Testing the antibacterial efficacy of various commercially available alcohol-based hand antiseptics and the world health organization formulation II with the EN 1500 standard

Abstract

Objective: The European Norm (EN) 1500 standard, which was developed to evaluate the antibacterial efficacy of widely used hand rub agents, is the most common in vivo test method used in Europe and has been accepted by the Turkish Standards Institute. This study aimed to test five antiseptic products supplied from the market and the hand antiseptic formulation II recommended by the World Health Organization (WHO-II) for two application types using the EN 1500.Methods: In the first application, the hands were rubbed with 3 mL of antiseptic for 30 seconds (1x3 ml; 30 sec); in the second application, which lasted 60 seconds, the hands were rubbed with 3 ml of antiseptic for 30 seconds, and the same process was repeated once more (2x3 ml; 2x30 sec). After the participants' hands were artificially contaminated with Escherichia coli K12 standard strain, the bactericidal efficacy of the tested antiseptics was compared with the ap-plication of a 60% by volume isopropyl alcohol solution (2x3 ml; 2x30 sec) as the reference procedure.Results: When the antiseptics were tested, and WHO-II was applied in the form of "1x3 ml; 30 sec", they were found to be significantly less effective than the reference procedure and did not meet the EN 1500. On the other hand, when they were applied in the "2x3 ml; 2x30 sec" procedure, all of them met the EN 1500.Conclusion: Tested antiseptic products and WHO-II should be applied in the form of "2x3 ml; 2x30 sec" to meet the EN 1500. Considering the length of the 60-seconds period in practice, raising the alcohol ratio should be considered in order to provide adequate hand antisepsis in 30 seconds.