is oil vapor flammable
The fire was caused by the ignition of hydrocarbon vapor released during the off-loading of basic sediment and water (BS&W) from the two vacuum trucks into an open area collection pit. BS&W is an oil/gas exploration and production (E&P) waste liquid. The BS&W was contaminated with highly flammable condensate. During the off-loading, vapor off-gassed from the BS&W and was drawn into the air intakes of the vacuum trucks' running diesel engines. As a result, the engines began to race and backfire.