According to a Tweet from Atlanta Fire Rescue, the leak happened at 1 Lemon Lane NE, which is the address of Schwan Food Company.
An emergency alert was sent to cell phones in the area just before 3:30 p.m. The message said to "shelter in place immediately" and to avoid going outdoors as a precautionary measure. "Close all windows and doors. Turn off ventilation and HVAC systems," it added.
About an hour later, Atlanta Fire Rescue announced in a Tweet the shelter in place order was lifted. Atlanta Fire Department Battalion Chief Gary Robb told 11Alive the emergency alert was just a precaution to keep people in the area safe.
The fire department said several roadways were also blocked off. They initially urged people to avoid the intersection of Oakdale and DeKalb Avenue. Crews also shut down Arizona Avenue.
Atlanta Fire Department Battalion Chief Gary Robb told 11Alive it all started when workers were off loading 40,000 pounds of ammonia from a storage tank to a truck when a valve on that truck malfunctioned.
The workers were able to get away and call 911. Robb said first responders arrived and started pouring water on the gas to try and keep it low to the ground.
According to Robb, a portion of 22,000 pounds of ammonia leaked. He said the building, which is vacant, is in the process of being torn down.
Officials said no one was hurt.