Abstract: On November 22, 1991, Employee #1 was loosening the experimental slurry in a 100 lb cylinder as part of a research and development project process. The cylinder had been placed on and secured to an inversion stand so that the slurry would mix/loosen for the transfer into a 200 gallon reaction vessel through a hose connection between the cylinder and the vessel. Employee #2 was ready to open the hose. Before the slurry could be charged into the vessel, the cylinder exploded, killing Employee #1 and seriously injuring Employee #2. A probable cause could be an exothermic reaction within the cylinder that resulted in instantaneous excessive pressure that detonated the cylinder.