Is soap and water the preferred method for hand hygiene when hands are not visibly soiled?

From the Guidelines

No, when your hands are not visibly soiled, alcohol-based hand sanitizers are actually the preferred method for hand cleaning in most healthcare settings. While soap and water is effective, alcohol-based hand sanitizers are more convenient, require less time (20-30 seconds versus 40-60 seconds for handwashing), cause less skin irritation, and can be more accessible at the point of care. Hand sanitizers with at least 60% alcohol can quickly reduce the number of microbes on hands in many situations, as recommended by the CDC and the Healthcare Infection Control Practices Advisory Committee 1. However, soap and water remains the preferred method when hands are visibly dirty, after using the restroom, when caring for patients with certain infections like C. difficile (as alcohol is not effective against spores), or after known or suspected exposure to certain pathogens. The effectiveness of alcohol-based sanitizers is due to their ability to denature proteins in microorganisms, while soap and water works by physically removing microbes through mechanical action.

Some key points to consider when choosing between soap and water and alcohol-based hand sanitizers include:

• The visibility of soil or contamination on the hands: if hands are visibly soiled, soap and water is preferred 1
• The type of patient care being provided: for example, when caring for patients with certain infections like C. difficile, soap and water is preferred 1
• The accessibility of hand hygiene facilities: alcohol-based hand sanitizers can be more convenient and accessible at the point of care 1
• The potential for skin irritation: alcohol-based hand sanitizers can cause less skin irritation than soap and water 1

Overall, the choice between soap and water and alcohol-based hand sanitizers depends on the specific situation and the individual's needs. However, alcohol-based hand sanitizers are generally the preferred method for hand cleaning in most healthcare settings when hands are not visibly soiled.

From the Research

Hand Hygiene Methods

When hands are not visibly soiled, the preferred method to clean hands is soap and water. However, in certain situations, hand sanitizers can be used as an alternative.

• The Centers for Disease Control and Prevention (CDC) recommends using alcohol-based hand sanitizer products that contain at least 60% ethyl alcohol (ethanol) or 70% isopropyl alcohol (isopropanol) in community settings 2.
• A study published in the Saudi Pharmaceutical Journal found that a non-alcoholic hand sanitizer containing benzalkonium chloride (BKC) as an active ingredient can be a potential alternative to alcohol-based hand sanitizers, with low viscosity, high spreadability, and a pH of 6.3, which is less likely to cause skin irritation 3.
• Another study published in the Infection Control and Hospital Epidemiology journal compared the immediate and persistent activity of two hand hygiene products, ethanol (61% w/v) plus chlorhexidine gluconate (CHG; 1.0% solution) and ethanol only (70% v/v), and found that the ethanol plus CHG sanitizer was associated with significantly lower aerobic bacterial counts on hands of healthcare workers, both immediately after use and after spending time in ICU common areas 4.

Comparison of Hand Hygiene Methods

A systematic review and meta-analysis published in the BMJ Open journal compared the effectiveness of hand hygiene using alcohol-based hand sanitizer to soap and water for preventing the transmission of acute respiratory infections (ARIs) and found that:

• Soap and water versus control found a non-significant increase in ARI events (risk ratio (RR) 1.23,95% CI 0.78 to 1.93) 5.
• Sanitizer versus control found a significant reduction in ARI events (RR 0.80,95% CI 0.71 to 0.89) 5.
• Head-to-head comparisons of sanitiser and soap and water found mixed results, with some studies finding a significantly greater reduction in the sanitiser group compared to the soap group, and others finding no significant difference between the intervention arms 5.

Safety Considerations

It is essential to note that hand sanitizers can have safety risks, such as:

• Methanol poisoning, which can be fatal if left untreated, and can cause severe anion-gap metabolic acidosis, seizures, and blindness 2.
• Ethanol toxicity, which can occur upon ingestion of alcohol-based hand sanitizer products, particularly in persons with alcohol use disorder 2.