It’s hard to imagine the Fourth of July without fireworks, but experts warn that using hand sanitizer while handling sparklers can make a very dangerous and flammable combination.

Most hand sanitizers contain alcohol, explained Dee Shelton, fire and life safety educator with the Greensboro Fire Department in North Carolina, adding that people should be cautious not only near fireworks but also around any open flame such as a grill or campfire.

According to The Sacramento Bee, people using sanitizer should make sure their hands are completely dry before using fireworks or, better still, use soap and water to disinfect their hands instead. Hastings Tribune in Hastings, Nebraska, issued a safety warning that hand sanitizer is 87% alcohol-based and “extremely flammable.” Ron Pughes, the director of emergency management in Adams County, said that people should make sure to keep containers of hand sanitizers away from fireworks or other combustibles.

Shelton added that aside from the risks associated with the germ-killing sanitizers, handling fireworks presents its own risks of personal injury or property damage.