You flush the toilet and turn to the bathroom sink to clean your hands. Both hand soap and water and waterless-hand sanitizer are available. Research suggests that both methods kill germs, but one method is better at killing the germs that lead to common viruses.

Benefits

Cleaning your hands with soap and warm water or hand sanitizer after using the bathroom is the single most important thing you can do to keep from getting sick and spreading illness, says the American Society for Microbiology, or ASM.

Frequency

Although the CDC recommends washing your hands or using hand sanitizer each time you use the bathroom, only 91 percent of Americans say they do so in public bathrooms, and only 83 percent were seen doing so in a study, reports the ASM 2. At home, people wash their hands a reported 83 percent. In a study cited by KidsHealth.org, only 58 percent of females and 48 percent of male students in middle school and high school washed their hands after using the bathroom 2.

Method

Wash your hands with soap and warm water each time you use the bathroom. Rub your hands together for 15 to 20 seconds, which is the equivalent of singing "Happy Birthday to You" twice. Rinse with water and dry by blotting your hands with a towel or rubbing your hands together under an air dryer.

When soap and warm water are not available, use a hand sanitizer with at least 60 percent alcohol content. Apply the sanitizer in the palm of one hand and rub your hands together, completely wetting both hands. Continue rubbing for 25 seconds or until your hands are dry.

Elementary School Study

A study by the Research Division of Woodward Laboratories in Los Alamitos, California, found that using alcohol-free hand sanitizer reduced illness and absentee days in elementary school students 3. All 420 students in the study heard a lesson on germs and the importance of hand washing 2. Students were divided into two groups and instructed to continue normal hand washing 2. However, the treatment group was also instructed to use hand sanitizer after using the bathroom, after coming into the classroom and before eating. Compared with the control group, the treatment group had 41.9 percent fewer illness-related absent days during the 10-week study.

Norwalk Study

The Center for Global Safe Water at Emory University in Atlanta, Georgia, found alcohol-based hand sanitizer less effective than liquid soap in killing the Norwalk virus. According to the FDA, The Norwalk virus causes viral gastroenteritis, acute nonbacterial gastroenteritis, food poisoning and food infection. Viral gastroenteritis is the second most common virus after the common cold. Hand sanitizer was deemed "relatively ineffective" at reducing genomic copies of the Norwalk virus on human finger pads.