The three-story building was found to have potentially dangerous levels of asbestos, mercury, arsenic, lead and other substances during a routine inspection in December.
School officials had hoped to reopen the Science Building by the end of winter break, but announced last week that the facility, which contains labs, classrooms and lecture halls that accommodate more than 9,000 students, would remain closed through the semester. The spring semester started Monday.
Classes have been moved to alternate locations in conference rooms, computer labs, classrooms, and chemistry and engineering labs in other buildings, school officials said.
Existing trailers on campus are also being retrofitted to accommodate engineering and chemistry lab classes, and some classes will likely move into those trailers later in the semester.
Two engineering lab classes have been canceled because of the Science Building closure.
More tests and evaluations are underway at the shuttered building, school spokeswoman Ellen Griffin said. The school has yet to determine whether the hazardous materials may have affected student and employee health, she said.