Justices uphold $5.8 million award against Tyson Foods

Justice Anthony Kennedy wrote the majority opinion that upheld lower court rulings in favor of employees of Springdale, Arkansas-based Tyson.

The workers sued to be paid for time spent putting on and taking off protective work clothes and equipment before wielding sharp knives in slaughtering and processing the animals.

The company and business groups that supported it pressed the court to elaborate on its 2011 decision blocking a massive sex-discrimination case against Wal-Mart Stores Inc. that would have included up to 1.6 million female workers.

The opinion relied on a 70-year-old Supreme Court decision that allows workers to use statistical evidence in lawsuits over compensation when their employer doesn't keep adequate records of their hours.

In 2010, it settled a decade-long 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.