How to Make Your Own Hand Sanitizer to Protect Against Coronavirus (Vodka Won't Cut It)

As the new coronavirus COVID-19 spreads throughout the United States—with cases confirmed in 16 states as of Thursday—demand has soared for hand sanitizer, resulting in empty store shelves across major retailers. In response, many are turning to recipes, spread on social media, for homemade variants. But is making your own hand sanitizer a good way to guard against the coronavirus?

Both the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) recommend hand sanitizer as a single component in a constellation of recommended prevention measures, with a special emphasis on hand washing.

"Wash your hands often with soap and water for at least 20 seconds or clean your hands with an alcohol-based hand sanitizer that contains 60 to 95 percent alcohol, covering all surfaces of your hands and rubbing them together until they feel dry," the CDC recommends, additionally pointing out that people often don't use enough sanitizer, or wipe it off before it's had a chance to fully dry and be as effective as possible.

But popular recipes spreading on social media for making your own hand sanitizer may not be up to the task, particularly if the alcohol used becomes too diluted by other ingredients. The most popular formulation involves mixing aloe vera gel with isopropyl alcohol (more commonly known as rubbing alcohol), but getting the right ratio can make the difference between an effective or ineffective sanitizer.

One popular recipe posted at a pharmacy in New York and shared across Twitter calls for one part isopropyl alcohol to four parts aloe vera gel. Unfortunately, this will dilute the alcohol to below the 60 percent threshold for efficacy. Better is a recipe that recommends two-thirds of a cup of 99 percent rubbing alcohol and one-third cup aloe vera gel.

Unfortunately, the ratio can vary, depending on the formulation of isopropyl available, so you'll have to perform a little math to ensure you're not diluting the rubbing alcohol below the 60 percent threshold.

But there's another popular recipe for homemade hand sanitizer that should be avoided entirely. While vodka and other alcoholic beverages have been poured on open wounds in movies and TV shows for decades, it's not an effective way to sterilize a surface. Most off-the-shelf vodka only contains 40 percent alcohol, making it an ineffective preventive guard against the new coronavirus.

Craft vodka maker Tito's has repeatedly affirmed that its vodka should not be used in coronavirus prevention:

While alcohol-based hand sanitizers can be effective at killing certain types of viruses, research suggests washing with soap and water is a more effective and preferable method. In its recommendations the CDC emphasizes that while alcohol-based hand sanitizers can reduce the presence of viruses on your hands, it is unlikely to eliminate all germs, particularly when hands are visibly dirty or soiled.

Newsweek has reached out to both the CDC and the WHO for additional details on making your own hand sanitizer and will update this article accordingly.