Hand Hygiene Methods
Handwashing with Soap and Water
The purpose of routine handwashing in health care is to remove dirt and organic material, as well microbial contaminants, from the hands. Clean water must be used to prevent microorganisms in the water from contaminating the hands. However, water alone is not effective at removing substances containing fats and oils, which are often present on soiled hands. Proper handwashing also requires soap, which is rubbed on all hand surfaces, followed by thorough rinsing and drying.
The cleansing activity of handwashing is achieved by both friction and the detergent properties of the soap. Plain soap has minimal antimicrobial properties, but assists with the mechanical removal of debris and loosely adherent microbes, while the mechanical action removes some bacteria from hands. Time is also an important factor—handwashing for 30 seconds has been shown to remove 10 times the amount of bacteria as handwashing for 15 seconds. The entire handwashing procedure, if completed properly, as described step by step in Figure 1-2, should take 40–60 seconds. (CDC 2002; WHO 2009a)
Alcohol-Based Handrub (ABHR)
The antimicrobial activity of alcohol results from its ability to denature proteins (i.e., the ability to dissolve some microbe components) and kill microbes. Alcohol solutions containing 60–80% alcohol are most effective, with higher concentrations being less effective. This paradox results from the fact that proteins are not denatured easily in the absence of water; as a result, microorganisms are not killed as easily with higher alcohol-based solutions (> 80% alcohol). (WHO 2009a)
The use of an ABHR is more effective in killing transient and resident flora than handwashing with antimicrobial agents or plain soap and water. It also has persistent (long-lasting) activity. ABHR is quick and convenient to use and can easily be made available at the point of care. ABHR usually contains a small amount of an emollient (e.g., glycerol, propylene glycol, or sorbitol) that protects and softens skin. ABHR should be used at any of the “5 Moments” described earlier in this chapter, unless hands are visibly soiled. (CDC 2002; Girou et al. 2002; WHO 2009a)
To be effective, approximately 3–5 mL (i.e., 1 teaspoon) of ABHR should be used. The ideal volume of ABHR to apply to the hands varies according to different formulations of the product and hand size (refer to manufacturer’s instructions for use). ABHR should be used, following the steps shown in Figure 1-3, for approximately 20–30 seconds or until the solution has fully dried. Since ABHR does not remove soil or organic matter, if hands are visibly soiled or contaminated with blood or body fluids, handwash with soap and water. To reduce the buildup of emollients on hands after repeated use of ABHR, washing hands with soap and water after every 5–10 applications of ABHR is recommended.