Chemical spill at Ultium EV battery plant pauses cathode mixing operations

WASHINGTON — Some operations at Ultium Cells LLC's battery plant in Warren, Ohio, remain paused after a chemical leak that is now under investigation by federal regulators.

The company confirmed Tuesday to Automotive News that "immediate steps" were taken to contain a cathode mixing slurry leak that occurred over the weekend at its Ohio production plant.

"The immediate surrounding area was cleared, and area mixing operations have been halted while we assess and address the situation," Ultium spokesperson Katie Burdette said in an emailed statement. "None of our operators were present in the area, and there has been no employee exposure or injuries."

Ultium — a joint venture between General Motors and South Korea's LG Energy Solution to produce battery cells for the automaker's electric vehicles — said its investigation into the cause of the spill is ongoing.

Operations in the cathode mixing area will remain paused until cleanup is complete and the area "has been inspected for damage and deemed safe," said Burdette, adding that Ultium has brought in a third-party company to assist with the cleanup.

Burdette did not provide an estimate on how long the cleanup could take. It is also unclear how the leak has affected battery cell production.

Ultium reported the incident Monday to the U.S. Labor Department's Occupational Safety and Health Administration, which also has opened an investigation into the matter.

An EPA spokesperson told Automotive News that the spill was not reported to the National Response Center, therefore the agency was not made aware.

“EPA will most likely not conduct an investigation unless assistance is requested by OSHA,” the spokesperson said.

The chemical leak and federal investigation were first reported by The Detroit News.

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.

The agency is still investigating the extent of exposure to the chemical leak, which contained N-Methylpyrrolidone (NMP), a solvent used for various purposes including cathode manufacturing. NMP can enter the body through skin contact or inhalation via vapor or spray droplets.

Overexposure to NMP can irritate the eyes, skin, nose and throat and affect the central nervous system and brain, causing symptoms of drunkenness similar to the effects of drinking alcohol.

OSHA could invoke the "General Duty Clause," which requires an employer to provide its employees with a workplace free from recognized hazards that could cause death or physical harm, if workers are becoming "seriously ill from NMP," 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.

In December, the UAW won an election at the Warren plant — marking the first and only unionized battery cell manufacturing plant in the U.S. — with workers voting 710-16 in favor of union representation. A contract is still being negotiated.

The union criticized conditions at the plant in a white paper released in July, arguing its workers have "reported serious health and safety problems" and face "hazardous conditions and low pay."

Ultium, which is a separate legal entity and independent employer from GM and LG, said in a letter to Sen. Sherrod Brown, D-Ohio, last month that it remains "committed to bargaining a fair agreement that allows Ultium Cells, our employees and the UAW to succeed in the EV future."

In a statement Monday, UAW President Shawn Fain called the chemical leak “the latest in a long line of serious health and safety hazards” that UAW members have faced at Ultium and “underscores why it is critically important that Ultium adopt the health and safety standards that generations of auto workers have fought for and won at General Motors.”

“These accidents are preventable and manageable,” he continued. “Sadly, Ultium is choosing to prioritize their bottom line over human safety.”

The UAW has been negotiating new labor contracts with GM, Ford and Stellantis. Those contracts expire Sept. 14.