The Irving Fire Department's hazardous materials teams responded to two calls within two hours at 8500 South Freeport Parkway.
The Irving Fire Department's hazardous materials team was on the scene of two separate calls at the same building Monday morning.
According to Irving Assistant Fire Chief Tony Harvey two calls came in from a six-story building that houses several businesses the 8500 South Freeport Parkway.
The first call came in at 8:25 a.m. about a fire in the electrical room. At 10:25 a.m. the fire department received a call about a chlorine odor.
Firefighters determined the odor was coming from a broken clean out line on an air conditioner, a chemical had been added to keep it from clogging and getting moldy.
Three people were taken to the hospital for medical attention.