Whether they dangle from keychains, spritz from pens or froth and pump out of clinic and classroom dispensers, hand sanitizers are convenient alternatives to handwashing, and they do work.
But when it comes to keeping germs away as we enter the cold and flu season, nothing beats a good scrubbing with soap and water.
Dr. Roland Newman II, a family medicine physician at Penn State Health, said being able to keep hand sanitizer in your car, bookbag or desk makes staying healthy in the cold months easier than ever.
"For the average person, they are super convenient, and I think they do have a place in hand hygiene," he said. They are also easier to use than ever. Some come pleasantly scented, while others add moisturizers to keep skin from drying out.
The trouble arises when users neglect traditional handwashing in favor of the alcohol-based concoctions.
Washing appropriately with soap and water can actually rid your hands of more germs and – depending on what you are coming in contact with – some chemicals."
Dr. Roland Newman II, family medicine physician, Penn State Health
For times when skin is really dirty or laden with grimy material, only a real handwashing will do.
Wet hands with water. Add soap. Cover all surfaces.
Most people know the basics. The key, Newman said, is to rub vigorously for about 20 seconds, or about how long it takes to sing "Happy Birthday" through twice or talk through the alphabet.
"What the soap does as you are scrubbing is release all the dirt and germ particles from the surface of the skin," he said. "They get bound up in the soap lather so when you rinse, all those germs and debris get washed away."
Cold, warm or hot – the temperature of the water doesn't matter. It's the length of time spent scrubbing and rinsing off appropriately that are key to a good handwash.
When that's not possible, turn to a sanitizer with alcohol content of 60 to 95 percent.
Newman cautions that because hand sanitizers are an alcohol-based product, they should be stored out of the reach of children and used by children only with adult supervision.
While the claims on most sanitizers saying that they kill 99% of bacteria and germs are true, Newman said some viruses can still sneak through: "Not all sanitizers are effective against norovirus and some healthcare-related bacteria."
Increased use of hand sanitizers has prompted some to question whether overuse can create problems with bacteria resistance. While it's a legitimate concern that is being studied and discussed, Newman said it comes up more with antibacterial soaps than with hand sanitizers.
"Sterility is not always better," he said. "Sometimes getting some exposure – as long as it's not life-threatening – can actually be adaptive and beneficial to our immune systems."