How effective are hand antiseptics for the postcontamination treatment of hands when used as recommended?

We investigated the efficacy of 2 different volumes of 4 marketed hand rubs when applied to contaminated hands. Hands of 16 volunteers were contaminated with Serratia marcescens. Hand rub A (85% ethanol), hand rub B (60% ethanol), hand rub C (62% ethanol), and hand rub D (61% ethanol) were applied as blinded formulations, each in single applications of 2.4 or 3.6 mL. Hibiclens (4% chlorhexidine gluconate) served as the reference treatment. Each hand rub was rubbed into the hands until dry. Pre-intervention and post-intervention bacterial populations were obtained by the glove juice method. Neutralization of residual activity was validated. The results indicated that hand rubs applied in amounts sufficient to cover both hands may not reduce the bacterial density by even 2 log10 steps. Based on our findings, the general trend toward alcohol-based hand rubs should not overlook evidence of significant differences in efficacy that appear to be related primarily to a product's overall concentration of alcohol. AJIC. 2008;36(5):356-60.