Using dry Dimethyl Sulfoxide (DMSO) as solvent, a reaction between an organic macrocycle and bromoethane was placed in a round bottom pressure vessel. The reaction was heated using armor aluminum beads in a stainless steel bowl sitting atop a hotplate. The setup was briefly left unattended inside a fume hood with the sash closed.
Without a means for temperature control, the hotplate generated excess heat, which in turn produced excess pressure. Overpressurization caused the round bottom vessel to shatter. Glass shards along with the aluminum heating beads sprayed across the enclosed fume hood, causing several parts of the fume hood sash to crack.