everyone always means well. i just thought propane wouldnt b that dangerous.  it can leak, but how is it going to ignite?  no spark.  its all contained in teh engine.  plus propane needs O2 to ignite, it wont light by itself.  just trying to get info here, not arguing one way or the other.

All it takes is a misfire from a spark plug, an accident which damages the condensor (since colliding metals may spark). Sure the argument could be made,"what about gas tanks?"  Gas tanks aren't mounted in the front most of the vehicle for this reason. But of course, nothing is perfect, I know. 

 Not all the components are in the engine compartment. The evaporator core is in the dash. I don't know if you smoke or not but if it should leak and you might be smoking or someone else is smoking or even just a flick of a lighter, for example. Sure probably small odds but possible.

O2 is everywhere, just not in pure form and it is enough to sustain combustion. If that were not true propane grilles and stoves every where would be worthless. 

Most importantly it has already been proven with the off brand refrigerants as I mentioned earlier.  I just wanted for no one to have such a possibility of getting hurt by this means. That's all.