What on earth do they use for ripen the bananas? I've heard that earlier they used some explosive gas for it, but nowadays..?

the incident: there was a storage, where bananas were aged before sending into the stores. One day, one wall of the storage blew 500 meters away on the field. Bananas were found even further. From my point of view, it was fun as hell, but I understood that neighbours weren't that happy, when bananas started falling on their roofs

They use Ethene aka Ethylene aka C2H6. Apples give off that gas when they ripen, so if you put a bunch of apples in plastic bag, you should be able to collect some. It is not useful as an explosive, though.

~Snake

It's a hydocarbon, though, isn't it? It should work more or less like methane when mixed with air. You could indeed cause an explosion with it, but there's really no point. At the rate you would have to ferment apples to collect it you could just buy a propane tank.

Apparently it can be used to have fun in poorly ventilated fruit warehouses, though. I suspect there's some sort of regulation about that, but you know how those things go.

~Zero the Inestimable