Abstract: Employee #1 and coworkers were performing research on ceramics. They set a refractory block on a copper table, set a ceramic tube on the block, and placed both the block and the table inside heating coils before enclosing everything with a glass cover. Hydrogen and the extremely volatile chemical methyl trichlorosilane (MTS), were run through the system for 22 hours. Afterward, argon and then air were run through the system to oxidize the MTS. The ceramic was left to sit for 48 hours over the weekend. After this period for oxidation, Employee #1 and coworkers began using metal scrapers to remove the residue created by the process. Employee #1's metal scraper created some friction that generated sparks; the sparks ignited the flammable MTS vapors that had not been oxidized. The vapors exploded into a ball of fire. Employee #1 sustained burns to his right arm and face.