The workers requested the Illinois state court issue an injunction, which would make McDonald's stop requiring workers to reuse masks, mandate face coverings for customers and require the company to inform employees if a coworker becomes infected.
Separately, McDonald's workers at three California locations on Tuesday filed administrative actions over allegedly unsafe conditions with the California Division of Occupational Safety and Health.
Employees at restaurants, warehouses and other essential businesses that remained open during the Covid-19 outbreak have protested and walked off the job over fears of getting sick.
Trade groups have warned of a wave of litigation over the pandemic, but few cases have been filed.
Retailer Walmart Inc and meat producers JBS SA and Tyson Foods Inc were each sued over employee deaths from Covid-19.
Smithfield Foods Inc [SFII.UL] was sued by a workers group demanding safety measures in a lawsuit that, like the McDonald's case, alleged the company was a public nuisance.
The Smithfield case was quickly dismissed because the judge said workplace conditions were a matter for the Occupational Safety and Health Administration, part of the Department of Labor.