Teachers at Masterman say asbestos — and a lack of answers from the Philadelphia School District over the potential environmental hazard — makes their school building unsafe, and they don’t want to set foot inside until officials demonstrate otherwise.

The staff plan on working outside their Spring Garden Street building starting Thursday.

“We do not feel safe in the building,” said Ethan Tannen, a Masterman math teacher.

Tannen and more than 50 other school staff sent a letter Wednesday to Superintendent William R. Hite Jr., the school board, and Mayor Jim Kenney expressing their concerns about the school’s environmental conditions. Though Philadelphia’s students are not yet in school, teachers are working this week to prepare for them.

When asked to comment, the Philadelphia School District responded with a statement:

“We will continue to be available to address these matters with our stakeholders,” said Monica Lewis, a district spokesperson.

According to Masterman teachers, parents, and Jerry Roseman, the Philadelphia Federation of Teachers’ environmental director, more than 60 areas of damaged asbestos have been identified in the school, with imminent hazards identified in the art room and in a second-floor bathroom, as well as damaged material and dust above drop ceilings, district documents and federal asbestos inspection reports show. The district had said that hundreds of feet of that damaged asbestos would be removed, but it has not been, Roseman said.

Undamaged asbestos is harmless. But when disturbed, its tiny fibers pose potentially serious health risks.

Roseman said he has been concerned about conditions at Masterman for “a number of months.”

Construction work is ongoing at the school, with a roof replacement project underway. It is unclear whether the construction is related to the asbestos.

With the exception of a relatively small number of students who returned two days a week over the spring, children have been out of the building since March 2020. They are set to return to the building Tuesday.

“We want to get back to teaching children and promoting their growth, and we will find a way to work outside of the building” until demands around transparency and environmental safety are met, the educators wrote in their letter.

The district has a long history of environmental trouble — problems with lead paint and asbestos, and issues remediating those risks safely. Most recently, a disastrous major construction project at Benjamin Franklin High School displaced more than 1,000 students, wasted millions of dollars, and endangered the health of staff and children, according to an Inquirer investigation and the district’s inspector general.

Masterman staff want Kenney, City Council, and the school board to order the district to release all environmental documents, reports, and other information related to asbestos, and they want clearer answers about conditions at Masterman and at any other school where environmental hazards may be present. They are asking for better cooperation from the administration with the Philadelphia Federation of Teachers, too.

“We have already seen what might happen if these issues are ignored, with the terminal cancer diagnosis of our colleague caused by asbestos exposure in district buildings,” the teachers wrote in their Wednesday letter.

Lea DiRusso, a longtime district teacher, was diagnosed with mesothelioma, a lethal, asbestos-linked cancer, after working in schools with known damaged asbestos. The School District paid DiRusso an $850,000 settlement in 2020.

“These conditions should not exist at Masterman,” Masterman staff wrote in their letter. “They should not exist at McClure. They should not exist at Ben Franklin. They should not exist in any building in the School District of Philadelphia. To know that we are safe, and to know that our students are safe, we need more information, and we need it now.”

The teachers’ action builds on information Masterman parents have been asking for over several years. At first, parents trusted the district and believed the school — an elite city magnet that serves children from all over Philadelphia and often ranks at the top of all public schools in the state — was up to par, physically. They began to worry as they learned of asbestos in a storage closet often used by the parents’ group.

“It’s not that we were complacent, it’s just that we believed what they were telling us,” said Barbara Dallao, chair of the parents’ group’s environmental committee. Dallao said the district has let areas of imminent hazard fester at the school for years.

The district tried to block parents from getting records, and at times has underplayed or outright lied about asbestos hazards, Dallao said. Eventually, the group got some of the information it was seeking via a Freedom of Information Act request, which showed the latest asbestos risks.

Not making full information easily available “is flipping the bird, and not taking our student and teacher safety seriously,” Dallao said. Parents said that the district needs outside oversight of asbestos jobs going forward and that Masterman is just the tip of the iceberg.

“This fight is for our school and our teachers,” Dallao said, “but it is also our fight for every school, especially those in the most underprivileged areas, who may not know the extent of what’s going on.”