Summer is here, but one thing hasn't changed: we still need to do our part to prevent the spread of the novel coronavirus. Toting hand sanitizer around has become the norm and, for many people, that includes keeping an extra bottle in the car. But is that habit safe as the temperatures rise? Could the heat render the hand sanitizer ineffective?
While you may have seen rumors circulating on social media that hand sanitizer can "explode" in a hot car, you won't end up with a fire on your hands if you keep a bottle stashed away. "For hand sanitizer to explode, the temperature would have to reach almost 700 degrees Fahrenheit to start a fire," Kathleen Dass, MD, at the Michigan Allergy, Asthma and Immunology Center, told POPSUGAR. "Even at the hottest temperature over the summer, studies show the maximum temperature most cars will reach is 160 degrees."
However, you should avoid leaving hand sanitizer in direct sunlight in a hot car. Hand sanitizer needs to have at least 60 percent alcohol content to be effective. "Prolonged heat and sunlight exposure can make the hand sanitizer less effective because the alcohol can evaporate," Dr. Dass said. She also noted that having sanitizer in a clear bottle can raise the temperature. Jeffrey Toll, MD, an internal medicine physician in Los Angeles, told POPSUGAR that in order to avoid any potential degradation of the sanitizer's quality, you should keep it away from direct sunlight if you're in the car for a long period of time.
Although keeping hand sanitizer in a hot car won't cause a fire, Dr. Toll said it's important to remember that it is flammable — because it contains alcohol — so you should always be mindful of where you store it and make sure to keep it away from any open flame. Dr. Dass added that when storing it in your car, make sure it's not anywhere near the car's cigarette lighter. But purely for COVID-19 purposes, the most important thing is to keep it in the coolest space possible. "Store it in a cool, shaded, or partially shaded place in your vehicle," Dr. Toll said. "And remember that it is not a replacement for soap and water, just an alternative to use when soap and water are not available."