WASHINGTON, DC -- The U.S. Chemical Safety and Hazard Investigation Board (CSB) released a new safety video on its investigation into the fatal release of hydrogen chloride at the Wacker Polysilicon North America facility in Charleston, Tennessee, that occurred on November 13, 2020. One contract worker was killed - and two others were seriously injured - when attempting to escape the release. 

The CSB's new safety video, called “No Way Down: Chemical Release at Wacker Polysilicon,” includes an animation of the events leading to the incident, as well as commentary from CSB Board Member Catherine Sandoval and CSB Lead Investigators Tyler Nelson and Drew Sahli. 

The CSB released its final investigation report on the incident at Wacker on June 15, 2023. The CSB’s investigation found that at the time of the incident there were multiple contract workers present on the fifth floor of an equipment access platform at the facility. The contract workers were from two different firms, conducting different work, and were wearing different levels of Personal Protective Equipment. One of the workers applied excessive torque to flange bolts on a heat exchanger outlet pipe containing hydrogen chloride, causing the pipe to crack and release the hazardous chemical in the vicinity of the workers.

There was only one way to exit the platform – via a staircase. As the white cloud of hydrogen chloride expanded, the workers on the platform were not able to see their surroundings or access the staircase. Three of the workers who were not wearing full-body chemical resistant suits began climbing down the side of the structure to escape the hazardous cloud. All three workers fell approximately 70 feet during their attempt to escape. One of the workers died from the fall, and the other two sustained serious injuries.

In the safety video, Board Member Catherine Sandoval says, “This tragic incident was completely preventable.”  She added: “What should have been fairly straightforward maintenance activity by two separate groups of workers turned deadly because of several serious safety issues. The CSB believes that our findings and recommendations will address the issues found at Wacker and prevent another needless tragedy.”

The safety video addresses the key safety issues identified in the CSB’s final report that contributed to the incident: (i) the need for written procedures, (ii) control of hazardous energy, (iii) greater guidance on simultaneous operations, and (iv) improved means of egress.  The video highlights safety recommendations made by the CSB to Wacker Polysilicon, the Occupational Safety and Health Administration, the Center for Chemical Process Safety, the International Code Council, and the National Fire Protection Association. 

The CSB is an independent federal agency charged with investigating incidents and hazards that result, or may result, in the catastrophic release of extremely hazardous substances. The agency’s core mission activities include conducting incident investigations; formulating preventive or mitigative recommendations based on investigation findings and advocating for their implementation; issuing reports containing the findings, conclusions, and recommendations arising from incident investigations; and conducting studies on chemical hazards.

The agency's board members are appointed by the president subject to Senate confirmation. The Board does not issue citations or fines but makes safety recommendations to companies, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA.