You’re standing in a grocery store hygiene aisle, facing a wall of liquid hand soaps. Some foam, others moisturize. Every plastic bottle promises a two-word aroma – crisp cucumber, warm vanilla. The soaps cost less than a dollar or as much as $10, but you just want something that will clean your hands.
When it comes down to that simple factor – how well soap cleans – the product you choose is much less important than how you wash your hands, and when, because common hand soaps are all powered by the same ingredients.
What you’re paying for in a plain soap are surfactants – a short term for “surface active agents,” or the ingredients that get harmful microbes off your skin and down the drain. Two common surfactants you’ll find are cocamidopropyl betaine and sodium laureth sulfate. Both are often combined with salt to contribute to that gelatinous quality in a pump of soap, according to Chris Boone, a technical expert at Univar Solutions.
Jim Arbogast, a vice president at Gojo Industries (the company that invented Purell), explained that the people tasked with formulating a good soap are trying to strike a balance: washing off the germs while leaving the “good stuff” for the skin. If the soap uses harsher surfactants, like you might find in some industrial cleaners or even dish soap, you’ll remove the germs, but your skin will feel dry after you rinse.
And removing germs doesn’t mean killing them; only hand sanitizers and antibacterial soaps do that. Hand-washing physically removes the bacteria, both when you rub your hands under the faucet and then when you dry them off with a towel, said Elaine Larson, a professor at the Columbia University School of Nursing. “The whole point of washing is to not kill the bacteria, just get them off your hands,” Larson said. “It’s such a simple thing, but I don’t think people realize it.”
The Centers for Disease Control and Prevention recommends using soap and water, but you can fall back on hand sanitizer if there’s no running water nearby.
At home, you don’t need the antibacterial soap found in hospitals, Larson said, or the fanciest, most expensive option. Plain soap gets the job done. Larson said the only reason to buy a top-of-the-line soap is for the experience – to make your hands smell or feel great. But don’t try to stretch your dollar by watering down a bottle of soap. Adding water to a soap can ruin the preservatives and contaminate the bottle. Bacteria may start to grow, and you could end up putting more germs on your hands than you had at the start, Larson said.
It should be noted: Your hands are often covered in bacteria. That’s normal. Put simply, “our skin is not sterile,” according to Laraine Washer, a professor for infectious diseases at the University of Michigan Medical School. We live in a homeostasis with bacteria.
The reason we wash our hands is to remove the harmful bacteria we come across, especially during cold and flu season, Larson said.
The concept of hand-washing was first presented by a Hungarian doctor named Ignaz Semmelweis. In the mid-1800s, Semmelweis recommended washing with a chlorine solution before interacting with patients. Some doctors found the notion offensive, because the recommendation implied that the doctors inadvertently infected patients.
We’ve come a long way since then, but chances are, you’re still washing your hands the wrong way. In a 2018 study from the Agriculture Department, 97% of people failed to properly wash their hands before a meal. Not surprisingly, Americans rush. The participants failed to spend 20 seconds washing their hands, the recommended amount of time from the CDC.
So, what’s the correct way to wash your hands?
1. Start with clean, running water. The temperature of the water doesn’t matter, according to a Rutgers study from 2017. Use what’s most comfortable.
2. Apply soap and lather your entire hand (not just your palm). People often forget their fingertips, according to Larson.
3. Clean your hands for 20 seconds. The CDC recommends singing “Happy Birthday” to yourself, twice. (Happy birthday!)
4. Rinse your hands and dry with a clean towel. The friction applied by drying goes a long way in physically removing any germs.
You don’t need to turn on the faucet every hour. The CDC advises washing your hands at key moments in the day, including while preparing a meal, after you sneeze or cough and after using the restroom. It’s better to build a habit around your daily life.
“It’s really about when, when you clean your hands,” Arbogast said.