There isn't supposed to be any ignition source in this engineered and controlled environment. If such an ignition source existed, someone must have brought it into the controlled area.
Not entirely true and that’s why I “speculate”. Vapor control is a requirement in this instance.
I have recently reported several local instances of trucks loading over gasoline vapors while not connected to the vapor control system at our terminal. This is a violation of Federal Law but if the drivers can get away with it and save time...they will!
Had to install BIG signs telling the drivers that they are in violation and that we will report them.
As it regards this issue, we’ll have to wait for the forensics to point the accusatory finger...