Here is a recent article by Sarah Anne Hughes  writer for theincline.com discussing the details of the fight.

The ordinance, which grants most private sector employees the right to paid days off for illness, was challenged by the Pennsylvania Restaurant and Lodging Association and local businesses just one month after it passed in 2015. An Allegheny County Court of Common Pleas judge ruled against the city in December 2015, saying that Pittsburgh as a second-class city doesn’t have the ability to dictate the actions of private businesses.

The City of Pittsburgh, with Service Employees International Union Local 32BJ, appealed that ruling, arguing that Pennsylvania law grants second-class municipalities the right to “make regulations to secure the general health of the inhabitants.” But Commonwealth Court rejected that, as well as the city’s other arguments.

“We recognize that paid sick leave for employees is a laudable goal,” Judge Michael H. Wojcik wrote in Wednesday’s order. “The power to achieve that goal rests with our General Assembly, however, through statewide legislation addressing paid sick leave or, alternatively, through legislation vesting authority to do so in local municipalities.”

As the lone dissenter, Judge Joseph M. Cosgrove wrote that the “case involves an effort to protect health and safety.”

“That indeed is what municipalities are for,” Cosgrove continued. “In exercise of the political power to do so, the present ordinance was enacted. If the people of Pittsburgh disagree with this action, they will address their dissatisfaction through the political process. It is not for this court to interfere.”

Pittsburgh plans to appeal the ruling to the Pa. Supreme Court, according to a spokesperson for Mayor Bill Peduto.

In a statement, Sam Williamson of SEIU 32BJ said the union is “disappointed but not surprised by the decisions from the Commonwealth Court.”

“Yesterday, Pittsburghers voted overwhelmingly to continue the progress of the last four years and keep building a Pittsburgh for all. Harrisburg shouldn’t get in the way of cities and towns doing what we know is best for our residents,” he continued. “Right now, we have to remove the burden of state preemption, so our city can build a strong economy that works for all. We look forward to taking this fight for all Pittsburghers to the Pennsylvania Supreme Court.”