A chlorine dioxide leak was found at a water filtration plant Monday, prompting the evacuation of about 1,500 people in homes and businesses, officials said.

No injuries were reported and there were no workers inside the equipment building where the leak occurred, city spokeswoman Lyn Garris said. An alarm on an electronic monitor signaled the leak at about 4:30 a.m., and it was stopped within an hour, Garris said.

Between 4 and 25 pounds of chlorine dioxide gas leaked from a device that pulsates small amounts of the chlorine mixture into the water as a disinfectant. The mixture, which is less toxic than chlorine, is a severe respiratory and eye irritant in humans, according to the Occupational Safety and Health Administration.

The drinking water has been tested and is safe, Garris said. None of the chlorine was detected outside of the plant area, but residents were evacuated as a precaution, she said.