On May 11, 2022, a significant deflagration occurred at a pilot plant in North Chicago, resulting in extensive damage to the building’s first floor. The explosion originated in a room connected to the chemical drain system, after 100 liters of a hexane-acetone mixture followed by 100 liters of acetone were sent into the facility's chemical drain.
Vapors from these solvents migrated into the subject room through a dry floor drain and formed a flammable vapor cloud, which was subsequently ignited by an unidentified ignition source. The explosion caused substantial mechanical damage but fortunately resulted in no sustained fire. The organization engaged Engineering Systems Inc. (ESi) to investigate the incident, determine the root causes, and provide actionable recommendations to prevent recurrence.