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 handwash or HCW handwash products.27 The antiseptic activity of alcohols is attributed to their ability to denature proteins.28 Alcohol solutions, 60-95% (expressed as percent by volume) are more effective than 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 handrub (Figure 2) removes or destroys transient microorganisms and reduce the resident hand flora.1,25 Based on available evidence, the FDA, the CDC, and the WHO concluded that alcohol-based handrub is more effective than plain and antiseptic soaps and water (see Table 3) for HCW handwash.1,25,27 Alcohol-based hand antisepsis is indicated for routine hand hygiene in clinical situations when the hands are not visibly soiled.1,25 When performing alcohol-based handrub, follow the manufacturer’s recommendations regarding the volume of product to use. Liquids, gels, or foam formulations are all acceptable. The concomitant use of an alcohol-based handrub and an iodophor-based antimicrobial soap is contraindicated.
The frequent use of alcohol-based hand-rubs can cause skin irritation and dryness (irritation contact dermatitis) unless emollients, humectants, or other skin-conditioning agents are added to the formulation (solicit information from manufacturers regarding any known interactions between hand hygiene products, skin care products, and the type of gloves used). Formulations with strong fragrances may be poorly tolerated by HCWs and patients with respiratory allergies. Allergic contact dermatitis or contact urticaria syndrome to alcohols or to various additives present in certain formulations is rare.29,30 Contamination of alcohol-based products is remote.31 Alcohol-based hand rubs are flammable and should be stored away from high temperatures (flash points range from 210C to 240C) or flames.32