The U.S. Chemical Safety and Hazard Investigation Board (CSB) released an update on March 3 into its ongoing investigation into the fatal Nov. 12, 2024, explosion at the Givaudan Sense Colour facility in Louisville, Kentucky. The food additive plant produces the caramel color commonly used in soft drinks.
The incident killed two employees and seriously injured three others. After the explosion, reporters from The Courier-Journal documented the extensive property damage to the facility and nearby homes and businesses.
What Happened?
According to CSB’s investigation, operators at the facility began a process to produce caramel coloring for a food product in a batch reactor. The pressure in the reactor began to exceed the setpoint, and despite attempts to reduce it, continued to rise. The reactor ruptured when the pressure reached 237 psig, over three times the reactor’s maximum allowable pressure.
CSB said after the incident it was discovered the reactor vessel’s automated vent valve, designed to automatically open to relieve pressure in the vessel, was almost fully closed. CSB will further investigate by inspecting the recovered vent valve and actuator, conducting raw-materials testing, analyzing the batch reactor relief system, reviewing process data and evaluating emergency-response efforts.
“This massive explosion should not have happened," said CSB Chair Steve Owens in a press statement. "Two people died, homes and businesses were severely damaged, and the neighboring community was put at serious risk.”
Incident History
This is not the first fatal incident the CSB has investigated at the plant. In 2003, when D.D. Williamson & Co. owned and operated the plant, a process vessel became overpressurized and failed, releasing aqueous ammonia, damaging the facility and killing one worker.
