The Philadelphia School District and its teachers’ union on Thursday moved toward a possible showdown over plans to reopen schools next week, with teachers questioning whether it’s safe to return to buildings and Superintendent William R. Hite Jr. saying he expected them to do so.

Days after criticism erupted over the district’s plan to use window fans to improve ventilation during the COVID-19 pandemic, Philadelphia Federation of Teachers president Jerry Jordan called on the city to assign a neutral third party to assess if buildings are ready for reopening Monday.

Hite acknowledged that the expert’s opinion — an option open to the PFT under terms of a reopening agreement signed by the union and district last fall — could “possibly delay” students’ return for in-class instruction. It would be the third such change in reopening plans since last summer.

But, the superintendent said, “it will not delay our expectations for teachers to be in classrooms” on Feb. 8.

Neither Jordan nor Hite has been willing to speculate on what would happen if the two can’t reach agreement on reopening conditions. But Chicago teachers have refused to report to schools over building conditions, forcing the district to scuttle its reopening plans. A strike is possible there.

Members of the Caucus of Working Educators, an activist group within the PFT, have said they support school staff who refuse to report to buildings over safety concerns.

Amber Cialone, the music teacher at Elkin Elementary, isn’t sure she’ll step foot inside the Kensington school Monday.

“I know a lot of people are really considering their options,” said Cialone, a second-year teacher. “I’ll be on campus, I don’t know whether that will be sitting in my car, doing school from my car. Teachers want to go back, but they want to go back under safe conditions.”

After months of back-and-forth and meetings with district officials, Jordan said he had deep concerns over ventilation, especially in schools where window fans are being installed to improve airflow, and other safety issues.

But the superintendent said Thursday that even if a room doesn’t meet ventilation standards, a single teacher could still occupy it.

» READ MORE: Window fans may be Philly’s fix for schools with poor ventilation. But teachers and parents are saying no way.

Jordan insists that “the schools are not ready for staff or children to return.”

About 9,000 staff who work with prekindergarten through second-grade children are due back at work next week; some students in those grades are eligible to return Feb. 22. The families of about 9,000 children opted to resume in-person education two days a week — most families chose to keep their children learning remotely.

COVID-19 has kept Philadelphia students out of classrooms since last March. The district twice attempted reopening buildings — once, in September, when community pushback changed officials’ minds, and then in November, when rising case counts shut down plans.

Hite, in a statement, said: “It is disappointing that, at this time, when there is already so much uncertainty for our families due to COVID-19, the union has chosen this course of action in an attempt to delay the reopening of our school buildings.” He said the district was “fully committed to the agreed upon mediation process.”

Jordan said he’s been asking questions about building readiness in letters and in meetings, but has been frustrated by a lack of information. The district has made ventilation reports available, but some are incomplete and others show no safe occupancy in key areas like hallways and bathrooms.

Reggie McNeil, the district’s chief operating officer, said Tuesday that the school system had installed 37% of the 1,100 window fans it needs to improve airflow in schools with no or little mechanical ventilation. He said the rest would be installed in time for the Monday return, but Jordan said he was told this week that some fans wouldn’t be installed until Sunday.

That doesn’t leave enough time for the air balancing testing or for reports to be updated and shared publicly, as the district has promised, Jordan said.

“I need answers before my members go back into buildings,” he said.

Hite said Thursday that even if air balancing tests were not completed by Monday, teachers could return because “one individual can be in a space, even if that space is a zero on ventilation. You’re not sharing air with anyone else.”

» READ MORE: Will Philly’s third attempt at school reopening stick? Teachers are wary and parents are split.

The PFT also has qualms about the fans’ use, worries that teachers and many parents share. Photos of the window fans, mounted on plywood planks, circulated widely on social media. People concerned about the reopening plan have spent the week reaching out to Mayor Jim Kenney and other elected officials via phone, email, and other means, voicing their displeasure over school conditions.

Lauren Cox, a city spokesperson, said Philadelphia’s Labor Department is in talks with a mediator, and will share details once that person is confirmed.

By Thursday, more than 5,000 people had signed a petition started by a Germantown mother to halt reopening for now.

“I believe it is still unsafe to put our children in the buildings,” Maya McGeathey wrote in her petition. “As we all know, they are very old and have poor or little ventilation. The ventilation that the district is offering is unacceptable, not just for the students, but for the staff as well.”

Hite, though, said Thursday the fans were a “good-faith effort to provide fresh air into classrooms,” adding that some other school districts around the country “simply did that by opening windows.” He said the district has spent $4 million on ventilation efforts; it was unclear how much of that was for the fans.

Trust in the school system, particularly around building issues, is low, given the district’s track record around environmental hazards. And recently, a botched $50 million construction job at Benjamin Franklin High sickened students and staff over more than a year. In the 2019-20 school year, 10 schools were forced to close over damaged asbestos.