UAW workers at a Ford-supplying plant in suburban Detroit began striking Wednesday after nine failed negotiation meetings. The Constellium Automotive plant produces aluminum structures and crash management systems for the Ford F-150, F-150 Lightning, Explorer and Super Duty at six assembly plants.

The 160 workers on strike are concerned about health and safety issues at the plant and management’s disciplinary practices, according to a UAW statement. The union said they have filed unfair labor practice charges against the company for bad-faith bargaining.

“Our negotiating team has met with the company nine times since April 18,” UAW Region 1A Director Laura Dickerson said in a statement. “And on every single occasion, Constellium has made it very clear they have zero interest in taking our members’ proposals seriously.”

A spokesperson for Constellium said negotiations should resume soon. “We do not anticipate any disruption to our production and will work closely with our customers to ensure continuity of operations. Negotiations are resuming this week and our goal is to reach a mutually beneficial agreement.”

The plant is in Van Buren, Mich., just west of Detroit. Constellium, of Paris, France, ranks No. 84 on Automotive News‘ list of the top 100 global parts suppliers, with estimated worldwide sales to automakers of $1.9 billion in its 2021 fiscal year.

Meanwhile, Wednesday marked the tenth day of a UAW strike at a Clarios battery plant near Toledo. Negotiations are ongoing but Clarios and the UAW have not reached a resolution yet.

The strike involves more than 400 workers and began in response to failed negotiations about overtime pay and other concerns.

The plant supplies batteries to automotive assembly lines at Ford and General Motors. So far, there have been no reports of production disruptions.

“We are aware of the situation and monitoring it closely,” a GM spokesperson said. The plant supplies 12-volt batteries to GM plants in the U.S. and Canada.

The UAW filed charges against Clarios with the National Labor Relations Board on May 5, alleging the company was guilty of refusing to bargain or of bargaining in bad faith and refusal to furnish information.

A spokesperson for Clarios did not say whether the company plans to file its own charges.

“We’re committed to bargaining with the union in good faith,” the spokesperson said. “At the same time, the union has the right to file a claim. We look forward to the review process, and to also arriving at a fair agreement for both sides to resolve the strike.”

Clarios, based in Milwaukee and formerly part of Johnson Controls Inc., ranks No. 75 on Automotive News‘ list of the top 100 global parts suppliers, with estimated worldwide sales to automakers of $2.5 billion in its 2021 fiscal year.