Antibacterial Hand Sanitizer Vs. Hand Soap

Nowadays it is common to have antibacterial hand gel, often alcohol-based, available in shops, in schools, in hospitals and at home. The purpose is to block the spread of microorganisms that cause disease, especially gastrointestinal and respiratory illnesses. It's hard to decide whether that is more effective than ordinary hand washing with soap, unless you examine the scientific evidence.

How Soap Works

Soap is made from sodium hydroxide and fat, forming soap molecules. Soap molecules have a long chain of hydrocarbons and a cap at one end of sodium and oxygen. The hydrocarbon chain is non-polar and is attracted to oils and grease. The polarized cap of the soap molecule attracts water. The hydrocarbon chain attaches to the oils and dirt, and the water-loving cap of the molecule suspends the dirt and oil in water. It works better in alkaline water than in acid water, and better with hot water than cold water.

How Hand Sanitizers Work

Alcohol kills bacteria and hand sanitizers contain alcohol, so they kill bacteria on the surface of your hands. The alcohol penetrates the cell membrane of the bacteria and renders it inert. If you rub enough of the alcohol over your hands for a long enough period, you will destroy most of the bacteria on your hands.

Expert Insight

According to the authors of a study published in "Applied and Environmental Microbiology," hand sanitizer was relatively ineffective in reducing Norwalk virus on the human hand. Another study, reported in "Pediatrics," showed using an alcohol-based hand sanitizer and disinfecting surfaces in the classroom significantly reduced gastrointestinal illness in students, but had no effect on the rate of respiratory illnesses. A study reported in "Pediatric Nursing" reported no difference in absentee rates between children who washed with soap and water and children who washed with an alcohol-based hand sanitizer. A study conducted in Dar es Salaam, Tanzania where there is a shortage of water, reported in "The American Journal of Tropical Medicine and Hygiene," demonstrated that hand sanitizer was significantly better than hand washing in reducing levels of fecal streptococci on the hands.

Conclusion

In the "International Journal of Food Microbiology," in an article on hand washing efficacy, the authors concluded that taking off your rings, washing with antimicrobial soap and drying with paper towels was the most effective procedure. Hot air drying resulted in a small increase of contamination on the hands as did touching the water spigot with bare hands.

Notes

Antibacterial hand soap is effective against the transmission of respiratory illnesses, but not gastrointestinal illnesses. It is effective where water is not available for hand washing, but not effective for cleaning dirt off your hands. It is not effective when your hands are frequently exposed to water, as in a kitchen.

When you use antibacterial hand sanitizer, use enough to completely wet your hands and keep them wet while you rub your hands together for 20 seconds. When you wash your hands with soap, use warm water, antimicrobial soap and scrub your hands for at least 30 seconds before rinsing. Dry with disposable paper towels.