I'm no expert but my Uncle was, he always said he would quite happily chuck a lit cigarette into a swimming pool full of avgas, it would simply go out.
Try and think of a candle, you can put a naked flame on a candle and nothing will happen other than the wax melting. Light the wick and the wax...
Or an American one, an Israeli one, A British one.
Rupture the tanks and let the jet engine ignite the rest.
Avgas is fairly benine, it requires an ignition sorce.