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.

COVID19 大流行的经验证明了分散在空气和表面环境中的生物制剂的真正关注。因此，需要一种快速、大规模的消毒方法来预防传染。COUNTERFOG® 是一项为大规模净化空气和表面而开发的创新技术。本研究的目的是通过实验评估 COUNTERFOG® 在消毒受病毒污染的表面方面的有效性。我们还旨在测量对所述表面进行消毒的必要时间。不锈钢表面被 φ29 噬菌体污染，并使用 COUNTERFOG® SDR-F05A+ 进行消毒，该产品使用不同浓度的次氯酸钠溶液和不同的暴露时间。在 1 分钟内获得超过 6 个对数病毒滴度的对数减少 1。直接应用时 2% 次氯酸钠；而在距应用点 5 厘米的径向距离处，消毒在 8 分钟内减少了 5.5 个对数。同样，次氯酸钠浓度（0.7% NaOCl）的更高稀释度需要更长的暴露时间（16 分钟）才能获得相同的对数减少（> 6 对数）。COUNTERFOG® 在很短的时间内在距离应用点 2 m 的地方形成一层薄薄的消毒剂，覆盖在表面上。浓度和暴露时间的选择对消毒效果至关重要。这些测试表明，0.7-1.2% 的次氯酸钠浓度足以快速有效地灭活 ɸ29 噬菌体。ɸ29 噬菌体比 SARS-CoV-2 更耐消毒这一事实支持了这种消毒程序。