Toxic gas releases at Ohio, Tennessee explosives plants under investigation

VINTON COUNTY, Ohio (WOWK/NEXSTAR) – The U.S. Chemical Safety and Hazard Investigation Board (CSB) has launched an investigation into the release of toxic gas at Austin Powder Company facilities in Ohio and Tennessee. The company manufactures explosives.

The first incident happened Nov. 24, 2024 at the Austin-owned U.S. Nitrogen facility in the Midway community of Greene County, Tennessee, according to the CSB. Austin Powder released a statement shortly after the gas release, blaming it on a “malfunction” during the start-up of the nitric acid plant.

The second incident happened June 11 at the commercial explosives manufacturing plant near McArthur in Vinton County, Ohio.

According to state officials, the release occurred after “an unknown contaminant” entered a 5,000-gallon tank containing nitric acid and purportedly caused a chemical reaction that released nitrogen oxide gas. 

Local officials evacuated everyone within three miles of the plant; the Federal Aviation Administration reportedly barred flights from entering the airspace up to a 30-nautical-mile radius above the facility.

In both cases, a large, brownish-colored plume of the gas covered the facility and much of the immediate surrounding area. 

CSB Chairperson Steve Owens said in a statement, “We are concerned that incidents involving nitric acid have occurred at two facilities owned by Austin Powder in less than seven months.  While fortunately no one was injured in either incident, we want to ensure that they do not continue to happen.” 

Emergency management officials ordered an evacuation of a three-mile radius around the facility, and hundreds of residents in the nearby community of Zaleski were also evacuated.

The Federal Aviation Administration also temporarily restricted flights for a 30-nautical-mile radius surrounding the facility.

The CSB says they will be working with other local, state, and federal officials to assess the situation and determine the path forward.