The U.S. Chemical Safety and Hazard Investigation Board (CSB; Washington, D.C.; www.csb.gov) has released a second update on the agency’s ongoing investigation of the November 12, 2024, explosion at the Givaudan Sense Colour facility in Louisville, Kentucky.
The explosion fatally injured two employees and seriously injured three others. Large metal fragments of equipment were thrown up to 400 feet away from the facility, damaging nearby homes and businesses and prompting local officials to issue a shelter-in-place order for a one-mile radius. The facility has since ceased operations and is being demolished.
The facility was producing caramel food coloring in a batch reactor at the time of the incident. To determine whether the materials being processed in the reactor on the day of the incident experienced a hazardous “runaway” reaction, the CSB conducted laboratory reactivity tests on representative samples of the materials. The CSB testing confirmed that the materials that were in the reactor could result in a hazardous runaway reaction and cause an explosion like the one that occurred last November—even within the reactor’s normal operating limits. The tests showed rapid and dangerously high increases in both pressure and temperature occurring far beyond the reactor’s safe limits as the materials were processed, with pressures exceeding 1,500 psig and temperatures rising over 280°F during the testing. Gases, consisting primarily of carbon dioxide, were produced during these reactions, contributing to the increase in pressure.
The CSB continues to examine the causes of the explosion, including equipment analysis and evaluation of the reactor’s relief system. A final report with findings and safety recommendations will be issued upon completion of the investigation.
The CSB is an independent federal agency responsible for investigating industrial chemical incidents that result—or could result—in catastrophic releases of hazardous substances. The Board conducts thorough investigations, issues safety recommendations, and advocates for preventive measures to protect workers, communities, and the environment.
Board members are appointed by the President and confirmed by the Senate. The CSB does not issue fines or citations but makes non-binding safety recommendations to companies, labor organizations, regulatory bodies, and industry stakeholders.