Many years ago, butane was used as the propellant in most aerosol cans - during my misspent youth, much fun was had making flame-throwers out of cans of hairspray. Subsequently, manufacturers replaced the propellant, with a chemical that unknown to them, damaged the ozone layer � (CFC�s), but did not combust.
I haven�t bothered to look at what they now commonly use as a propellant � but either we will all die because of a hole in the ozone layer � or some spotty youths will die as a result of playing with fire (I just got lucky).