Hand sanitizer (also known as hand antiseptic, hand disinfectant, hand rub, or handrub) is a liquid, gel or foam generally used to kill many viruses/bacteria/microorganisms on the hands.It can also come in the form of a cream, spray, or wipe.In most settings, hand washing with soap and water is generally preferred. Hand sanitizer is less effective at killing certain kinds of germs, such as norovirus and Clostridium difficile, and unlike hand washing, it cannot physically remove harmful chemicals. People may incorrectly wipe off hand sanitizer before it has dried,[ and some are less effective because their alcohol concentrations are too low.