RALEIGH, N.C. — City Hall in Raleigh was evacuated for about an hour Wednesday after reports of a chemical spill in the basement where the county 911 communications office is.

Cleaning crews were using a drain cleaner that contains sulfuric acid, which caused an odor throughout the building, officials said. Usually, crews use the cleaner when the building is closed.

There were some reports of people complaining of throat irritation, but no one was treated.

Hazmat and fire crews ventilated the building and diluted the cleaner with water, authorities said.

Emergency communications and the county's 911 system were not affected.

Hargett Street between Dawson and McDowell streets was temporarily closed to accommodate fire apparatus.