Officials say Benjamin Franklin High School and Science Leadership Academy, which share a campus in Spring Garden, will be closed on Tuesday, October 1 and Wednesday, October 2.
"I'm a little concerned, I don't want to end up sick or nothing," said Dalnick Matos, a senior at Science Leadership Academy.
The School District of Philadelphia and the Philadelphia Federation of Teachers will meet regularly to review the progress and determine the status of re-opening on Thursday, October 3.
The issues were identified during recent environmental safety walkthroughs.
Officials said there was damaged insulation material in the campus boiler room, and testing confirmed it contained asbestos.
Asbestos fibers were also detected at a low concentration in the Science Leadership Academy common area, which is currently under construction.
The campus will be closed for abatement and further testing.
"Those things should not be occurring when children are there, so we will be taking those actions," said Superintendent William Hite.
The discovery comes in the wake of a $37 million construction project. The project was supposed to be completed in July, but that didn't happen.
Already this school year, the school district addressed asbestos concerns over at William M. Meredith Elementary in Queen Village.
Last month, the Philadelphia Federation of Teachers called for an immediate $100 million investment to eliminate lead and asbestos from every school building after they say a longtime teacher at Meredith was diagnosed with mesothelioma, which has been linked to long-term exposure to asbestos.
The teacher has worked in district schools for three decades.
Photos obtained by Action News show apparent asbestos in the gym at Meredith.
The school district acknowledged they have many older buildings with asbestos and lead-based paint, but add they have comprehensive protocols to assess and monitor conditions to ensure students and staff are safe.
The district couldn't give an exact number on how many of its schools have asbestos or lead, but the majority of their 220 schools are over 70-80 years old.
The district reports they have completed more than 1600 asbestos remediation projects in the last three years.
This fiscal year alone, between capital and operating budgets, the district has set aside $20.7 million, specifically for asbestos abatement and lead paint repairs and assessments in schools, but district officials acknowledge they need more funding and must prioritize issues.
Arthur Frank who is a professor at Drexel University at the department of environmental and occupational health said the school district should have known there was asbestos in the school before school started, and testing should have been done.
"Not only before school started, it should have been done decades ago, and they should have known exactly where the asbestos was in that building, they should know that for every school building in Philadelphia," said Frank.
If an immediate threat is identified, they say that the area is shut down.
School district officials said they will make a decision on Wednesday to see if it's safe for students to return to school on Thursday.
Families, media and the public are urged to monitor the District website at www.philasd.org