9 Mistakes That Make Hand Sanitizer Less Likely to Kill Germs

Many of us have developed a newly intense relationship with hand sanitizer over the past year or so. Now, it's a daily use item — as essential when leaving the house as our phone, wallet and keys.

There's good reason to turn to hand sanitizer.

"Hand hygiene helps prevent the spread of infection," says Jose Raymond M. Mercado, MD, associate hospital epidemiologist at Dartmouth-Hitchcock Medical Center in Lebanon, New Hampshire.

And using hand sanitizer is a cheap, convenient option, he says. Compared to washing your hands for 20 seconds multiple times a day, hand sanitizer causes less irritation, per the Michigan Department of Health. Plus, it's easy to use on-the-go when you're running errands that take you from the park to the grocery store to the gas station.

But the squirt-and-rub process only protects you if you pick up the right variety of sanitizer and apply it correctly. We spoke with experts to uncover some of the biggest hand sanitizer mistakes you may be making — and how to fix them.

The ingredient makeup — and the effectiveness — of hand sanitizers can vary. Look for options that have at least 60 percent alcohol, per the Centers for Disease Control and Prevention (CDC). These are the most effective at killing germs.

Avoid any hand sanitizer made with methanol and 1-propanol, which are potentially toxic forms of alcohol, per the U.S. Food & Drug Administration (FDA). You can see a full list of hand sanitizers that shouldn't be used on the FDA's website.

In the early months of the pandemic — that time period associated with stocking up on toilet paper and disinfectant wipes — there were hand sanitizer shortages. In response, some people opted for a DIY approach, using alcohol from the liquor cabinet to make their own. That's not recommended, per the FDA, which notes that mistakes in the process can render homemade hand sanitizer dangerous or ineffectual.

Don't be modest when squeezing out the sanitizer.

"I recommend adults use an amount of hand sanitizer that is at least the size of a quarter to rub on their hands," says Savita Ginde, MD, MPH, chief health care officer with Stride Community Health Center, which operates several health clinics in Denver.

Keep the quarter-sized amount in mind, but also consult the instructions on the bottle, since some will recommend using a smaller or greater amount. (Also, if you have very large hands, perhaps you'll need to opt for a bigger quantity.)

Not squirting out enough hand sanitizer leads to the next potential problem.

When you scrub with soap and water, you wash your whole hand — in between the digits, as well as the palm ​and​ back of your hand. Aim for the same level of thoroughness when applying hand sanitizer.

Your goal: "[Use] enough to adequately coat and cover the front and back of the hands, as well as the fingers and the area in between the fingers," Dr. Ginde says. If you just rub your palms together, you're not completing the task.

If you think of using hand sanitizer as being a faster option than washing your hands with soap and water, that's not entirely correct. You want to rub the hand sanitizer in for about 20 seconds, per the Mayo Clinic.

If that 20-second rule sounds familiar, that's because it's the same amount of time you should take to wash your hands with soap and water. (By the way, that length of time is about how long it takes to since the "Happy Birthday" song twice over.)

That wet feeling of hand sanitizer sinking into your skin can be unpleasant. Still, resist any temptation to dry off your hands using a towel or your pant leg. Doing so "could dilute the effectiveness of the hand sanitizer," Dr. Ginde points out.

Plus, if you have germs on your pant leg, you'll have just contaminated your hands, she notes.

"In an ideal scenario, you want to rub your hands until the hand sanitizer dries off instead of wiping them," Dr. Mercado says.

Can you leave your hand sanitizer in the car for easy access? That depends on the climate where you're driving.

Hand sanitizer should ideally be stored between 59 and 86 degrees Fahrenheit, according to the FDA. The FDA also cautions to avoid freezing temperatures or extreme heat (over 104° F). So if your car will reach a frigid or steamy temperature once the engine is off, you may be better off bringing it along.

Keeping hand sanitizer at room temperature is your best bet, Dr. Ginde says.

Hand sanitizer can do a lot, but when your hands are visibly dirty, it doesn't work as well.

"Anytime your hands are heavily soiled or greasy, the hand sanitizers may not work as well as you washing your hands in soap and water," Dr. Mercado says.

So after you fix the chain on your bike or spend some time weeding in the garden, head to the sink if possible.

"If that is not immediately available, use hand sanitizer and make a mental note that your hands are still not clean so you want to make sure you don't touch your face, eyes, nose, mouth," Dr. Ginde says. "Also, make note that whatever you touch with those hands — such as your phone, steering wheel, door handle — will all need a sanitizing wipe-down the first chance you get."

Even if you follow all these steps, you need to use hand sanitizer — or wash your hands — at key moments in order to ensure proper hand hygiene. Here's when the CDC recommends cleaning your hands (whether with soap and water or a glug of sanitizer):

• Before making or eating food
• After you use the restroom or change a diaper
• After touching or removing your mask (you should only touch your face with clean hands)
• When you blow your nose or cover your mouth while sneezing or coughing (you should use sanitizer even if you've coughed or sneezed into a tissue)
• After you're in a public place, such as the grocery store
• After you're in contact with pets
• After being in contact with people who are sick

Bottom line: There are a lot of moments in life that call for cleaning your hands.

"I can't stress how important it is to wash your hands with soap and water, or to at least use hand sanitizer, repeatedly throughout the day to protect yourself from germs and viruses," Dr. Ginde says.

Hand sanitizer is a great option. But it's not the only path to hand hygiene — nor is it necessarily the best option. For instance, soap and water is more effective than hand sanitizer against the germ behind the norovirus, per the CDC.

"If you are able to wash your hands with soap and water, I'd recommend that as the first choice," Dr. Ginde says. Soap and water ensures that all germs and viruses are removed from your hands, she says.