A graduate student researcher was consolidating aqueous nitric acid solutions into a 4-L bottle marked as hazardous waste. The bottle was stored inside a fume hood along with other waste bottles, organic reagent bottles, a hotplate and an oil bath. The fume hood sash was left open when all researchers left at the end of the day.
Several hours later, a custodian entered the lab and saw broken glass and brown liquid on the floor. It appears that the nitric acid waste was stored in a bottle that contained residual organic compounds, the combination of which generated sufficient pressure to shatter the holding vessel and the surrounding glassware.