Using hand sanitizer is a good backup if you can't wash with soap and water.
A recent study showed that alcohol-based gels lose their germ-killing power within two minutes of application -- a finding that took many consumers by surprise. But hand sanitizers were never intended to shield skin from incoming bacteria and viruses; rather, they're made to eliminate germs on contact, much like soap and water do, says Megan T. Sandel, M.D., a nationally recognized expert on both healthy housing and teen health. Dr. Sandel has been a practicing pediatrician at Boston Medical Center and Children's Hospital for more than 10 years.
To ensure your hand sanitizer is sufficiently potent, look for a brand that contains at least 60 percent alcohol. Just bear in mind that frequent hand cleaning -- whether with sanitizer or soap -- can dry out skin, creating tiny cracks that heighten the risk of infection. So be sure to moisturize regularly, as well.