Years ago, WorkSafe British Columbia (BC) put out a really nice video about a fatality caused by a worker welding on a used Acetone Drum. Although the video states the drum is a 44-gallon drum, it is in fact a 55-gallon drum. 44 imperial gallons is equal to 52 US gallons – which we call a 55-gallon drum. But what caught my attention back then (2012) was how WorkSafe BC explained that only 1 teaspoon of liquid Acetone was all that is needed in a 55-gallon drum to achieve a flammable atmosphere! Now, we have this workshop from the University of Michigan College of Chemical Engineering – Process Safety Initiative Led by Professor H. Scott Fogler using this 2012 incident to explain how “Material and Energy Balances” play a role in Process Safety. This is the pure love of process safety and flammable liquids and gases (FLAGs) shown in a real working example: http://umich.edu/~safeche/assets/pdf/courses/Solutions/MaterialsAndEnergy/230Materials&EnergyModule(2)Soln-WeldingDrum.pdf
Be sure to check our Professor H. Scott Fogler’s homepage at the University of Michigan – it is full of great Process Safety teaching materials and challenges.