Q: How much hand sanitizer is necessary for cleaning your hands? A: Follow the directions on the hand sanitizer jar. Most will instruct you to use a quarter-sized amount. You need to cover all the surfaces of your hands, top , bottom, fingers, around your fingertips and fingernails, and rub about two inches up your wrist. Q: How do I use a hand sanitizer properly? A: Dispense a sufficient amount of hand sanitizer in your palm to completely cover all surfaces of your hands. Then rub hands until dry. Be sure to cover your hands back, in between your fingers and around your fingernails. Q: If the alcohol-gel hand sanitiser still smells, is it working? A: When a sanitiser dependent on alcohol has evaporated, the killing capacity has vanished and this typically happens very soon after application. Some brands of alcohol-based sanitary products contain powerful fragrances to try to give the user a sense of protection Q: How do the sanitizers with hands work? A: Sanitizers work for a virus by disrupting the outer coat of the virus including the novel coronavirus. They work for bacteria by disrupting their cell membrane. Hand sanitizers are successful if they contain at least 60 per cent of rubbing alcohol, according to the CDC. However, they are not effective against viruses that do not have these coatings, like the norovirus, which causes the stomach flu.