 These flares, known as "pyrophoric flares", are made of special materials that ignite when they come in contact with the air.This is a safety and convenience factor, since attempting to ignite a flare inside the fuselage and then deploying it is risky.However "pyrotechnic flares" (such as the MJU-32) also exist, and offer their own safety benefit; requiring an external ignition method, an accidental leak or puncture in the storage compartment would not result in a catastrophic fire on board the aircraft as with a pyrophoric flare.