Hand sanitizer vs soap, what does science have to say?


There is a a heated debate regarding traditional hand washing methods and newer waterless hand sanitizer.  There are passionate supporters on both sides of the argument, but what does the research show?  Let science!

Yes, let us science

A good way to measure which method is more effective is to look at its’ impacts in the real world. Several studies consistently report around a 30% decrease in hospital infections with easy access to alcohol based sanitizer. But it’s not all on the hands of the caregivers: a study done in a large hospital found that simply giving patients alcohol-based sanitizer and educating them on their benefit had a 36% decrease in infections in the urinary tract and at surgical incision sites as well. Simply installing gel sanitizer stations in dorm rooms and dining halls in the University of Colorado Boulder campus resulted in up to a 40% improvement in upper respiratory infections like the flu and colds.  One study found that using gel sanitizer decreased sick days in children 5-12 by one-third.

What about sanitizer compared to hand washing? A very large study from the Journal of the American Medical Association found no difference in infection rates in a neonatal unit between hand washing and sanitizer.  Another study of 18 second and third grade classrooms found no significant differences in illness rates between the two, only that school nurses preferred the hand sanitizer.

Looking at actual germ counts, research found alcohol based sanitizer to be significantly more effective at reducing bacteria populations than hand washing with soap.  It took 4 hand washes with antiseptic soap to reduce the bacteria as much as the sanitizer did. The British Medical Journal confirmed that alcohol based sanitizer decreased bacteria on hands 26% better than the proper hand washing technique of 30 seconds. Using sanitizer numerous times in a day does not make it less effective. There is no difference in effectiveness between gel, foam or wipe forms.  The Center for Disease Control recommends sanitizer made of at least 60% alcohol. Gels with the antimicrobial agent Triclosan were popular in the past, but are being phased out due to environmental concerns.

Based on the review of many studies over several years the International Journal of Nursing Practice came to the conclusion that: “alcohol-based hand rubbing removes microorganisms effectively, requires less time and irritates hands less often than does hand washing with soap or other antiseptic agents and water. Furthermore, the availability of bedside alcohol-based solutions increases compliance with hand hygiene among health care workers”.


Yes you do!

Convenience is key. A very large study from the Journal of the American Medical Association saw hand hygiene compliance rates double from hand washing alone when alcohol based sanitizing stations were placed outside of patients’ rooms in a hospital. Doctors are actually worse about hand hygiene than nurses. Visitors to the ICU washed their hands 20% more than staff!  Access to sinks is another reason many people have poor compliance with traditional hand washing. Time is a major factor in convenience; proper hand washing takes on average 8 times as long than use of waterless sanitizer. Washing with soap is more than inconvenient, it has been shown in several studies to significantly cause more dryness and irritation to hands than gel sanitizer. However not all healthcare workers prefer sanitizer; hand washing is preferred by 71% of dentists.

Fight fingernail grime responsibly

Hand washing does win in some areas.  Washing with soap and water was more effective at decreasing bacteria under the fingernails.  Many dangerous bacteria and fungi including yeast can live under the nails.  Proper nail care is essential to hand hygiene. Use of a nail brush with hand washing has the greatest impact on these dangerous organisms.

Soap is always recommended if the hands are visually soiled such as with dirt or food.  The friction of rubbing the hands together will loosen the contaminant. Soap works by mixing with the dirt and bacteria so that water washes it away off of the hands.  If hands are already moist such as working with food, hand sanitizer is not as effective.  Alcohol based sanitizer work by actually killing the virus and bacteria.  If the hands are moist or oily they cannot reach the bacteria and cannot be as effective.  Hand washing is preferred in the food industry because of this.  Also, if it is not left to dry long enough before handling food, leftover gel can get into the food and contaminate it. While sanitizer is good for your hands, it is not good for your stomach!

Hand sanitizer are not effective against all microorganisms. Clostridium difficile is a dangerous bacteria which causes extreme diarrhea and is usually only seen in hospitals.  If a patient has a C. diff infection warning signs are placed on the door advising staff that they must wash hands with soap and water as sanitizer is ineffective. Staff and visitors must also wear special gowns to enter the room to prevent the spread of infection.  C. diff infections are not common outside of hospitals and are easily diagnosed so proper infection control is initiated completely.

World Health Organization’s proper hand washing technique

Adequate hand washing techniques are not common.  Proper technique involves many steps and 20-30 seconds.  A study found only 26% of college students sufficiently washed their hands. and only 30% of food workers. Improper hand washing can actually increase bacteria on the hands. There can be significant amounts of microorganisms on the faucets and paper towel dispensers as well. Hands free electric dryers decreased the most bacteria versus paper towels, but hands free towel dispensers were safer than those that had to be touched.

Although I have always been biased to alcohol based sanitizers due to their convenience (and you can get ones that smell pretty, thanks Bath and Body Works!), I approached the situation with an open mind and the research was clear. Based on the clinical evidence research I performed I have come to the following conclusion.

Alcohol based hand sanitizer is more effective in reducing microorganisms on hands, less harsh on hands and more convenient therefore increasing compliance. However traditional hand washing is preferred when hands are visibly soiled or moist, in the food industry and when in contact with someone with C. diff.

Thanks Khloe!

Tune in next time when we science again!




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