Content area
Full Text
An increasing awareness of the role of contaminated environmental surfaces in transmission of healthcare-associated pathogens has highlighted the need for effective methods for cleaning and disinfecting inanimate surfaces.1–6 Although excellent reviews of disinfectants used in health care are available,7–9 in the last 20 years, comprehensive reviews of individual disinfectant agents have been provided for only sodium hypochlorite and quaternary ammonium compounds.10,11 Because alcohols and alcohol-containing disinfectant products have been used for many years, the purpose of this article is to review the use of alcohols as disinfectants in healthcare settings.
The nomenclature used to describe alcohols can be somewhat confusing. Variations in the names given to the 3 types of alcohol used most commonly in healthcare include (1) ethyl alcohol or ethanol; (2) isopropyl alcohol, isopropanol, 2-propanol, or propan-2-ol; and (3) n-propanol, 1-propanol, or propan-1-ol. In the United States, “rubbing alcohol” usually contains 70% isopropyl alcohol. N-propanol is used in health care more commonly in Europe than in the United States. Concentrations of alcohol solutions can be expressed as percentage by volume (% mL/mL or v/v), or percentage by weight (% g/g or w/w). For example, 70% ethyl alcohol (v/v) at 20°C represents 62.6% (w/w).12 In healthcare guidelines, alcohol concentrations are most frequently expressed as percentage by volume.13,14
Studies published in the late 1800s on the use of alcohols as disinfectants or antiseptics have been summarized by Price.15 One study in 1897 tested alcohol concentrations of 25% to 99% on silk thread and found 50% to be the most germicidal. Studies by Harrington16 exposed moist and dried silk threads contaminated with a variety of pathogens to 15% to 99% alcohol and found that 60%–70% was the most active against gram-positive pathogens (ie, Staphylococcus aureus). Price15 conducted in vitro tests using 3 pathogens exposed to 30%, 60%, and 70% alcohol (w/w) and found that 70% was the most effective after a 1-minute exposure, especially against S. aureus.
Subsequent in vitro suspension tests by Price17 revealed that 60%–90% ethyl alcohol concentrations were the most effective in 1 minute against three healthcare pathogens. In vivo studies by Price17 showed that 40% and 50% were significantly...