Operations have been restored at Ultium Cells LLC’s battery plant in Warren, Ohio, after a chemical leak temporarily halted activity in the cathode mixing area, the company confirmed Wednesday.

An Ultium spokesperson did not provide details on when cathode mixing operations resumed or whether an internal investigation of the leak is still underway.

The company said it took “immediate steps” to contain a cathode mixing slurry leak that occurred over the weekend at its Ohio production plant. Area mixing operations had been paused while Ultium assessed the situation and worked with a third-party company on the cleanup. Operations at other parts of the plant were not affected.

No employees were exposed or injured in the spill, the company said.

Ultium — a joint venture between General Motors and South Korea’s LG Energy Solution to produce battery cells for the automaker’s electric vehicles — reported the incident Monday to the U.S. Labor Department’s Occupational Safety and Health Administration, which has opened an investigation into the matter.

OSHA spokesperson Scott Allen said the agency is collecting information from Ultium “as to the details of what happened, what actions they took to address them and whether employees are still at risk.”

Based on the information received, OSHA will then determine whether employees were exposed to a significant hazard, whether actions taken by Ultium were appropriate and whether there is enough information to establish a potential violation of workplace safety and health standards to warrant citations, Allen said.

OSHA has six open inspections at Ultium’s Warren plant and five closed inspections.

To date, the company has paid $31,078 in fines for violations of OSHA workplace laws. In some cases, penalties were reduced or waived, Allen said.