Most aerosols will ignite. Either the product or the propellant will be flamable. I worked for fifteen years for a company that made aerosol products and learned some scary stuff about them. With the knee jerk reactions by the Consumer Products Safety Commision, it's surprising that aerosols are even allowed to be sold in the U.S today.
You had to be near a production line when a defective can went through the machines that filled them. It was like the 4th of July in some cases.
As far as igniting the spray from a can: If you'd seen the results from tests where the can exploded, you wouldn't play around with that notion. DON'T DO IT!