As noted in Table 2, the FDA TFM of 1994 classified ethanol, 60 to 95%, as a Category I agent, i.e., generally safe and effective for use in antiseptic hand wash or HCW handwash products.26 The antiseptic activity of alcohols is attributed to their ability to denature proteins.27 Alcohol solutions, 60-95% (expressed as percent by volume) are more effective that higher concentrations because proteins are not denatured easily in the absence of water. Although alcohols are not considered to have residual antimicrobial activity, microorganisms appear to reproduce slowly on hands after the use alcohol-based products (presumably because of the sublethal antimicrobial effect of alcohols) and microbial counts on hands after wearing gloves for 1 to 3 hours seldom exceed baseline values.1
Alcohol-based hand rub (Box 2) removes or destroys transient microorganisms and reduce the resident hand flora. Based on available evidence, the FDA and the CDC concluded that alcohol-based hand rubs are more effective than plain and antiseptic soaps and water (Table 3) for HCW handwash.1,26 Alcohol-based hand antisepsis is indicated for routine hand hygiene in clinical situations when the hands are not visibly soiled, i.e., (1) before direct contact with patients, (2) after contact with a patient's intact skin (e.g., when taking pulse or blood pressure; lifting a patient), (3) after contact with body fluids and excretions, mucous membranes, or nonintact skin, (4) after contact with inanimate objects (including dental equipment) in the immediate vicinity of the patient, (5) before donning gloves, and (6) after removing gloves.1,24