DHEC says toxic vapors from Elgin chemical leak pose no risk to public, environment

ELGIN – A leak at a chemical plan in Kershaw County released thousands of pounds of emissions containing toxins into the air on July 27, according to a report from the company’s internal investigation.

The leak at the WeylChem US plant, about 5 miles northeast of Columbia, sent a cloud of vapors containing nitric acid and nitrogen oxide into the air. Those nearby the plant said there was a distinct, unpleasant smell in the air.

Wind pushed the cloud away from a nearby neighborhood and over Interstate 20, preventing a mass evacuation. A portion of I-20 was closed as a precaution until the leak was under control and evening traffic on the interstate was routed through a long detour for several hours.

The S.C. Department of Health and Environmental Control has reviewed the report, filed Aug. 26, and determined that the vapors containing nitric acid and nitrogen oxide do not pose a serious risk to public health or the environment.

“While even low concentrations of acid vapors can be irritating to the eyes, nose, mouth or lungs, review of this release indicates there was no serious health risk to people or the environment,” according to DHEC spokeswoman Laura Renwick.

Winds saved Elgin residents from toxic vapor after chemical plant spill

WeylChem has a DHEC-issued air permit that covers nitrogen oxide emissions and the department is continuing to review the facility’s nitrogen oxide emissions to determine whether there have been any violations, according to the spokeswoman.

DHEC will also conduct unannounced inspections relating to the regulations under the air permit and the Environmental Protection Agency’s Risk Management Program, the spokeswoman added.

A total of 2,745 pounds of emissions containing nitric acid, nitrogen oxide and water leaked after an equipment failure, according to an incident report the company was required to file with DHEC.

Most of the emissions were released over a span of five hours and 15 minutes when a temporary line to reroute the vapors was installed, WeylChem US CEO Mark Matheny wrote in the report. The report said a “small localized release” continued until 9 p.m. on July 29, two days later.

The perimeter of the plant within 0.2 miles was evacuated and water was used as a suppression to limit the vapors until the leak could be safely stopped, according to the report.

“We are not aware of any reasons for concern,” Matheny said in a statement. “As stated in the information we provided, there were no injuries to any WeylChem US employees and have not been made aware of any impact to the community.”

Residents evacuated, interstate closed after SC chemical plant spill

Due to disclosure limitations with a customer, Matheny could not discuss specifics on the process involving the chemicals.

“Other than a small area of the plant that was impacted, we were at full operation and all employees, including administration, were on site and working as normal within 12 hours of the release,” Matheny said in a statement.

DHEC’s spokeswoman added that the department has requested additional information from WeylChem about the nitric acid released from the facility.

Under EPA’s Risk Management Program, nitric acid must be regulated if it is stored at a quantity of 15,000 pounds or more and at a concentration of 80 percent or more. Without going into specifics, Renwick said WeylChem does not store nitric acid at that concentration and said “by definition, the total amount released is not considered major.”

“We’ve determined that the nitric acid substance that was released does not meet the requirement for being regulated under the EPA’s Risk Management Program regulations for hazardous substances,” Renwick said in a statement. “Therefore, no further investigation is needed.”


Fire crews respond to a toxic chemical release at the WeylChem plant in Elgin, about 25 miles from downtown Columbia on July 27.

Frank Taylor/staff

September 19, 2022 
 Post and Courier, The (Charleston, SC) 
 Charleston, South Carolina
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