A southeastern Tennessee chemical plant will remain closed until safety officials can determine what caused a massive explosion that released a cloud of hydrochloric acid over a town a town and sent several people to the hospital with chemical burn injuries.
The Sept. 7 explosion at the Wacker Polysilicon plant in Charleston, Tennessee, about 40 miles northwest of Chattanooga, was the second incident in a week to rock the plant and send workers to a nearby hospital.
A Wacker official told the press that the two incidents were unrelated, but a joint investigation by the Occupational Safety and Health Administration (OSHA) and the Tennessee Occupational Safety and Health Administration (TOSHA) could determine whether the explosion and the earlier incident could be attributed to safety violations.
The Wacker plant manufactures hyperpure silicon for solar panels using chlorosilane, which forms hydrochloric acid when exposed to air.
According to Chattanooga’s Times Free Press, last week’s explosion sent a plant worker, a firefighter, four deputies, and seven local residents to the hospital with injuries. The release of hydrochloric acid also put the town and nearby communities on lockdown, as authorities shut down a section of I-95 and several roads, and told people to stay indoors and turn off air conditioning systems.
Hydrochloric acid can cause chemical burns if touched, inhaled, or ingested.
The Times Free Press said the chemical release continued Thursday for six hours, and hydrogen chemicals escaped even after emergency responders thought the leak had been contained.
On Aug. 30, five workers suffered chemical burns following a chemical release of chlorasilane at the plant. It’s uncertain whether that incident was connected somehow to the explosion last week.
“Asked multiple times whether chlorosilane was the cause in both cases, (Wacker Communications and Executive Coordinator Lisa) Mantooth dodged the question. Another Wacker employee, who was present for the briefing but not introduced, said it was,” the Times Free Press reported.
Because the Sept. 7 accident occurred while the Aug. 30 accident was under investigation, a probe of the earlier incident was being expanded to include the latest mishap at the plant, officials said.