Other Antimicrobials: Alcohol

Alcohol, a term used generically, may describe isopropyl alcohol, ethyl alcohol or propanol. Alcohols have shown great in vitro efficacy against Gram-positive bacteria, Gram-negative bacteria (including multidrug-resistant pathogens such as MRSA and VRE) and fungi. Alcohol has also been tested in vitro against enveloped viruses such as herpes simplex virus (HSV), human immunodeficiency virus (HIV), influenza virus, respiratory syncytial virus (RSV) and the vaccinia virus; in concentrations of 60-80%, it has shown efficacy against hepatitis B virus (HBV) and hepatitis C virus (HCV).24 Alcohol has a rapid onset of action when applied to the skin, and it has demonstrated a 3.5-5 log reduction of bacteria when applied to the skin.24

Alcohol molecule

Alcohol Molecule

Mechanism of Action

Alcohol's antimicrobial activity is due to its ability to denature proteins. The ideal alcohol solution is of a concentration ranging from 60-80%. Higher concentrations of alcohol or alcohols in their pure form are less potent as an antimicrobial since proteins do not denature well in the absence of water.24

Uses

Alcohols are often used for skin antisepsis (disinfecting pads and surgical patient preparation solutions (alone or in combination with other antimicrobial agents)), in waterless hand hygiene products, surgical scrubs solutions and hard surface disinfectant.29

Limitations

Alcohol is not recommended alone for hand hygiene when the hands are visibly dirty. Alcohol has excellent germicidal properties, yet little or no residual antimicrobial activity on the hands.24 It is for this reason that alcohol is often combined with other antimicrobials such as chlorhexidine for a synergistic residual antimicrobial effect.12 Alcohol has shown virtually no activity against spores and sporozoan oocysts and poor activity against some non-enveloped viruses. Alcohol is flammable, and it must be used safely.24 Alcohol is not recommended for sterilization of medical devices and surfaces since it is not sporicidal.1