Assessment of Surface Disinfection Effectiveness of Decontamination System COUNTERFOG® SDR-F05A+ Against Bacteriophage ɸ29

• Published in: Food and environmental virology 2022, Vol.14 (3), p.304-313
• Main Authors: del Álamo, Cristina, Vázquez-Calvo, Ángela, Alcamí, Antonio, Sánchez-García-Casarrubios, Juan, Pérez-Díaz, José Luis
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Biomedicine; Chemistry/Food Science; COVID-19; Decontamination; Dilution; Disinfectants; Disinfection; Disinfection & disinfectants; Effectiveness; Exposure; Food Science; Inactivation; Original Paper; Pandemics; Phages; Reduction; Severe acute respiratory syndrome coronavirus 2; Sodium; Sodium hypochlorite; Stainless steel; Stainless steels; Viral diseases; Virology; Viruses
• ISSN: 1867-0334; 1867-0342
• DOI: 10.1007/s12560-022-09526-z

The experience of COVID19 pandemic has demonstrated the real concern of biological agents dispersed in the air and surfaces environments. Therefore, the need of a fast and large-scale disinfection method has arisen for prevention of contagion. COUNTERFOG® is an innovative technology developed for large-scale decontamination of air and surfaces. The objective of this study is to assess experimentally the effectiveness of COUNTERFOG® in disinfecting viral-contaminated surfaces. We also aim to measure the necessary time to disinfect said surfaces. Stainless steel surfaces were contaminated with bacteriophage φ29 and disinfected using COUNTERFOG® SDR-F05A+, which uses a sodium hypochlorite solution at different concentrations and for different exposure times. A log reduction over 6 logs of virus titer is obtained in 1 min with 1.2% sodium hypochlorite when the application is direct; while at a radial distance of 5 cm from the point of application the disinfection reaches a reduction of 5.5 logs in 8 min. In the same way, a higher dilution of the sodium hypochlorite concentration (0.7% NaOCl) requires more exposure time (16 min) to obtain the same log reduction (> 6 logs). COUNTERFOG® creates, in a short time and at a distance of 2 m from the point of application, a thin layer of disinfectant that covers the surfaces. The selection of the concentration and exposure time is critical for the efficacy of disinfection. These tests demonstrate that a concentration between 0.7- 1.2% sodium hypochlorite is enough for a fast and efficient ɸ29 phage inactivation. The fact that ɸ29 phage is more resistant to disinfection than SARS-CoV-2 sustains this disinfection procedure.