Hand Sanitiser: how long am I protected for?
This article looks at the myths and misconceptions around hand sanitisers
Hand sanitiser doesn't last as long as you may think
Hand sanitiser isn’t perfect. And, it may surprise you to know that it doesn’t provide long-lasting protection. That’s contrary to what many people believe: more than half think that hand sanitisers last longer than they really do.
Sanitisers don’t work to protect you long-term and washing your hands at the sink is actually the best and first choice. “Alcohol-containing hand sanitizers are a convenient alternative to soap and water. The idea is that when a sink is not available, you use the gel,” says Philip Tierno, PhD, a clinical professor in the department of pathology.
Whereas washing your hands literally washes germs down the drain, “hand sanitisers kill whatever is on your hands at that moment,” says Michael Lin, MD, associate professor in the division of infectious diseases; “If you touch something else contaminated, you need to clean your hands again. The same goes for soap and water,” he says.
Neither keeps your hands clean longer than a couple of minutes. “As soon as you’re done washing or using a gel, there is no residual effect. You can re-contaminate your hands right away,” says Tierno. That happens as soon as you touch common (and often grimy) surfaces, like banisters, elevator buttons, or counters.
"So, before eating or drinking or touching your face for any reason, you’ll need to either wash with soap and water or use a hand sanitiser", says Tierno. "Doesn’t matter if you just washed up 30 minutes ago—do it again now". He adds that if your hands are dirty and you don’t have sanitiser on you, just wait to touch your face.
When using a hand sanitiser, choose one with at least 70 percent alcohol, cover all surfaces of your hands and rub them together until they feel dry.
Alcohol-based hand sanitisers may be preferred because of their convenience, portability, and quick-action effectiveness, but remember these gels or sprays do not work as well if your hands are visibly dirty.
To wash properly, the NHS advises generously lathering hands with soap for 20 to 30 seconds, making sure to get in between fingers and the backs of your hands. Don’t forget to get under your nails by scraping your nails on the opposite palm