CSB releases video animation of fatal 2021 Yenkin-Majestic explosion

The U.S. Chemical Safety and Hazard Investigation Board (CSB) recently released a new safety video on its investigation into the massive April 8, 2021, explosion and fire that fatally injured one worker at the Yenkin-Majestic Paint Corporation in Columbus, Ohio.

The CSB's new safety video, “Low Pressure, Fatal Consequence: Explosion at Yenkin-Majestic,” includes an animation of the incident and commentary from Sylvia Johnson, CSB board member, and Melike Yersiz, investigator-in-charge.

The CSB’s final investigation report on the incident was released Nov. 2023.

Operator inadvertently triggered failure of repaired manway

On the evening of April 7, 2021, during a batch operation to produce resin, an operator inadvertently added a flammable solvent to a low-pressure vessel called a kettle while the agitator was unexpectedly off. As a result, the solvent did not mix with the resin as intended and instead formed a liquid layer on top of the hot resin.

When the kettle’s operator discovered the agitator was off, he turned it back on. But as the agitator began mixing the hot resin with the liquid solvent layer, the solvent suddenly vaporized, increasing the pressure inside the kettle rapidly. This led to the failure of the kettle’s new manway that was installed approximately three months before the incident.

A flammable vapor cloud quickly spread throughout the facility and within minutes found an ignition source, causing a massive explosion and a large fire that burned for roughly 11 hours. One employee, Wendell Light, died during the incident, and eight other workers were injured.

Recommendations made to company, API, ASME

“The CSB’s investigation determined that Yenkin-Majestic failed to ensure the mechanical integrity of the newly installed manway, which was not adequately designed, constructed, or pressure tested. The company also lacked engineering controls that could have prevented the incident and did not have adequate emergency response preparations in place,” Johnson said in the video. “The result was a tragic accident that could have been prevented.”

The video covers three key safety issues from the CSB’s final report that contributed to the incident

1. Mechanical integrity of low-pressure vessels
2. Safeguard selection and the hierarchy of controls
3. Emergency preparedness

The video also highlights safety recommendations made by the CSB to Yenkin-Majestic, the American Petroleum Institute (API), and the American Society of Mechanical Engineers (ASME).