MILWAUKEE — Workers at a Wisconsin meat processing plant must be paid for time spent putting on and taking off protective clothing, an appeals court ruled Thursday.

The ruling came in a lawsuit filed by six workers at the Tyson Prepared Foods Inc., plant in Jefferson. The lawsuit is one of several filed nationwide by meat and poultry workers, who say they spend significant time putting on and taking off gear that can include hair nets, hard hats, shoe covers, safety glasses and frocks, which are like coats with snaps in front.

The Jefferson County Circuit Court had said Tyson did not have to pay workers for that time because putting on and taking off the gear wasn't essential to their duties. The 4th District Court of Appeals disagreed, saying it counted as "preparatory and concluding" activities that were an integral part of their jobs. It sent the case back to the circuit court to determine how much the workers should be paid.

"It's a big victory for these Tyson workers," said Douglas Phebus, the attorney representing the workers. He has asked for class-action status, so the decision will affect all the workers in the plant.

Phebus estimated the back pay could total more than $1 million. He said he hadn't yet had a chance to talk to the six workers who filed the lawsuit because they were working, but he spoke with the president of the union that represents them and "they're happy."

Tyson spokesman Worth Sparkman said in an email that the company was disappointed in the appeals court decision and was evaluating its options for further defense of the case.

Tyson's plant in Jefferson primarily produces pepperoni for pizza toppings. Some of the protective clothing is worn in part to prevent food contamination, as well as to protect workers, the appeals court noted.

Springdale, Ark.-based Tyson Foods Inc. has faced similar litigation around the country. In 2010, it settled a decadelong dispute with the U.S. Department of Labor by agreeing to pay workers at some poultry plants for time they spent putting on and taking off protective clothing. The Labor Department reached a similar deal with poultry processor Pilgrim's Pride Corp. the same year, and Cargill Meat Solutions Corp. agreed to settle a similar case in Nebraska in 2011.

Businesses and labor advocates have argued for years over whether workers must be paid for tasks such as putting on sanitary gear, walking to a work site or waiting for work to begin. The U.S. Supreme Court ruled in 2005 that such activities should be paid, but Tyson and other companies said the full scope of the court's decision was not clear.