The U.S. House chamber at the Capitol will reopen Tuesday morning after an unknown material was found behind a wall, and crews were concerned it might have contained asbestos.
The chamber was closed to tours out of precaution for much of Monday while the material was tested. It was discovered Monday morning during an ongoing renovation of the House Gallery.
"Some materials behind the wall panels could not be identified, so the Architect of the Capitol stopped work and tested them. The test results show that none of the materials were found to contain asbestos," said a statement from the Architect of the Capitol (AOC)'s office shortly before 5 p.m. Monday.
A Capitol Hill official told NBC earlier Monday that such a discovery is not out of the ordinary.
Regular operations will resume Tuesday, the AOC said.
Congress is currently on its regularly scheduled recess.
The renovation project -- which will restore gallery seats and replace fabric wall panels -- began July 31. Crews are also replacing floor tiles and refinishing brass railings. Work is scheduled to be performed mostly during House recess periods, and should be finished by the of of 2016.
The last major renovation of the gallery was done in the 1940s, the AOC said.