Bactericidal Efficacy of So-Called Sanitizers in Japan

Commercially available so-called sanitizers in Japan are often touted as having remarkable "sanitizing (jokin)" effect, "virus-removal" capabilities, and "99.99%" removal rate of microbes and pathogens. In this study, we investigated the bactericidal efficacy of these so-called sanitizers for environmental surfaces against Enterococcus faecalis and Pseudomonas aeruginosa. Of note, out of 43 products, 24 (55.8%) did not exhibit bactericidal effects on either Enterococcus or Pseudomonas. Among these 43 products, there were no bactericidal effects in 9 (47.4%) of 19 products that stated as containing "alcohol" as the formula; as well as 4 (80%) of 5 products stating only "benzalkonium chloride"; similarly no effect in 5 (83.3%) of 6 stating only"chlorine chemicals." Furthermore, 6 (46.2%) of 13 products that stated components other than alcohol, benzalkonium chloride, and chlorine chemicals on the product container or with no description of constituent components failed to show any bactericidal effects. Four disinfectants (alcohol for disinfection, 0.1% benzalkonium chloride, 0.05% (500 ppm) hypochlorite, 0.1% (1000 ppm) hypochlorite) as control showed bactericidal effect. The lack of bactericidal activity in nearly half of sanitizers may be explained by the low concentration of the effective ingredient such as alcohol, benzalkonium chloride, and hypochlorite. In sanitizers containing hypochlorite, degradation of hypochlorite with prolongation of time after manufacturing may be another reason.