Hands are the parts of our body that have the most contact with other people, objects, and our own selves — think about how often you mindlessly touch your face throughout the day. So while head-to-toe hygiene is a high priority for so many people, there’s an especially strong focus now on keeping hands clean when it comes to preventing the spread of disease-carrying germs.
Whether you’ve always got hand sanitiser handy or you prefer washing with soap and water, you’re already ahead of the game — both are far better at limiting the transmission of many viruses and bacteria than not doing anything to purify your hands. But is one approach more effective than the other? We spoke to medical experts to get to the bottom of which method is best for keeping germs at bay.
The pros and cons of hand sanitiser
Hand sanitiser has become a staple in purses, pockets, even on keychains — and for good reason. “Hand sanitiser can be more portable and accessible when people are on the go, which can increase the number of times they are able to disinfect their hands. This can help reduce the likelihood of transmitting viruses,” says Neha Nanda, medical director of infection prevention and antimicrobial stewardship for Keck Medicine of the University of Southern California.
Niket Sonpal, a New York-based internist, gastroenterologist, and adjunct professor at Touro College, agrees that it can often be the most convenient option: “The benefit of hand sanitiser is the ability to combat germs when water and soap are not immediately available.” Sonpal adds that hand sanitisers are effective at neutralising many microbes, viruses, and bacteria — but not all.
“Hand sanitisers are active against all types of viruses except norovirus, which causes a certain type of diarrhoea,” explains Linda Anegawa, a Hawaii-based internist with PlushCare. So while they definitely serve a useful purpose, they’re not a perfect prophylactic. “Sanitisers also don’t protect against some types of bacteria, including one called C. difficile, which causes diarrhoea from antibiotic overuse.”
Athanasios Melisiotis, a physician with Penn Medicine at the University of Pennsylvania, points out several other potential downsides of hand sanitiser: “Some hand sanitisers can leave a residue that feels slick or uncomfortable for some users,” he tells Allure, noting that hand sanitiser can also sometimes be more expensive than hand soap, which is the preference of each doctor we spoke to. “Hand sanitisers are great in a pinch and are more convenient, but soap and water ultimately are better.”
Why doctors prefer soap and water
Although many homes and businesses keep large pump bottles of hand sanitisers readily available, it’s best to think of hand sanitiser as a portable alternative when a sink and soap aren’t accessible. Why? “Viruses are most effectively killed and removed from hands with soap and water,” says Nanda.
“The consensus between the CDC and medical professionals alike is that the gold standard for maintaining hand hygiene is proper and consistent washing of the hands,” Sonpal tells Allure. That’s because soap and water are simply more thorough.
“Hand sanitiser may kill viruses and certain bacteria, but it does not ‘clean’ your hands like soap and water do,” Melisiotis says. “Sanitiser doesn’t remove actual dirt and debris. Soap kills germs, binds them, and helps physically remove them, with the water, off your skin and down the drain.”
It may seem like using an antibacterial soap would be the best of both worlds, and while it’s not a bad idea the jury is still out on whether or not it’s superior to regular soap. “Most soaps are sufficient. If you want to go the extra mile with antibacterial soaps you can, but according to the CDC studies have shown that there is no added benefit to using antibacterial soap over regular soap,” Sonpal says.
What to look for in a hand sanitiser when soap and water aren’t available
If your only option is hand sanitiser, make sure the one you’re carrying is actually up to par. That means checking the ingredients. “When water and soap are not immediately available, hand sanitisers with upwards of 60 percent alcohol are good second alternatives,” Sonpal says. Anegawa concurs, noting that the FDA recommends consumers look for up to 95 percent ethanol or isopropanol.
“Avoid ‘alcohol-free’ sanitisers as there isn’t much data on those and they can vary in effectiveness. We know that alcohol kills viruses,” Melisiotis says. “Don’t create your own hand sanitiser, though. You should buy quality-controlled and tested products that provide effective sanitation.”
Michael Chang, an infectious disease specialist with UTHealth at the University of Texas in Houston, says there are some hand sanitisers with an ingredient called benzalkonium chloride, which has been shown to reduce bacteria and viruses, but not as much as alcohol-based sanitisers. “Interestingly, benzalkonium chloride is active against norovirus, but for most respiratory viruses, like seasonal flu or this new [COVID-19 coronavirus], the alcohol-based hand sanitisers are preferred.”
Another reason to stick to alcohol-based hand sanitisers: “Since the alcohol in the sanitiser serves as a preservative, it’s less likely to be contaminated than alcohol-free sanitisers,” Chang tells Allure, noting that the World Health Organization (WHO) classifies alcohol-based hand sanitisers as an essential medicine.
Anegawa also warns against the inclusion of another common ingredient: triclosan. She says it’s believed that this particular antibacterial agent can reduce the effectiveness of a hand sanitiser and may even contribute to bacterial resistance.
No matter which you use, the technique is critical
Whether you use soap and water or a hand sanitiser, you might as well be using nothing if you’re not adhering to the correct methods. “The type of soap used is less important than the way hands are washed,” Nanda says. Every expert we spoke to insisted on scrubbing with soap and water for at least 20 seconds — Chang even insists on a minimum of 40 seconds — so a splash of soap on the palms followed by a nearly instant rinse isn’t going to cut it.
And you may be surprised to learn that the rules for properly using hand-sanitiser are even more stringent. “The CDC cites a three-step method: Apply sanitiser liberally, rub palms together covering all surfaces, and rub until hands are completely dry,” Anegawa explains. WHO guidelines expand upon the CDC’s second step, clarifying that hand-sanitiser users should rub their right palm over the back of the left hand with interlaced fingers (and vice versa), rub palm to palm with fingers interlaced, and rub the backs of fingers to the opposing palms with fingers interlocked.
“Alcohol-based sanitisers work by breaking down the germs, so not only do you have to have enough, the alcohol needs to hang around long enough to work,” Chang explains, recommending that you rub your hands with sanitiser until they fully air-dry. “That generally ensures enough exposure time. The exposure time really needs to be more than 20 seconds. If you only pump enough sanitiser so your hands are dry in 5 to 10 seconds, then that probably isn’t enough.”
But ultimately, Chang says, it comes down to actually doing it. “In the end, I usually say whatever you are most likely to do the most often, consistently, and correctly will be the most effective way to stop the spread of infection,” he advises. “Alternatively, why not do both?”