The major hazard of napalm is that it contains gasoline.  It is, however, less flammable than gasoline and therefore less hazardous.  Napalm is harder to ignite than one would expect.  With some forms of modern day napalm, you could throw a grenade into it and it wouldn't ignite.  Thermite is usually used to ignite napalm which burns at 4532^oF.  A match or even a roadflare will not ignite napalm.  The more polystyrene inside the mixture, the harder it is to ignite.