Hand sanitizer is being used a lot more these days, which has sparked some concerns.
As warmer months approach and the temperature rising, many are worried a bottle of hand sanitizer could ignite if left in a hot car, under the sun.
Although the alcohol inside the bottle is flammable, the ignition source must be an extremely high temperature.
"The ignition temperature of the alcohol is going to be around 700 degrees Fahrenheit, or 300 degrees Celsius," said Guy Colonna, Director of Technical Services at the National Fire Protection Association.
This means a flame would be able to ignite the sanitizer, however, a hot car would not.
For example, if the bottle is left on the seat of a car and is under direct sunlight, for it to start a fire, Colonna said the fabric and alcohol must have the same ignition temperature.
"The fabric has an ignition temperature which would be lower than the ignition temperature of the alcohol, or the hand sanitizer composition."
Colonna added spontaneous combustion is not possible either, because the material inside the bottle cannot self-react and heat up on its own.