfectant or simply wiping the surface with a disinfectant pre-soaked wipe (DPW). In this study, we examine the ability of four disinfectants, ethanol (EtOH), sodium hypochlorite (NaOCl), chlorine dioxide (ClO2), and potassium monopersulfate (KMPS), to inactivate SARS-CoV-2 on a hard, non-porous surface, assessing the effects of concentration and contact time. The efficacy of DPWs to decontaminate carriers spiked with SARS-CoV-2, as well as the transferability of the virus from used DPWs to clean surfaces, is also assessed. Stainless steel carriers inoculated with approximately 6 logs of SARS-CoV-2 prepared in a soil load were disinfected within 5 min through exposure to 66.5% EtOH, 0.5% NaOCl, and 1% KMPS. The addition of mechanical wiping using DPWs impregnated with these biocides rendered the virus inactive almost immediately, with no viral transfer from the used DPW to adjacent surfaces. Carriers treated with 100 ppm of ClO2 showed a significant amount of viable virus remaining after 10 min of biocide exposure, while the virus was only completely inactivated after 10 min of treatment with 500 ppm of ClO2. Wiping SARS-CoV-2-spiked carriers with DPWs containing either concentration of ClO2 for 5 s left significant amounts of viable virus on the carriers. Furthermore, higher titers of infectious virus retained on the ClO2-infused DPWs were transferred to uninoculated carriers immediately after wiping. Overall, 66.5% EtOH, 0.5% NaOCl, and 1% KMPS appear to be highly effective biocidal agents against SARS-CoV-2, while ClO2 formulations are much less efficacious.

Efficacy of Peracetic Acid and Sodium Hypochlorite against SARS-CoV-2 on Contaminated Surfaces

“…Jung et al concluded that a 5-min contact time with 1,000 ppm NaOCl is effective against SARS-CoV-2; however, based on our results, it might be more prudent to use NaOCl on dirty surfaces at 1,000 ppm for 10 min. Sloan et al ( 33 ) followed an ASTM standard method and used both soil load with the virus and hard water for dilution of NaOCl; however, the authors only tested NaOCl at 5,000 ppm ( 33 ). Sloan et al ( 33 ) found that a 5,000 ppm and 1-min contact time do not consistently achieve > 3 log reduction, and that a 5-min contact time is required.…”

“…Sloan et al ( 33 ) followed an ASTM standard method and used both soil load with the virus and hard water for dilution of NaOCl; however, the authors only tested NaOCl at 5,000 ppm ( 33 ). Sloan et al ( 33 ) found that a 5,000 ppm and 1-min contact time do not consistently achieve > 3 log reduction, and that a 5-min contact time is required. Taken together, our results suggest that the WHO recommendation of 1-min contact time with 1,000 ppm NaOCl is not effective against SARS-CoV-2 on surfaces.…”

“…For example, in suspensions tests, 80 ppm for 10 s ( 30 ), 160 ppm for 30 min ( 31 ), 500 ppm for 5 min ( 32 ), and 1,400 ppm for 30 s ( 17 ) were reported to achieve > 3 log reduction in SARS-CoV-2 infectivity in the presence of a soil load. Furthermore, only two studies evaluated SARS-CoV-2 contaminated surfaces in the presence of soil load ( 18 , 33 ). Specifically, Jung et al ( 18 ) concluded that 1,000 ppm for 5 min was effective (> 3 log reduction), while Sloan et al ( 33 ) reported 5,000 ppm to be effective in 1 min.…”

“…Furthermore, only two studies evaluated SARS-CoV-2 contaminated surfaces in the presence of soil load ( 18 , 33 ). Specifically, Jung et al ( 18 ) concluded that 1,000 ppm for 5 min was effective (> 3 log reduction), while Sloan et al ( 33 ) reported 5,000 ppm to be effective in 1 min. However, NaOCl at high concentrations is corrosive to surfaces and harmful to human health because it irritates mucous membranes, skin, and airways ( 27 ).…”

Nematicidal Activity, Oxidative Stress and Phytotoxicity of Virkon®S on Tomato Plants Infected with Root-knot Nematode

“…Also, Virkon S is valid for nonporous hard surfaces, agricultural production equipment, vehicles, wheels, boot disinfection, and general farm sanitation. Virkon S, as a product, contains potassium monopersulphate (Oxone) and sodium dodecylbenzene sulfonate (SDBS), which have a broad spectrum of activity against viruses, some fungi and bacteria at 1% up to 3 % concentration (Carlisle, 2009;Sloan et al, 2022). Virkon S is also effective on nonporous hard surfaces, agricultural production equipment, vehicles, wheels, poultry, farm premises, disinfecting boots, and farms daily (Gabbert et al, 2020).…”