The affected areas are the media office, auditorium, east gym, wrestling room and coaches' room, and several science classrooms.
The district worked closely with Needham Risk Management, CS Arch and Camroden Associates to plan for possible mitigation efforts.
Testing involves leaving charcoal canisters in the affected areas for several days. They are then sealed and sent the Department of Health and the school district's health consultant to determine action.
"We consider the health and safety of our students and staff to be our highest priority, and will continue to communicate with you throughout the testing process as further information becomes available," according to a message posted on the district's Web site.""