PHILADELPHIA (CBS) — The union representing Philadelphia school teachers is telling its members not to report to school on Monday. The Philadelphia Federation of Teachers is in a standoff with the Philadelphia School District over the safety of school buildings.

Teachers were due back in classrooms on Monday to begin preparations for students to return on Feb. 22.

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The union says the city has appointed a neutral arbitrator to hear both sides, but they have yet to hear a date of when that hearing will happen.

“I am going to be meeting with members of the PFT after their workday today and we’re going to discuss the topic,” Philadelphia Federation of Teachers President Jerry Jordan said.

Union leaders say they’ve received a number of pictures and heard from teachers who have visited their schools, giving examples of safety concerns.

“From what I’ve seen, it runs the gamut of pictures, first of all, of the fans,” Jordan said.

From pictures to fans, the school district spent $4 million on ventilation upgrades, including adding fans to windows to mitigate the spread of COVID-19.

“One member who was in his school yesterday said that the room was 48 degrees. None of us want to sit in a 48-degree room for a full day. And for the children, it would mean they would need to have their coats and hats and gloves on,” Jordan said.

In a meeting Friday night, union leaders instructed teachers to be available remotely but remain home.

“Ventilation has been a big issue. It’s been an issue for forever it feels like,” teacher Charlotte McCracken said.

McCracken is a science specialist teacher at Bache-Martin Elementary School. And though she says she prefers teaching her students in-person, she supports the union’s decision to keep all instructors home, especially because she feels the district’s attempts at retrofitting the classrooms was done without too much planning.

“That’s where I want to be. I want to be in my building when it’s safe. We had 11 months, and I don’t know, to put in a fan like that, it just seems like they pushed the paper to the night before it was due, and now here we are. I’m ready to go back, but I’m ready to go back to a building that is ready for me,” McCracken said.

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The teachers’ union is waiting on a third party to mediate their safety issues before signing off on a Monday return. Now, three City Council members and two state legislators are calling for a delay in returning to schools.

Councilmember Jamie Gauthier has two children in the school district and wants the pause on reopening plans.

“We’re calling for there to be public trust and confidence among the school community, including teachers and parents and principals before we rush to a school reopening,” Gauthier said.

The notice affects teachers in grades kindergarten through second that were preparing for hybrid learning. Other classes and grades are unaffected.

Philadelphia School District Superintendent Dr. William Hite says several steps have been taken so students and staff can return to school safely.

The school district said in a statement Friday afternoon, “It is deeply disappointing that PFT has directed their members to disregard the District’s plan to return staff to buildings in preparation for the return of PreK to second-grade students on Feb. 22. This is in violation of our collective bargaining agreement and the Memorandum of Agreement that PFT reached regarding the reopening of schools just a few months ago. What is more troubling is that this action directly impacts our efforts to support the more than 9,000 PreK to second-grade families who want their children to return to school buildings for in-person learning.”

Monday’s action was discussed at Friday’s union meeting for the teachers. We’re told the plan is still in place for the teachers to remain at home this Monday and be present virtually. Two weeks from now, students are expected back in class but that was not discussed at tonight’s meeting.

CBS3’s Natasha Brown and Greg Argos contributed to this report.

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