How NOT to Formulate Hand Sanitizers


'There are two key formula types to consider,' David Steinberg, cosmetics industry veteran, consultant and formulating and regulatory expert tells us. 'You have the FDA Monograph-approved OTC 'instant' hand sanitizers, which are gels of foams like the Purell brand, and there are what's referred to simply as 'hand sanitizers' by the CDC, FDA and WHO.'

He explained that the instant hand sanitizers, meaning the gels, are required to use denatured ethyl alcohol—with the INCI "Alcohol" in the active ingredients listing and % v/v and denaturant listed in the inactive ingredients section—gelled with neutralized carbomer. These products must be U.S. Food and Drug Administration (FDA)-approved, and can contain added fragrance and other ingredients.

Supply Shortage

However, as we all know, supplies have run short. Production of the main carbomer used was increased in the U.S. but is still taxed to keep up with demand. Other sources, may have been shut down due to COVID-19. So as an alternative, the U.S. FDA has approved the selling of "hand sanitizers," which are thin liquids like water (and not as appealing to use).

"There are two forms of the liquid 'hand sanitizer' approved by the CDC," says Steinberg. "One is based on 80% ethyl alcohol and the other, 75% isopropyl alcohol." He adds these products contain the alcohol, glycerin, hydrogen peroxide and water—at the amount published by the FDA—and may contain nothing else. As an aside, he notes the OTC Monograph lists ethyl alcohol at 60% to 95%, and isopropyl alcohol at 70% to 91.3%.

"These sanitizer formulas must exactly follow the FDA labeling but marketers like to add fragrance and other ingredients." One recent example was a product with added CBD. "That's a drug and an illegal mixture, and is not allowed," Steinberg says. 

Also, these liquid hand sanitizers are less aesthetically pleasing. They do the trick immediately until they evaporate away but the alcohol can be extremely drying to skin. In FDA-approved gels, formulators can add humectants to help counteract this effect.

Microbreweries in Action

Besides shortages in carbomer, alcohol can be scarce. That's where microbreweries have been stepping in. By modifying their distillation process, they can make alcohol for use in hand sanitizer applications.

"Distillation for beverages like scotch and vodka typically produces a 40% alcohol, but breweries can adapt their processes fairly easily to create a higher proof and dilute it down with water," he says. "These breweries can then add the water, glycerin and hydrogen peroxide to create hand sanitizers."

On a cautionary note, however, distilleries must be careful because at these especially higher levels, the alcohol is very flammable. "On FDA labels for these products, we typically see a 'Caution: Flammable' warning. And we've already seen reports in the news of fires. One guy, for example, not thinking, lit a cigarette and a fire broke out," Steinberg says.

Besides breweries, larger companies like Dow and SC Johnson that have the right raw materials are combining the ingredients to make hand sanitizers for current demand. "The only thing I wonder, when this all is over (hopefully soon), is who will buy all these liquid hand sanitizers?" Steinberg notes.

There's so much confusion and so many warning letters have been sent. Hopefully this brief overview will prove useful.

More in Actives