Aerosols are designed to disperse a range of products including insecticides, pesticides, paints, cleaners and lubricants. They are usually pressurized with a variety of hydrocarbon propellants, from carbon dioxide to butane or propane.
Aerosol cans can explode when exposed to heat or if the container is compromised. This can result in serious injury or death.
Unlike a petrol can, which is filled with gas and can only burst if it is heated, most aerosol cans are liquid and will vaporize when subjected to heat. This is because the liquefied gas expands under heat and creates more gas pressure than the can is able to contain.
It can also happen if an aerosol is sucked up by a forceful blow, or if the seal is damaged or broken. The contents of an aerosol can will vaporize and the pressure inside the can increases, leading to an explosion.
A fire investigator teaches firefighters across the world to use fire behavior as a tool. For his demonstrations, he uses an abandoned Firestone dealership garage in Coon Rapids, Minnesota, to demonstrate just how dangerous a single aerosol can can be.
He explains that most aerosol cans contain between three and five ounces of butane or propane. That’s enough to cause a flame to follow the fuel and light it. It’s why he cautions that aerosol cans should never be placed on the grill of a car, or thrown in a fireplace or burn barrel.