Abstract
After being permitted as a food additive in 2002, slightly acidic electrolyzed water (SAEW) was expected to be a low-irritant disinfectant. However, its safety when applied on human skin has not yet been confirmed. This study aimed to identify the toxicity of SAEW for human skin. This double-blind, placebo-controlled trial included 20 subjects ranging
in age from 20 to 50 years who had normal skin on their forearms at the time of study entry. Two spray bottles, A and B, containing SAEW or distilled water (DW), were distributed to all subjects. The reagents were randomly assigned so that neither the subjects nor the researchers knew which container, A or B, contained the SAEW or DW. The subjects applied a single spray (approx. 2 mL) of A and B to their left and right forearms, respectively, once daily for one week as the intervention period. The subjects were instructed not to touch or rub the sprayed areas of their forearms until the reagent had dried. To assess the resultant skin condition, stratum corneum hydration, sebum secretion, transepidermal water loss, skin pH, resident flora, and multiple biomarker assay of tape-stripped stratum corneum from the site of the forearm where the spray was applied were evaluated before and after the intervention period. The results showed that there were no differences between the skin sprayed with SAEW and DW both before and after the intervention period. In addition, SAEW did not induce any skin irritation. Our findings suggested that SAEW can be safely applied on human skin.
