Here's where my ignorance of anatomy comes in, but it might go into the lungs instead? Or both, if the pressure is enough, if the mouth is open, etc. Many threads ago someone posted the characteristics of the crude in those tanks, ie it was not heated. But then the source also said it was under some pressure, I think they said ambient pressure. The gas given off by the crude would probably go out of some piping, so as not to build up too much pressure in the tank, but how much pressure would remain in the product. I really don't know but have wondered that. Probably someone's oil industry wife/husband can tell us if that has any validity at all.