After a cough or sneeze, we quickly rub some ethanol-based sanitizer on our hands, assuming that all the germs and microbes have died. However, a recent study conducted in Japan showed contradictory results. It took as long as 4 MINUTES for the flu viruses to be killed. This is because their hands were still wet with mucus and flu viruses can survive longer on hands wet with mucus.
So, if you are using hand sanitizer to protect yourself and others from flu viruses, you need to wait for as long as 4 minutes to be fully safe that germs have died, or first dry your hands from mucus and then apply hand sanitizer, in which case, it would take lesser time (two minutes or lesser).
Or best is follow the Center for Disease Control and Prevention (CDC), USA guidelines, when you sneeze next:
1. Wet your hands with clean running water and apply soap to a lather
2. Scrub all surfaces: palms, backs, fingers, between fingers, under nails
3. Scrub for 20 seconds (that’s the time it takes to sing ‘Happy Birthday” twice)
4. Rinse under clean, running water, dry hands with clean towel or air dry.
Dr Sudhir Kumar MD DM