Can hypochlorous acid be a powerful sanitizer to replace alcohol for disinfection ? —Its bactericidal, degradation of the solutions under various storage condition, and steel rust effects

Abstract

Coronavirus disease pandemic has led to a shortage of disinfectant alcohol (DA; 76.9-81.4% ethanol solution) in Japan. This study investigated the availability of hypochlorous acid (HA) as an alternative disinfectant to DA in clinical environment. HA is a safe and economical disinfectant with a broad antibacterial spectrum and low risk of hand irritation, which is used worldwide. In this study, HA and sodium hypochlorite solution (SH) were degraded over time and the degradation was accelerated by temperature and lighting. Results of bactericidal effects of HA revealed that the realistic effective concentration should be 200 ppm. Compared with DA, the dental carbon steel burs were more severely rusted by SH and HA. These results indicated that high concentration of HA generated on-site could be an effective and safe disinfectant for use immediately after generation with consideration of object materials in clinical environment, as an alternative to DA.

Electrolysed oxidising water as a multi‐purpose biocide in dental healthcare—A scoping review

“…Storage‐related changes to POU EOW properties were reported in only four studies 57–60 ; one study evaluated RTU preparations 61 and one study compared various POU and RTU preparations 62 (Table S2). Properties of POU EOW 57–60 were measured over periods ranging from 21 to 120 days under various storage conditions (open/closed/dark, 57 room temperature/refrigerated, 58,60 capped/uncapped bottles, transparent/opaque bottles, 58,60 exposed/shaded to/from sunlight and the presence/absence of headspace within bottles 59 ).…”

“…The single storage‐related report on RTU neutral‐pH EOW, measured pH and antimicrobial activity following 1 week of storage in the light 61 . One study compared the storage‐related degradation of POU preparations generated by two different methods and five different commercial RTU solutions that were evaluated for up to 30 days for samples that were stored under room temperature or refrigerated and exposed to light or kept under shaded conditions 62 …”

“…Measurements included liquid (suspension) assays, agar diffusion assays and anti‐biofilm assays. Liquid growth/viability assays were performed either as stand‐alone procedures or prior to anti‐biofilm activity measurements (30 reports 9,50,57,58,60–85 ) and as a comparative method in one 86 of the four reports that investigated EOW effectiveness by agar diffusion assays 66,86–88 . In vitro adherence and anti‐biofilm assays (36 reports) were performed using laboratory biofilm models (11 reports, 70,73–75,77–79,89–92 ), extracted human teeth (14 reports 90,91,93–104 ), bovine teeth (1 report 105 ) and biomaterial substrates (10 reports 24,61,83,106–112 ).…”

“…In vitro evaluations focused on cross‐infection control in dental settings (dental operatory, instruments or DUWLs) have been undertaken with various EOW preparations in five studies 62,63,68,85,89 . EOW (POU and RTU) efficacy has been evaluated against Herpes Simplex Virus type 1 (HSV‐1), polio virus and oral pathogenic bacteria by suspension viability assays in three reports 62,63,68 .…”

“…In vitro evaluations focused on cross‐infection control in dental settings (dental operatory, instruments or DUWLs) have been undertaken with various EOW preparations in five studies 62,63,68,85,89 . EOW (POU and RTU) efficacy has been evaluated against Herpes Simplex Virus type 1 (HSV‐1), polio virus and oral pathogenic bacteria by suspension viability assays in three reports 62,63,68 . Reduction in total viable counts and biofilm cover in an in vitro model of DUWLs was evaluated in one study that compared 23 commercial chemical disinfectants including a moderately‐acidic EOW 89 .…”