Importance of neutralizers in the stripping fluid in a simulated healthcare personnel handwash.

The Food and Drug Administration (FDA) healthcare personnel handwash procedure allows for the use of a non-neutralizing stripping fluid after washing with an antimicrobial handwash product. The antimicrobial in the handwash product can remain active up until the time of neutralization or plating. A modified healthcare personnel handwash procedure using a pigskin substrate and a 4% chlorhexidine gluconate handwash product was used to demonstrate the need for a neutralizer in the stripping fluid. When tests were run with and without neutralizers in the dilution blanks, but with adequate neutralizers in the stripping fluid, there were no significant differences (p greater than .05) between results obtained after five washes or after each wash. When tests were run with a non-neutralizing stripping fluid, significant differences were noticed in the first and the fifth wash (p less than .05), and in the presence or absence of neutralizers in the dilution blanks (p less than .05). The data generated indicate that in order to determine the true activity of an antimicrobial handwash product, an adequate neutralizer should be incorporated into the stripping fluid and not just the dilution media. They also suggest that neutralizer carry-over from the stripping fluid is not a valid concern.