Explosive gas in Advanced Generators (Minecraft mod)
This is Syngas - a new fuel source in Advanced Generators (http://bdew.net/generators/) that will be available in the next version.
Considering that the real life version is pretty volatile, i've decided to make it properly explosive in game if placed in the world.
The gas will explode if it touches open flame, lava, torches or burning entities (like mobs on fire, or fiery arrows). Also if a block is affected by explosion it will produce a secondary chain explosions so the whole area will blow up.