Arc Flash Exhaust Ventilation

Working in an oil & gas setting, we are soon looking forward to installing a couple of new motor control centers. With regards to arc flash our switchgear will probably be something that in the event of an arc flash the effects (molten metal, explosion) most will go through the top into an exhaust system and out the side of a building. However these MCCs could be located relatively close to process units that house combustible gases; Will our exhaust system to the outside be an ignition source for these gases? We are considering installing a shaft or chimney that will direct the exhaust up and out. Any thoughts or ideas on how to deal with this or what you've done?

Thanks

That's a good one. It would probably be best to talk with AB, Cutler Hammer, Square D, etc. that makes arc resistant gear and see if they have run into this before. I can't imagine you are the first. It would be nice to see what the tell you posted here. Good Luck!