What is the recommended dilution for chlorhexidine when preparing a surgical scrub solution?

• A. 50:50
• B. 1:100
• C. 1:10
• D. 1:5

Answer: (A)

The main idea here is achieving a suitable antiseptic concentration for a surgical hand scrub. For chlorhexidine, a commonly effective final concentration for scrubs is around 1%. To reach this from a typical stock solution, mixing equal parts chlorhexidine with sterile water (a 50:50 dilution) halves the stock concentration. So if you start with a 2% chlorhexidine solution, a 50:50 mix gives about 1% in use, which is a standard target for scrubs.

Other dilutions would yield far lower concentrations (for example, 1:10 or 1:5 would produce around 0.2% or 0.4% if starting from 2%), which may reduce antimicrobial efficacy. A 1:100 dilution would be too dilute to be reliably effective. Therefore, the equal-volume dilution is the practical choice to achieve the desired 1% final concentration for a surgical scrub.