Seen an explosion from liquid alkanes entering a vacuum pump.
The lab I was visiting had 1 vacuum pump with a T leading to their vacuum oven AND evacuating their CLS post extraction.
Well…one day they forgot to close the evac line and flooded the system.
When I noticed the vacuum pump spitting hazy clouds of liquid I pointed it out and went to close the evac valve. The other guy went to turn off the vac pump…big mistake…soon as he touched it a fireball erupted in his face