Handwashing is defined as washing hands with plain soap (esterified fatty acids and sodium or potassium hydroxide) and water, i.e., a detergent that does not contain an antimicrobial agent or contains low concentrations of antimicrobial agents that are effective solely as preservatives. The cleaning activity of plain soap is attributed to its detergent properties, which result in removal of dirt, soil, and various organic substances from the hands.
Handwashing (Box 1) removes loosely adherent transient microorganisms.1 It is indicated when (1) hands are visible dirty or contaminated with proteinaceous material, or are visibly soiled with blood or other potentially infectious material, (2) before eating, (3) after using a restroom, (4) after caring for patients colonized with Clostridium difficile, (5) following suspected or proven exposure to Bacillus anthracis (the physical action of washing and rinsing hands under such circumstances is recommended because alcohols and other antiseptic agents have poor activity against spoors), and (6) as part of two-stage surgical hand antisepsis, i.e., handwashing followed by the application of an alcohol-based hand scrub.1,24