State investigation returns 7 violations against Wacker for Sept. 7 explosion [document]

Staff photo by Doug Strickland / A plume billows from the Wacker polysilicon chemical plant after an explosion released a hydrochloric acid on Sept. 7, 2017, in Charleston, Tenn. The plant has had three chemical releases in two weeks.

A state investigation into a Sept. 7 explosion at the Wacker Polysilicon plant returned five serious violations and two "other-than-serious" violations ranging from failing to properly train employees to not following generally accepted good engineering practices.

The company must pay more than $25,000 in fines or legally challenge the Tennessee Occupational Safety and Health Administration report. A TOSHA investigation into a separate incident at Wacker that sent five employees to area hospitals with chemical burns a week prior to the explosion was released last week. That investigation found two serious violations and resulted in more than $20,000 in fines for the company.

The TOSHA report for the Sept. 7 explosion found Wacker failed to conduct necessary inspections; did not ensure materials, parts and equipment were suitable for what they were being used for; along with other violations.

"At Wacker, we are continually working to ensure the safety of our site, our team members, our community, and our environment. We are committed to providing safe and secure jobs in our community," reads a statement from company vice president and Wacker-Charleston site manager Mary Beth Hudson.

photo Clouds billow from the Wacker polysilicon chemical plant after an explosion released a hydrogen chemical gas on Thursday, Sept. 7, 2017, in Charleston, Tenn. The explosion closed the plant, but a statement from Wacker says air quality was unaffected.

The explosion at the $2.5 billion plant resulted in a plant worker, a firefighter, four deputies and seven local residents being treated at local hospitals. It also caused several schools to go on lockdown.

Wacker announced Wednesday that the Sept. 7 incident was caused by a mechanical failure in the company's hydrogen recovery building.

"A new piston, part of an upgraded compressor design purchased last year, fractured, resulting in the release of hydrogen that ignited. To restart the plant, we will be returning to our original compressor design that has operated safely for decades at Wacker sites and many other global companies," according to a statement.

TOSHA only investigates incidents related to employee safety. A separate Tennessee Department of Environment and Conservation investigation could return additional fines and citations.

Wacker ceased production at the plant while it independently investigated the cause of the explosion.

"We have been working with an outside independent expert over the last several months to analyze the origin and cause of the September 7th incident as we prepare for the restart of facility operations," Hudson wrote. "The independent team brought decades of global experience and has assisted in identifying key information related to the incident."

Contact staff writer Mark Pace at or 423-757-6659. Follow him on Twitter @themarkpace and on Facebook at ChattanoogaOutdoorsTFP.