Five workers suffered chemical burns Wednesday from a release at the Wacker Polysilicon plant in northern Bradley County.
One worker was flown to Erlanger hospital in Chattanooga via Life Force, and four others were taken by ambulance to a hospital, Bradley County authorities said.
The Bradley County Sheriff's Office dispelled rumors of an explosion and said there was no danger to the community. An employee at nearby Walker Valley High School said school officials had not been warned of any danger or instructed to take protective measures.
The $2.5 billion plant manufactures hyperpure polysilicon in the manufacturing of solar panels. Work is underway now on a $150 million expansion.
William J. Toth, director of corporate communications and compliance for Wacker Chemical, said via email the accident happened around 11:45 a.m. Wednesday when "a small chemical release of silane was detected while performing routine maintenance."
Silane is a highly flammable compressed gas used in manufacturing. Federal Material Safety Data Sheets show the chemical may explode when mixed with air, or cause burns or frostbite if the rapidly expanding gas touches skin. It also is harmful if inhaled because it can displace oxygen and cause rapid suffocation.
Toth's email did not say how the release happened. It said the plant's incident response team was sent to the area and contained the release. It's not clear whether the workers doing maintenance or the response team members were the ones injured.
The email praised the actions of the incident response team and and said there was no risk to the community.
"Wacker's first and foremost priority is the safety and well-being of its team members, contractors and the community," Toth wrote in the email. He did not respond to questions about how the chemical release occurred or the workers' conditions.
Records from the Tennessee Office of Occupational Safety and Health Administration showed Wacker was cited and paid fines twice over dangerous working conditions since it opened in April 2016.
An inspection in March 2016 cited a violation of regulations related to control of hazardous energy, and the company paid a $3,500 fine that September.
In August 2016, violations related to process safety management of highly hazardous chemicals and respiratory protection cost the company $4,000.
In October, a faulty gasket in a distillation device released a small cloud of chemicals, but no one was injured and plant workers repaired the gasket.