We all know that you shouldn’t leave your kids or pets in the car on a hot day, but what about hand sanitizer?
Over the last few days a story has gone viral about a fire department in Wisconsin that warned not to leave hand sanitizers in hot cars because it can spontaneously combust. The image they shared was that of a car that caught fire after hand sanitizer was exposed to a flame in Brazil.
Hand sanitizer has a flash point around room temperature but that doesn’t mean that it will spontaneously catch fire if it reaches close to that temperature. Flash point is a term that is used to describe the point when a liquid gives off enough vapor that it is ignitable in the air. You still need an ignition source, such as a flame from a lighter.
Spontaneous ignition involves a substance that self heats to the point where it ignites without any outside ignition source such as a lighter.
Hand sanitizer will not self heat and requires temperatures over 370 Celsius to spontaneously ignite. The one thing you should be aware of is that hand sanitizer being exposed to high heat for a long period of time may reduce it’s effectiveness, but it won’t catch fire.
What have we learned? Hand sanitizer gives off vapors that can ignite around room temperature. Those vapors still need to be exposed to something like a flame to ignite. Hot cars will not ignite hand sanitizer.